Spironolactone, sold under the brand name Aldactone among others, is a
medication
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and ...
that is primarily used to treat
fluid build-up due to
heart failure,
liver scarring, or
kidney disease.
It is also used in the treatment of
high blood pressure,
low blood potassium
Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an abnor ...
that does not improve with
supplementation,
early puberty
In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. In a minority of childr ...
in boys,
acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
and
excessive hair growth in women, and as a part of
transgender hormone therapy
Transgender hormone therapy, also called hormone replacement therapy (HRT) or gender-affirming hormone therapy (GAHT), is a form of hormone therapy in which sex hormones and other hormonal medications are administered to transgender or gender non ...
in
transfeminine
A transgender (often abbreviated as trans) person is someone whose gender identity or gender expression does not correspond with their sex assigned at birth. Many transgender people experience dysphoria, which they seek to alleviate through ...
people.
[ Spironolactone is taken ]by mouth
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...
.[
Common ]side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s include electrolyte abnormalities
Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function, ...
, particularly high blood potassium
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasi ...
, nausea, vomiting, headache, rashes, and a decreased desire for sex.[ In those with liver or kidney problems, extra care should be taken.][ Spironolactone has not been well studied in pregnancy and should not be used to treat ]high blood pressure of pregnancy
Hypertensive disease of pregnancy, also known as maternal hypertensive disorder, is a group of high blood pressure disorders that include preeclampsia, preeclampsia superimposed on chronic hypertension, gestational hypertension, and chronic hypert ...
. It is a steroid that block
Block or blocked may refer to:
Arts, entertainment and media Broadcasting
* Block programming, the result of a programming strategy in broadcasting
* W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 ...
s the effects of the hormone
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are require ...
s aldosterone and testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...
and has some estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
-like effects. Spironolactone belongs to a class of medications known as potassium-sparing diuretic
Potassium-sparing diuretics refers to drugs that cause diuresis without causing potassium loss in the urine. They are typically used as an adjunct in management of hypertension, cirrhosis, and congestive heart failure. The steroidal aldostero ...
s.[
Spironolactone was discovered in 1957, and was introduced in 1959.] It is on the World Health Organization's List of Essential Medicines
The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...
. It is available as a generic medication.[ In 2020, it was the 51st most commonly prescribed medication in the United States, with more than 13million prescriptions.
]
Medical uses
Spironolactone is used primarily to treat heart failure, edematous conditions such as nephrotic syndrome or ascites
Ascites is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdominal size, increased weight, a ...
in people with liver disease
Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common.
Signs and symptoms
Some of the si ...
, essential hypertension, low blood levels of potassium, secondary hyperaldosteronism
Hyperaldosteronism is a medical condition wherein too much aldosterone is produced by the adrenal glands, which can lead to lowered levels of potassium in the blood (hypokalemia) and increased hydrogen ion excretion (alkalosis).
This cause of min ...
(such as occurs with liver cirrhosis
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage causes tissue repai ...
), and Conn's syndrome
Primary aldosteronism (PA)'','' also known as primary hyperaldosteronism or Conn's syndrome, refers to the excess production of the hormone aldosterone from the adrenal glands, resulting in low renin levels and high blood pressure. This abnormalit ...
(primary hyperaldosteronism). The most common use of spironolactone is in the treatment of heart failure. On its own, spironolactone is only a weak diuretic
A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics i ...
because it primarily targets the distal nephron (collecting tubule
The collecting duct system of the kidney consists of a series of tubules and ducts that physically connect nephrons to a minor calyx or directly to the renal pelvis. The collecting duct system is the last part of nephron and participates in elect ...
), where only small amounts of sodium
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...
are reabsorbed, but it can be combined with other diuretics to increase efficacy. The classification of spironolactone as a "potassium-sparing diuretic" has been described as obsolete. Spironolactone is also used to treat Bartter's syndrome due to its ability to raise potassium levels.
Spironolactone has antiandrogenic activity. For this reason, it is frequently used to treat a variety of dermatological condition
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this ...
s in which androgens play a role. Some of these uses include acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
, seborrhea
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest numbe ...
, hirsutism
Hirsutism is excessive body hair on parts of the body where hair is normally absent or minimal. The word is from early 17th century: from Latin ''hirsutus'' meaning "hairy". It usually refers to a "male" pattern of hair growth in a female that ...
, and pattern hair loss
Pattern hair loss (also known as androgenetic alopecia (AGA)) is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front ...
in women. Spironolactone is the most commonly used medication in the treatment of hirsutism in the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
. High doses of spironolactone, which are needed for considerable antiandrogenic effects, are not recommended for men due to the high risk of feminization
Feminization most commonly refers to:
* Feminization (biology), the hormonally induced development of female sexual characteristics
* Feminization (activity), a sexual or lifestyle practice where a person assumes a female role
* Feminization (soci ...
and other side effects. Spironolactone can be used to treat symptoms of hyperandrogenism
Hyperandrogenism is a medical condition characterized by high levels of androgens. It is more common in women than men. Symptoms of hyperandrogenism may include acne, seborrhea (inflamed skin), hair loss on the scalp, increased body or facia ...
, such as due to polycystic ovary syndrome
Polycystic ovary syndrome, or PCOS, is the most common endocrine disorder in women of reproductive age. The syndrome is named after the characteristic cysts which may form on the ovaries, though it is important to note that this is a sign and no ...
, in women, dose of 50-100mg in 1 or 2 doses.
Heart failure
While loop diuretics
Loop diuretics are diuretics that act on the Na-K-Cl cotransporter along the thick ascending limb of the loop of Henle in the kidney. They are primarily used in medicine to treat hypertension and edema often due to congestive heart failure or c ...
remain first-line for most people with heart failure, spironolactone has shown to reduce both morbidity and mortality in numerous studies and remains an important agent for treating fluid retention, edema, and symptoms of heart failure. Current recommendations from the American Heart Association are to use spironolactone in patients with NYHA Class II-IV heart failure who have a left ventricular ejection fraction
An ejection fraction (EF) is the volumetric fraction (or portion of the total) of fluid (usually blood) ejected from a chamber (usually the heart) with each contraction (or heartbeat). It can refer to the cardiac atrium, ventricle, gall bladder, ...
of less than 35%.
In a randomized evaluation
A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical te ...
which studied people with severe congestive heart failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, ...
, people treated with spironolactone were found to have a relative risk of death of 0.70 or an overall 30% relative risk reduction
In epidemiology, the relative risk reduction (RRR) or efficacy is the relative decrease in the risk
In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with ...
compared to the placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures.
In general, placebos can af ...
group, indicating a significant death
Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...
and morbidity
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
benefit of the medication. People in the study's intervention arm also had fewer symptoms of heart failure and were hospitalized less frequently. Likewise, it has shown benefit for and is recommended in patients who recently had a heart attack
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which ma ...
and have an ejection fraction less than 40%, who develop symptoms consistent with heart failure, or have a history of diabetes mellitus
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...
. Spironolactone should be considered a good add-on agent, particularly in those patients "not" yet optimized on ACE inhibitors
Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. They work by causing relaxation of blood vessels as well as a decrease in blood volume ...
and beta-blockers. Of note, a recent randomized, double-blinded study of spironolactone in patients with symptomatic heart failure with "preserved" ejection fraction (i.e. >45%) found no reduction in death from cardiovascular events, aborted cardiac arrest, or hospitalizations when spironolactone was compared to placebo
A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures.
In general, placebos can af ...
.
It is recommended that alternatives to spironolactone be considered if serum creatinine
Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass).
Biological relevance
Serum creatinine (a blood measurement) is an importa ...
is greater than 2.5 mg/dL (221 μmol/L) in males or greater than 2 mg/dL (176.8 μmol/L) in females, if glomerular filtration rate
Renal functions include maintaining an acid–base balance; regulating fluid balance; regulating sodium, potassium, and other electrolytes; clearing toxins; absorption of glucose, amino acids, and other small molecules; regulation of blood pre ...
is below 30 mL/min or with a serum potassium of greater than 5.0 mEq/L given the potential for adverse events detailed elsewhere in this article. Doses should be adjusted according to the degree of kidney function as well.
According to a systematic review, in heart failure with preserved ejection fraction
An ejection fraction (EF) is the volumetric fraction (or portion of the total) of fluid (usually blood) ejected from a chamber (usually the heart) with each contraction (or heartbeat). It can refer to the cardiac atrium, ventricle, gall bladder, ...
, treatment with spironolactone did not improve patient outcomes. This is based on the TOPCAT Trial examining this issue, which found that of those treated with placebo had a 20.4% incidence of negative outcome vs 18.6% incidence of negative outcome with spironolactone. However, because the p-value of the study was 0.14, and the unadjusted hazard ratio
In survival analysis, the hazard ratio (HR) is the ratio of the hazard rates corresponding to the conditions characterised by two distinct levels of a treatment variable of interest. For example, in a clinical study of a drug, the treated populati ...
was 0.89 with a 95% confidence interval of 0.77 to 1.04, it is determined the finding had no statistical significance. Hence the finding that patient outcomes are not improved with use of spironolactone. When blood samples from 366 participants in the TOPCAT study were analyzed for presence of canrenone
Canrenone, sold under the brand names Contaren, Luvion, Phanurane, and Spiroletan, is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone which is used as a diuretic in Europe, including in Italy and Belgium. It ...
(an active metabolite of spironolactone), 30% of blood samples from Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
lacked detectable residues of canrenone. This led to the conclusion that the TOPCAT trial results in Russia do not reflect actual clinical experience with spironolactone in patients with preserved ejection fraction. The TOPCAT study results are now considered to have been invalidated. The study's prime investigator and other prominent research cardiologists are now advising physicians treating heart failure with preserved ejection fraction to consider prescribing spironolactone pending outcome of two multicenter trials of newer medications.
Due to its antiandrogenic properties, spironolactone can cause effects associated with low androgen levels and hypogonadism
Hypogonadism means diminished functional activity of the gonads—the testes or the ovaries—that may result in diminished production of sex hormones. Low androgen (e.g., testosterone) levels are referred to as hypoandrogenism and low estroge ...
in males. For this reason, men are typically not prescribed spironolactone for any longer than a short period of time, e.g., for an acute exacerbation of heart failure. A newer medication, eplerenone
Eplerenone, sold under the brand name Inspra, is an aldosterone antagonist type of potassium-sparing diuretic that is used to treat chronic heart failure and high blood pressure, particularly for patients with resistant hypertension due to ele ...
, has been approved by the U.S. Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
for the treatment of heart failure, and lacks the antiandrogenic effects of spironolactone. As such, it is far more suitable for men for whom long-term medication is being chosen. However, eplerenone may not be as effective as spironolactone or the related medication canrenone
Canrenone, sold under the brand names Contaren, Luvion, Phanurane, and Spiroletan, is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone which is used as a diuretic in Europe, including in Italy and Belgium. It ...
in reducing mortality from heart failure.
The clinical benefits of spironolactone as a diuretic are typically not seen until 2–3 days after dosing begins. Likewise, the maximal antihypertensive effect may not be seen for 2–3 weeks.
Unlike with some other diuretics, potassium supplementation should ''not'' be administered while taking spironolactone, as this may cause dangerous elevations in serum potassium levels resulting in hyperkalemia
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasi ...
and potentially deadly abnormal heart rhythms.
High blood pressure
About 1 in 100 people with hypertension have elevated levels of aldosterone; in these people, the antihypertensive effect of spironolactone may exceed that of complex combined regimens of other antihypertensives since it targets the primary cause of the elevated blood pressure. However, a Cochrane review
Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health profes ...
found adverse effects at high doses and little effect on blood pressure at low doses in the majority of people with high blood pressure. There is no evidence of person-oriented outcome at any dose in this group.[
]
High aldosterone levels
Spironolactone is used in the treatment of hyperaldosteronism (high aldosterone levels or mineralocorticoid excess), for instance primary aldosteronism
Primary aldosteronism (PA)'','' also known as primary hyperaldosteronism or Conn's syndrome, refers to the excess production of the hormone aldosterone from the adrenal glands, resulting in low renin levels and high blood pressure. This abnormalit ...
(Conn's syndrome). Antimineralocorticoids like spironolactone and eplerenone
Eplerenone, sold under the brand name Inspra, is an aldosterone antagonist type of potassium-sparing diuretic that is used to treat chronic heart failure and high blood pressure, particularly for patients with resistant hypertension due to ele ...
are first-line treatment
A therapy or medical treatment (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a medical diagnosis.
As a rule, each therapy has indications and contraindications. There are many different ...
s for hyperaldosteronism. They improve blood pressure and potassium levels, as well as left ventricular hypertrophy
Left ventricular hypertrophy (LVH) is thickening of the heart muscle of the left ventricle of the heart, that is, left-sided ventricular hypertrophy and resulting increased left ventricular mass.
Causes
While ventricular hypertrophy occurs ...
, albuminuria
Albuminuria is a pathological condition wherein the protein albumin is abnormally present in the urine. It is a type of proteinuria. Albumin is a major plasma protein (normally circulating in the blood); in healthy people, only trace amounts of ...
, and carotid intima-media thickness, in people with primary aldosteronism. In people with hyperaldosteronism due to unilateral aldosterone-producing adrenocortical adenoma, adrenalectomy
Adrenalectomy (Latin root Ad "near/at" + renal "related to the kidneys" + Greek '' ‑ectomy'' “out-cutting”; sometimes written as ADX for the procedure or resulting state) is the surgical removal of one ( unilateral) or both (bilateral) adr ...
should be preferred instead of antimineralocorticoids. Spironolactone should not be used to treat primary aldosteronism in pregnancy due to its antiandrogen-related risk of teratogenicity in male fetuses.
Skin and hair conditions
Androgens like testosterone and DHT play a critical role in the pathogenesis
Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...
of a number of dermatological conditions including oily skin
The human skin is the outer covering of the body and is the largest organ of the integumentary system. The skin has up to seven layers of ectodermal tissue guarding muscles, bones, ligaments and internal organs. Human skin is similar to mos ...
, acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
, seborrhea
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest numbe ...
, hirsutism
Hirsutism is excessive body hair on parts of the body where hair is normally absent or minimal. The word is from early 17th century: from Latin ''hirsutus'' meaning "hairy". It usually refers to a "male" pattern of hair growth in a female that ...
(excessive facial/body hair growth in women), and male pattern hair loss (androgenic alopecia). In demonstration of this, women with complete androgen insensitivity syndrome
Complete androgen insensitivity syndrome (CAIS) is an AIS condition that results in the complete inability of the cell to respond to androgens. As such, the insensitivity to androgens is only clinically significant when it occurs in individuals ...
(CAIS) do not produce sebum
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest nu ...
or develop acne and have little to no body
Body may refer to:
In science
* Physical body, an object in physics that represents a large amount, has mass or takes up space
* Body (biology), the physical material of an organism
* Body plan, the physical features shared by a group of anima ...
, pubic
In vertebrates, the pubic region ( la, pubis) is the most forward-facing (ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior r ...
, or axillary hair
Underarm hair, also known as axillary hair, is the hair in the underarm area (''axilla'').
Development
Underarm or axillary hair goes through four stages of development, driven by weak androgens produced by the adrenal in males and females du ...
. Moreover, men with congenital 5α-reductase type II deficiency, 5α-reductase being an enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
that greatly potentiates the androgenic effects of testosterone in the skin, have little to no acne, scanty facial hair, reduced body hair, and reportedly no incidence of male-pattern hair loss. Conversely, hyperandrogenism
Hyperandrogenism is a medical condition characterized by high levels of androgens. It is more common in women than men. Symptoms of hyperandrogenism may include acne, seborrhea (inflamed skin), hair loss on the scalp, increased body or facia ...
in women, for instance due to polycystic ovary syndrome
Polycystic ovary syndrome, or PCOS, is the most common endocrine disorder in women of reproductive age. The syndrome is named after the characteristic cysts which may form on the ovaries, though it is important to note that this is a sign and no ...
(PCOS) or congenital adrenal hyperplasia
Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by impaired cortisol synthesis. It results from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cort ...
(CAH), is commonly associated with acne and hirsutism as well as virilization
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens.
Virilization is most commonly used in three medical and biology ...
(masculinization) in general. In accordance with the preceding, antiandrogen
Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the ...
s are highly effective in the treatment of the aforementioned androgen-dependent skin and hair conditions.
Because of the antiandrogenic activity of spironolactone, it can be quite effective in treating acne in women. In addition, spironolactone reduces oil that is naturally produced in the skin and can be used to treat oily skin. Though not the primary intended purpose of the medication, the ability of spironolactone to be helpful with problematic skin and acne conditions was discovered to be one of the beneficial side effects and has been quite successful. Oftentimes, for women treating acne, spironolactone is prescribed and paired with a birth control pill
The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: progesti ...
. Positive results in the pairing of these two medications have been observed, although these results may not be seen for up to three months. Spironolactone has been reported to produce a 50 to 100% improvement in acne at sufficiently high doses. Response to treatment generally requires 1 to 3 months in the case of acne and up to 6 months in the case of hirsutism. Ongoing therapy is generally required to avoid relapse of symptoms. Spironolactone is commonly used in the treatment of hirsutism in women, and is considered to be a first-line antiandrogen for this indication. Spironolactone can be used in the treatment of female-pattern hair loss
Pattern hair loss (also known as androgenetic alopecia (AGA)) is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front ha ...
(pattern scalp hair loss in women). There is tentative low quality evidence supporting its use for this indication. Although apparently effective, not all cases of female-pattern hair loss are dependent on androgens.
Antiandrogens like spironolactone are male-specific teratogens which can feminize male fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal dev ...
es due to their antiandrogenic effects. For this reason, it is recommended that antiandrogens only be used to treat women who are of reproductive age in conjunction with adequate contraception. Oral contraceptives, which contain an estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
and a progestin, are typically used for this purpose. Moreover, oral contraceptives themselves are functional antiandrogens and are independently effective in the treatment of androgen-dependent skin and hair conditions, and hence can significantly augment the effectiveness of antiandrogens in the treatment of such conditions.
Spironolactone is not generally used in men for the treatment of androgen-dependent dermatological conditions because of its feminizing side effects, but it is effective for such indications in men similarly. As an example, spironolactone has been reported to reduce symptoms of acne in males. An additional example is the usefulness of spironolactone as an antiandrogen in transgender women.
Topical
A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...
spironolactone has been found to be effective in the treatment of acne as well. As a result, topical pharmaceutical formulations containing 2% or 5% spironolactone cream became available in Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
for the treatment of acne and hirsutism in the early 1990s. The products were discontinued in 2006 when the creams were added to the list of doping substances with a decree of the Ministry of Health that year.
Comparison
Spironolactone, the 5α-reductase inhibitor
5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism. There are three isozymes of ...
finasteride, and the nonsteroidal antiandrogen
A nonsteroidal antiandrogen (NSAA) is an antiandrogen with a nonsteroidal chemical structure. They are typically selective and full or silent antagonists of the androgen receptor (AR) and act by directly blocking the effects of androgens like ...
flutamide
Flutamide, sold under the brand name Eulexin among others, is a nonsteroidal antiandrogen (NSAA) which is used primarily to treat prostate cancer. It is also used in the treatment of androgen-dependent conditions like acne, excessive hair grow ...
all appear to have similar effectiveness in the treatment of hirsutism. However, some clinical research has found that the effectiveness of spironolactone for hirsutism is greater than that of finasteride but is less than that of flutamide. The combination of spironolactone with finasteride is more effective than either alone for hirsutism and the combination of spironolactone with a birth control pill is more effective than a birth control pill alone. One study showed that spironolactone or the steroidal antiandrogen cyproterone acetate
Cyproterone acetate (CPA), sold alone under the brand name Androcur or with ethinylestradiol under the brand names Diane or Diane-35 among others, is an antiandrogen and progestin medication used in the treatment of androgen-dependent condition ...
both in combination with a birth control pill had equivalent effectiveness for hirsutism. Spironolactone is considered to be a first-line treatment for hirsutism, finasteride and the steroidal antiandrogen cyproterone acetate are considered to be second-line treatments, and flutamide is no longer recommended for hirsutism due to liver toxicity concerns. The nonsteroidal antiandrogen bicalutamide
Bicalutamide, sold under the brand name Casodex among others, is an antiandrogen medication that is primarily used to treat prostate cancer. It is typically used together with a gonadotropin-releasing hormone (GnRH) analogue or surgical remo ...
is an alternative option to flutamide with improved safety
Safety is the state of being "safe", the condition of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk.
Meanings
There are two slightly dif ...
.
The combination of spironolactone with a birth control pill in the treatment of acne appears to have similar effectiveness to a birth control pill alone and the combination of a birth control pill with cyproterone acetate, flutamide, or finasteride. However, this was based on low- to very-low-quality evidence. Spironolactone may be more effective than birth control pills in the treatment of acne, and the combination of spironolactone with a birth control pill may have greater effectiveness for acne than either alone. In addition, some clinical research has found that flutamide is more effective than spironolactone in the treatment of acne. In one study, flutamide decreased acne scores by 80% within 3 months, whereas spironolactone decreased symptoms by only 40% in the same time period. However, the use of flutamide for acne is limited by its liver toxicity. Bicalutamide is a potential alternative to flutamide for acne as well. Spironolactone can be considered as a first-line treatment for acne in those who have failed other standard treatments such as topical therapies and under certain other circumstances, although this is controversial due to the side effects of spironolactone and its teratogenicity
Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology. The related ...
.
There is insufficient clinical evidence to compare the effectiveness of spironolactone with other antiandrogens for female-pattern hair loss. The effectiveness of spironolactone in the treatment of both acne and hirsutism appears to be dose-dependent, with higher doses being more effective than lower doses. However, higher doses also have greater side effects, such as menstrual irregularities
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia (vaginal bleeding between expected periods). The possible causes of irregular menstruation may vary. The common factors of ...
.
Alternative Spironolactone Use
Spironolactone medication is not approved for use as an antiandrogen by the Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
; instead, it is used off-label
Off-label use is the use of pharmaceutical drugs for an unapproved indication or in an unapproved age group, dosage, or route of administration. Both prescription drugs and over-the-counter drugs (OTCs) can be used in off-label ways, although ...
for such purposes.
Doses and forms
Spironolactone is typically used at a low dosage of 25 to 50 mg/day in the treatment of heart failure, while it is used at low to high dosages of 25 to 200 mg/day in the treatment of essential hypertension
Essential hypertension (also called primary hypertension, or idiopathic hypertension) is the form of hypertension that by definition has no identifiable secondary cause. It is the most common type affecting 85% of those with high blood pressure. T ...
, and at high dosages of 100 to 400 mg/day for hyperaldosteronism and ascites
Ascites is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdominal size, increased weight, a ...
due to cirrhosis
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage causes tissue rep ...
. The medication is typically used at high dosages of 100 to 200 mg/day in the treatment of skin and hair conditions in women, and at high dosages of 100 to 400 mg/day in feminizing hormone therapy for transgender women.
Spironolactone can be used to treat symptoms of hyperandrogenism
Hyperandrogenism is a medical condition characterized by high levels of androgens. It is more common in women than men. Symptoms of hyperandrogenism may include acne, seborrhea (inflamed skin), hair loss on the scalp, increased body or facia ...
, such as polycystic ovary syndrome
Polycystic ovary syndrome, or PCOS, is the most common endocrine disorder in women of reproductive age. The syndrome is named after the characteristic cysts which may form on the ovaries, though it is important to note that this is a sign and no ...
, in women, dose of 50-100mg in 1 or 2 doses.
Spironolactone is available in the form of tablets (25 mg, 50 mg, 100 mg; brand name Aldactone, others) and suspension
Suspension or suspended may refer to:
Science and engineering
* Suspension (topology), in mathematics
* Suspension (dynamical systems), in mathematics
* Suspension of a ring, in mathematics
* Suspension (chemistry), small solid particles suspende ...
s (25 mg/5 mL; brand name CaroSpir) for use by mouth
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...
. It has also been marketed in the form of 2% and 5% topical
A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...
cream
Cream is a dairy product composed of the higher-fat layer skimmed from the top of milk before homogenization. In un-homogenized milk, the fat, which is less dense, eventually rises to the top. In the industrial production of cream, this process ...
in Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
for the treatment of acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
and hirsutism
Hirsutism is excessive body hair on parts of the body where hair is normally absent or minimal. The word is from early 17th century: from Latin ''hirsutus'' meaning "hairy". It usually refers to a "male" pattern of hair growth in a female that ...
under the brand name Spiroderm, but this product is no longer available. The medication is also available in combination with other medications, such as hydrochlorothiazide
Hydrochlorothiazide is a diuretic medication often used to treat high blood pressure and swelling due to fluid build-up. Other uses include treating diabetes insipidus and renal tubular acidosis and to decrease the risk of kidney stones in ...
(brand name Aldactazide, others). Spironolactone has poor water solubility
An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be rep ...
, and for this reason, only oral and topical formulations have been developed; other routes of administration
A route of administration in pharmacology and toxicology is the way by which a medication, drug, fluid, poison, or other substance is taken into the body.
Routes of administration are generally classified by the location at which the substance i ...
such as intravenous injection are not used. The only antimineralocorticoid that is available as a solution
Solution may refer to:
* Solution (chemistry), a mixture where one substance is dissolved in another
* Solution (equation), in mathematics
** Numerical solution, in numerical analysis, approximate solutions within specified error bounds
* Soluti ...
for parenteral
A route of administration in pharmacology and toxicology is the way by which a drug, fluid, poison, or other substance is taken into the body.
Routes of administration are generally classified by the location at which the substance is applied. ...
use is the related medication potassium canrenoate
Potassium canrenoate ( INN, JAN) or canrenoate potassium (USAN) (brand names Venactone, Soldactone), also known as aldadiene kalium, the potassium salt of canrenoic acid, is an aldosterone antagonist of the spirolactone group. Like spironolact ...
.
Contraindications
Contraindication
In medicine, a contraindication is a condition that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of indication, which is a reason to use a certain tre ...
s of spironolactone include hyperkalemia
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasi ...
(high potassium levels), severe and end-stage kidney disease (due to high hyperkalemia risk, except possibly in those on dialysis), Addison's disease
Addison's disease, also known as primary adrenal insufficiency, is a rare long-term endocrine disorder characterized by inadequate production of the steroid hormones cortisol and aldosterone by the two outer layers of the cells of the adre ...
(adrenal insufficiency and low aldosterone levels), and concomitant use of eplerenone
Eplerenone, sold under the brand name Inspra, is an aldosterone antagonist type of potassium-sparing diuretic that is used to treat chronic heart failure and high blood pressure, particularly for patients with resistant hypertension due to ele ...
. It should also be used with caution in people with some neurological disorders
A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weaknes ...
, no urine production, acute kidney injury
Acute kidney injury (AKI), previously called acute renal failure (ARF), is a sudden decrease in kidney function that develops within 7 days, as shown by an increase in serum creatinine or a decrease in urine output, or both.
Causes of AKI are c ...
, or significant impairment of kidney excretory function with risk of hyperkalemia.
Side effects
One of the most common side effects of spironolactone is frequent urination
Frequent urination, or urinary frequency (sometimes called pollakiuria), is the need to urinate more often than usual. Diuretics are medications that increase urinary frequency. Nocturia is the need of frequent urination at night. The most common c ...
. Other general side effects include dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
, hyponatremia
Hyponatremia or hyponatraemia is a low concentration of sodium in the blood. It is generally defined as a sodium concentration of less than 135 mmol/L (135 mEq/L), with severe hyponatremia being below 120 mEq/L. Symptoms can be a ...
(low sodium
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...
levels), mild hypotension
Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dia ...
(low blood pressure), ataxia
Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements. Ataxia is a clinical manifestation indicating dysfunction of ...
(muscle incoordination), drowsiness
Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...
, dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness.
Dizziness is a common medical c ...
, dry skin
Xeroderma, xerosis or xerosis cutis, or simply dry skin, is a skin condition characterized by excessively dry skin.
The medical term ''xeroderma'', meaning "dry skin", derives from modern Latin, ''xero-'' 'dry' + Greek ''derma'' 'skin'.
In most ...
, and rash
A rash is a change of the human skin which affects its color, appearance, or texture.
A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...
es. Because of its antiandrogenic activity, spironolactone can, in men, cause breast tenderness
Breast pain is the symptom of discomfort in either one or both breasts. Pain in both breasts is often described as ''breast tenderness'', is usually associated with the menstrual period and is not serious. Pain that involves only one part of a br ...
, gynecomastia
Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse ( ...
(breast development), feminization
Feminization most commonly refers to:
* Feminization (biology), the hormonally induced development of female sexual characteristics
* Feminization (activity), a sexual or lifestyle practice where a person assumes a female role
* Feminization (soci ...
in general, and demasculinization
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens.
Virilization is most commonly used in three medical and biology ...
, as well as sexual dysfunction
Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction a ...
including loss of libido and erectile dysfunction, although these side effects are usually confined to high doses of spironolactone. At very high doses (400 mg/day), spironolactone has also been associated with testicular atrophy
Testicular atrophy is a medical condition in which one or both testicles (or "testes") diminish in size and may be accompanied by reduced testicular function. Testicular atrophy is not related to the temporary shrinkage of the surrounding scrotum, ...
and reversibly reduced fertility, including semen abnormalities such as decreased sperm count
A semen analysis (plural: semen analyses), also called seminogram or spermiogram, evaluates certain characteristics of a male's semen and the sperm contained therein. It is done to help evaluate male fertility, whether for those seeking pregna ...
and motility
Motility is the ability of an organism to move independently, using metabolic energy.
Definitions
Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...
in men. However, such doses of spironolactone are rarely used clinically. In women, spironolactone can cause menstrual irregularities
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia (vaginal bleeding between expected periods). The possible causes of irregular menstruation may vary. The common factors of ...
, breast tenderness
Breast pain is the symptom of discomfort in either one or both breasts. Pain in both breasts is often described as ''breast tenderness'', is usually associated with the menstrual period and is not serious. Pain that involves only one part of a br ...
, and breast enlargement Breast enlargement is the enlargement of the breasts. It may occur naturally as in mammoplasia or may occur artificially through active intervention. Many women regard their breasts, which are female secondary sex characteristics, as important to t ...
. Aside from these adverse effects, the side effects of spironolactone in women taking high doses are minimal, and it is well tolerated.
The most important potential side effect of spironolactone is hyperkalemia
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasi ...
(high potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...
levels), which, in severe cases, can be life-threatening. Hyperkalemia in these people can present as a normal anion-gap metabolic acidosis. It has been reported that the addition of spironolactone to loop diuretics in patients with heart failure was associated with a higher risk of hyperkalemia and acute kidney injury
Acute kidney injury (AKI), previously called acute renal failure (ARF), is a sudden decrease in kidney function that develops within 7 days, as shown by an increase in serum creatinine or a decrease in urine output, or both.
Causes of AKI are c ...
(AKI). Spironolactone may put people at a heightened risk for gastrointestinal issues like nausea, vomiting, diarrhea, cramping, and gastritis
Gastritis is inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain (see dyspepsia). Other possi ...
. In addition, there has been some evidence suggesting an association between use of the medication and bleeding
Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...
from the stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
and duodenum, though a causal relationship between the two has not been established. Also, spironolactone is immunosuppressive
Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse reacti ...
in the treatment of sarcoidosis
Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly a ...
.
Most of the side effects of spironolactone are dose-dependent. Low-dose spironolactone is generally very well tolerated. Even higher doses of spironolactone, such as 100 mg/day, are well tolerated in most individuals. Dose-dependent side effects of spironolactone include menstrual irregularities, breast tenderness and enlargement, orthostatic hypotension
Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when standing up or sitting down. Primary orthostatic hypertension is also often referred to as neurogenic orthostatic hyp ...
, and hyperkalemia. The side effects of spironolactone are usually mild and rarely result in discontinuation.
High potassium levels
Spironolactone can cause hyperkalemia, or high blood potassium levels. Rarely, this can be fatal. Of people with heart disease prescribed typical dosages of spironolactone, 10 to 15% develop some degree of hyperkalemia, and 6% develop severe hyperkalemia. At a higher dosage, a rate of hyperkalemia of 24% has been observed. An abrupt and major increase in the rate of hospitalization due to hyperkalemia from 0.2% to 11% and in the rate of death due to hyperkalemia from 0.3 per 1,000 to 2.0 per 1,000 between early 1994 and late 2001 has been attributed to a parallel rise in the number of prescriptions written for spironolactone upon the publication of the Randomized Aldactone Evaluation Study (RALES) in July 1999. However, another population-based study in Scotland
Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...
failed to replicate these findings. The risk of hyperkalemia with spironolactone is greatest in the elderly, in people with renal impairment
Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...
(e.g., due to chronic kidney disease or diabetic nephropathy
Diabetic nephropathy, also known as diabetic kidney disease, is the chronic loss of kidney function occurring in those with diabetes mellitus. Diabetic nephropathy is the leading causes of chronic kidney disease (CKD) and end-stage renal disease ...
), in people taking certain other medications (including inhibitors, angiotensin II receptor blocker
Angiotensin II receptor blockers (ARBs), formally angiotensin II receptor type 1 (AT1) antagonists, also known as angiotensin receptor blockers, angiotensin II receptor antagonists, or AT1 receptor antagonists, are a group of pharmaceuticals tha ...
s, nonsteroidal anti-inflammatory drugs, the antibiotic trimethoprim
Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for ''Pneumocystis'' pneumonia in peo ...
, and potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...
supplements), and at higher dosages of spironolactone.
Although spironolactone poses an important risk of hyperkalemia in the elderly, in those with kidney or cardiovascular disease, and/or in those taking medications or supplements which increase circulating potassium levels, a large retrospective study found that the rate of hyperkalemia in young women without such characteristics who had been treated with high doses of spironolactone for dermatological conditions did not differ from that of controls. This was the conclusion of a 2017 hybrid systematic review of studies of spironolactone for acne in women as well, which found that hyperkalemia was rare and was invariably mild and clinically insignificant. These findings suggest that hyperkalemia may not be a significant risk in such individuals, and that routine monitoring of circulating potassium levels may be unnecessary in this population. However, other sources have claimed that hyperkalemia can nonetheless also occur in people with more normal renal function and presumably without such risk factors. Occasional testing on a case-by-case basis in those with known risk factors may be justified. Side effects of spironolactone which may be indicative of hyperkalemia and if persistent could justify serum potassium testing include nausea, fatigue, and particularly muscle weakness. Notably, non-use of routine potassium monitoring with spironolactone in young women would reduce costs associated with its use.
Breast changes
Spironolactone frequently causes breast pain and breast enlargement Breast enlargement is the enlargement of the breasts. It may occur naturally as in mammoplasia or may occur artificially through active intervention. Many women regard their breasts, which are female secondary sex characteristics, as important to t ...
in women. This is "probably because of estrogenic effects on target tissue." At low doses, breast tenderness has been reported in only 5% of women, but at high doses, it has been reported in up to 40% of women. Breast enlargement and tenderness may occur in 26% of women at high doses. Some women regard spironolactone-induced breast enlargement as a positive effect.
Spironolactone also commonly and dose-dependently produces gynecomastia
Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse ( ...
(breast development) as a side effect in men. At low doses, the rate is only 5 to 10%, but at high doses, up to or exceeding 50% of men may develop gynecomastia. In the RALES, 9.1% of men taking 25 mg/day spironolactone developed gynecomastia, compared to 1.3% of controls. Conversely, in studies of healthy men given high-dose spironolactone, gynecomastia occurred in 3 of 10 (30%) at 100 mg/day, in 5 of 8 (62.5%) at 200 mg/day, and in 6 of 9 (66.7%) at 400 mg/day, relative to none of 12 controls. The severity of gynecomastia with spironolactone varies considerably, but is usually mild. As with breast enlargement caused by spironolactone in women, gynecomastia due to spironolactone in men is often although inconsistently accompanied by breast tenderness. In the RALES, only 1.7% of men developed breast pain, relative to 0.1% of controls.
The time to onset of spironolactone-induced gynecomastia has been found to be 27 ± 20 months at low doses and 9 ± 12 months at high doses. Gynecomastia induced by spironolactone usually regresses after a few weeks following discontinuation of the medication. However, after a sufficient duration of gynecomastia being present (e.g., one year), hyalinization and fibrosis
Fibrosis, also known as fibrotic scarring, is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of perma ...
of the tissue occurs and drug-induced gynecomastia may become irreversible.
Menstrual disturbances
Spironolactone at higher doses can cause menstrual irregularities
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia (vaginal bleeding between expected periods). The possible causes of irregular menstruation may vary. The common factors of ...
as a side effect in women. These irregularities include metrorrhagia
Intermenstrual bleeding, previously known as metrorrhagia, is uterine bleeding at irregular intervals, particularly between the expected menstrual periods. It is a cause of vaginal bleeding.
In some women, menstrual spotting between periods occu ...
(intermenstrual bleeding), amenorrhea
Amenorrhea is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding). Outside the reproductive years, there is absence of menses ...
(absence of menstruation), and breakthrough bleeding
Intermenstrual bleeding, previously known as metrorrhagia, is uterine bleeding at irregular intervals, particularly between the expected menstrual periods. It is a cause of vaginal bleeding.
In some women, menstrual spotting between periods occ ...
. They are common during spironolactone therapy, with 10 to 50% of women experiencing them at moderate doses and almost all experiencing them at a high doses. For example, about 20% of women experienced menstrual irregularities with 50 to 100 mg/day spironolactone, whereas about 70% experienced menstrual irregularities at 200 mg/day. Most women taking moderate doses of spironolactone develop amenorrhea, and normal menstruation usually returns within two months of discontinuation. Spironolactone produces an irregular and anovulatory
Anovulation is when the ovaries do not release an oocyte during a menstrual cycle. Therefore, ovulation does not take place. However, a woman who does not ovulate at each menstrual cycle is not necessarily going through menopause. Chronic anovula ...
pattern of menstrual cycles. It is also associated with metrorrhagia and menorrhagia (heavy menstrual bleeding) in large percentages of women, as well as with polymenorrhea
Polymenorrhea, also known as frequent periods, frequent menstruation, or frequent menstrual bleeding, is a menstrual disorder in which menstrual cycles are shorter than 21days in length and hence where menstruation occurs more frequently than us ...
(short menstrual cycles). The medication reportedly has no birth control effect.
It has been suggested that the weak progestogenic activity of spironolactone is responsible for these effects, although this has not been established and spironolactone has been shown to possess insignificant progestogenic and antiprogestogenic activity even at high dosages in women. An alternative proposed cause is inhibition of 17α-hydroxylase and hence sex steroid metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
by spironolactone and consequent changes in sex hormone levels. Indeed, CYP17A1
Cytochrome P450 17A1 (steroid 17α-monooxygenase, 17α-hydroxylase, 17-alpha-hydroxylase, 17,20-lyase, 17,20-desmolase) is an enzyme of the hydroxylase type that in humans is encoded by the ''CYP17A1'' gene on chromosome 10. It is ubiquitously exp ...
genotype is associated with polymenorrhea. Regardless of their mechanism, the menstrual disturbances associated with spironolactone can usually be controlled well by concomitant treatment with a birth control pill
The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: progesti ...
, due to the progestin component.
Mood changes
Research is mixed on whether antimineralocorticoids like spironolactone have positive or negative effects on mood. In any case, it is possible that spironolactone might have the capacity to increase the risk of depressive symptoms. However, a 2017 hybrid systematic review found that the incidence of depression in women treated with spironolactone for acne was less than 1%. Likewise, a 10-year observational study found that the incidence of depression in 196 transgender women taking high-dose spironolactone in combination with an estrogen was less than 1%.
Rare reactions
Aside from hyperkalemia, spironolactone may rarely cause adverse reactions such as anaphylaxis
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the foll ...
, kidney failure
Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...
, hepatitis
Hepatitis is inflammation of the liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes ( jaundice), poor appetite, vomiting, tiredness, abdominal ...
(two reported cases, neither serious), agranulocytosis, DRESS syndrome
Drug reaction with eosinophilia and systemic symptoms (DRESS), also termed drug-induced hypersensitivity syndrome (DIHS), is a rare reaction to certain medications. It involves primarily a widespread skin rash, fever, swollen lymph nodes, and c ...
, Stevens–Johnson syndrome
Stevens–Johnson syndrome (SJS) is a type of severe skin reaction. Together with toxic epidermal necrolysis (TEN) and Stevens–Johnson/toxic epidermal necrolysis (SJS/TEN), it forms a spectrum of disease, with SJS being less severe. Erythema ...
or toxic epidermal necrolysis
Toxic epidermal necrolysis (TEN) is a type of severe skin reaction. Together with Stevens–Johnson syndrome (SJS) it forms a spectrum of disease, with TEN being more severe. Early symptoms include fever and flu-like symptoms. A few days later ...
. Five cases of breast cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a r ...
in patients who took spironolactone for prolonged periods of time have been reported.
Spironolactone bodies
Long-term administration of spironolactone gives the histologic
Histology,
also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...
characteristic of "spironolactone bodies" in the adrenal cortex. Spironolactone bodies are eosinophilic
Eosinophilic (Greek suffix -phil-, meaning ''loves eosin'') is the staining of tissues, cells, or organelles after they have been washed with eosin, a dye.
Eosin is an acidic dye for staining cell cytoplasm, collagen, and muscle fibers. ''E ...
, round, concentrically laminated cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. ...
ic inclusions surrounded by clear halos in preparations stained with hematoxylin
Haematoxylin or hematoxylin (), also called natural black 1 or C.I. 75290, is a compound extracted from heartwood of the logwood tree ('' Haematoxylum campechianum'') with a chemical formula of . This naturally derived dye has been used as a ...
and eosin
Eosin is the name of several fluorescent acidic compounds which bind to and form salts with basic, or eosinophilic, compounds like proteins containing amino acid residues such as arginine and lysine, and stains them dark red or pink as a resul ...
.
Pregnancy and breastfeeding
In the United States, spironolactone is considered pregnancy category
The pregnancy category of a medication is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. It does ''not'' include any risks conferred by pharmaceutical agents or their ...
C meaning that it is unclear if it is safe for use during pregnancy.[ It is able to cross the ]placenta
The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mate ...
. Likewise, it has been found to be present in the breast milk of lactating mothers and, while the effects of spironolactone or its metabolites have not been extensively studied in breastfeeding infants, it is generally recommended that women also not take the medication while nursing
Nursing is a profession within the health care sector focused on the care of individuals, families, and communities so they may attain, maintain, or recover optimal health and quality of life. Nurses may be differentiated from other health ...
. However, only very small amounts of spironolactone and its metabolite canrenone enter breast milk, and the amount received by an infant during breastfeeding (<0.5% of the mother's dose) is considered to be insignificant.
A study found that spironolactone was not associated with teratogenicity in the offspring of rats. Because it is an antiandrogen, however, spironolactone could theoretically have the potential to cause feminization of male fetuses at sufficient doses. In accordance, a subsequent study found that partial feminization of the genitalia occurred in the male offspring of rats that received doses of spironolactone that were five times higher than those normally used in humans (200 mg/kg per day). Another study found permanent, dose-related reproductive tract abnormalities rat offspring of both sexes at lower doses (50 to 100 mg/kg per day).
In practice however, although experience is limited, spironolactone has never been reported to cause observable feminization or any other congenital defects in humans. Among 31 human newborns exposed to spironolactone in the first trimester, there were no signs of any specific birth defect
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities ca ...
s. A case report described a woman who was prescribed spironolactone during pregnancy with triplets and delivered all three (one boy and two girls) healthy; there was no feminization in the boy. In addition, spironolactone has been used at high doses to treat pregnant women with Bartter's syndrome, and none of the infants (three boys, two girls) showed toxicity, including feminization in the male infants. There are similar findings, albeit also limited, for another antiandrogen, cyproterone acetate (prominent genital defects in male rats, but no human abnormalities (including feminization of male fetuses) at both a low dose of 2 mg/day or high doses of 50 to 100 mg/day). In any case, spironolactone is nonetheless not recommended during pregnancy due to theoretical concerns relating to feminization of males and also to potential alteration of fetal potassium levels.
A 2019 systematic review found insufficient evidence that spironolactone causes birth defects in humans. However, there was also insufficient evidence to be certain that it does not.
Overdose
Spironolactone is relatively safe in acute overdose
A drug overdose (overdose or OD) is the ingestion or application of a drug or other substance in quantities much greater than are recommended. . Symptoms following an acute overdose of spironolactone may include drowsiness
Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...
, confusion
In medicine, confusion is the quality or state of being bewildered or unclear. The term "acute mental confusion" , maculopapular
A maculopapular rash is a type of rash characterized by a flat, red area on the skin that is covered with small confluent bumps. It may only appear red in lighter-skinned people. The term "maculopapular" is a compound: '' macules'' are small, flat ...
or erythematous rash, nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
, vomiting
Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Vomiting can be the result of ailments like food poisoning, gastroenteri ...
, dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness.
Dizziness is a common medical c ...
, and diarrhea
Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
. In rare cases, hyponatremia
Hyponatremia or hyponatraemia is a low concentration of sodium in the blood. It is generally defined as a sodium concentration of less than 135 mmol/L (135 mEq/L), with severe hyponatremia being below 120 mEq/L. Symptoms can be a ...
, hyperkalemia
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasi ...
, or hepatic coma may occur in individuals with severe liver disease. However, these adverse reactions are unlikely in the event of an acute overdose. Hyperkalemia can occur following an overdose of spironolactone, and this is especially so in people with decreased kidney function. Spironolactone has been studied at extremely high oral doses of up to 2,400 mg per day in clinical trial
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, diet ...
s. Its oral median lethal dose (LD50) is more than 1,000 mg/kg in mice, rats, and rabbits.
There is no specific antidote
An antidote is a substance that can counteract a form of poisoning. The term ultimately derives from the Greek term φάρμακον ἀντίδοτον ''(pharmakon) antidoton'', "(medicine) given as a remedy". Antidotes for anticoagulants are s ...
for overdose of spironolactone. Treatment may consist of induction of vomiting
Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Vomiting can be the result of ailments like food poisoning, gastroenteri ...
or stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
evacuation by gastric lavage
Gastric lavage, also commonly called stomach pumping or gastric irrigation, is the process of cleaning out the contents of the stomach. Since its first recorded use in early 19th century, it has become one of the most routine means of eliminating ...
. The treatment of spironolactone overdose is supportive, with the purpose of maintaining hydration Hydration may refer to:
* Hydrate, a substance that contains water
* Hydration enthalpy, energy released through hydrating a substance
* Hydration reaction, a chemical addition reaction where a hydroxyl group and proton are added to a compound
* ...
, electrolyte balance, and vital function
Vital signs (also known as vitals) are a group of the four to six most crucial medical signs that indicate the status of the body's vital (life-sustaining) functions. These measurements are taken to help assess the general physical health of a p ...
s. Spironolactone should be discontinued in people with impaired kidney function or hyperkalemia.
Interactions
Spironolactone often increases serum potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...
levels and can cause hyperkalemia
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasi ...
, a very serious condition. Therefore, it is recommended that people using this medication avoid potassium supplements and salt substitutes containing potassium. Physicians must be careful to monitor potassium levels in both males and females who are taking spironolactone as a diuretic, especially during the first twelve months of use and whenever the dosage is increased. Doctors may also recommend that some patients may be advised to limit dietary consumption of potassium-rich foods. However, recent data suggests that both potassium monitoring and dietary restriction of potassium intake is unnecessary in healthy young women taking spironolactone for acne. Spironolactone together with trimethoprim/sulfamethoxazole
Trimethoprim/sulfamethoxazole, sold under the brand name Bactrim among others, is a fixed-dose combination antibiotic medication used to treat a variety of bacterial infections. It consists of one part trimethoprim to five parts sulfamethoxa ...
increases the likelihood of hyperkalemia, especially in the elderly. The trimethoprim portion acts to prevent potassium excretion in the distal tubule of the nephron.
Spironolactone has been reported to induce the enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
s CYP3A4 and certain UDP-glucuronosyltransferase
Uridine 5'-diphospho-glucuronosyltransferase ( UDP-glucuronosyltransferase, UGT) is a microsomal glycosyltransferase () that catalyzes the transfer of the glucuronic acid component of UDP-glucuronic acid to a small hydrophobic molecule. This is ...
s (UGTs), which can result in interaction
Interaction is action that occurs between two or more objects, with broad use in philosophy and the sciences. It may refer to:
Science
* Interaction hypothesis, a theory of second language acquisition
* Interaction (statistics)
* Interactions o ...
s with various medications. However, it has also been reported that metabolites of spironolactone irreversibly inhibit CYP3A4. In any case, spironolactone has been found to reduce the bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation.
By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...
of oral estradiol
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...
, which could be due to induction of estradiol metabolism via CYP3A4. Spironolactone has also been found to inhibit
Inhibitor or inhibition may refer to:
In biology
* Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity
* Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotr ...
UGT2B7
UGT2B7 (UDP-Glucuronosyltransferase-2B7) is a phase II metabolism isoenzyme found to be active in the liver, kidneys, epithelial cells of the lower gastrointestinal tract and also has been reported in the brain. In humans, UDP-Glucuronosyltrans ...
. Spironolactone can also have numerous other interactions, most commonly with other cardiac
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...
and blood pressure medications, for instance digoxin.
Licorice
Liquorice (British English) or licorice (American English) ( ; also ) is the common name of ''Glycyrrhiza glabra'', a flowering plant of the bean family Fabaceae, from the root of which a sweet, aromatic flavouring can be extracted.
The liq ...
, which has indirect mineralocorticoid activity by inhibiting mineralocorticoid metabolism, has been found to inhibit the antimineralocorticoid effects of spironolactone. Moreover, the addition of licorice to spironolactone has been found to reduce the antimineralocorticoid side effects of spironolactone in women treated with it for hyperandrogenism, and licorice hence may be used to reduce these side effects in women treated with spironolactone as an antiandrogen who are bothered by them. On the opposite end of the spectrum, spironolactone is useful in reversing licorice-induced hypokalemia
Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an abno ...
. Aspirin
Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...
and other nonsteroidal anti-inflammatory drugs (NSAIDs) have been found to attenuate the diuresis
Diuresis () is increased urination (polyuria) or, in the related word senses more often intended, the physiological process that produces such an increase or the administration of medications to encourage that process. It involves extra urine pr ...
and natriuresis Natriuresis is the process of sodium excretion in the urine through the action of the kidneys. It is promoted by ventricular and atrial natriuretic peptides as well as calcitonin, and inhibited by chemicals such as aldosterone. Natriuresis lowers t ...
induced by spironolactone, but, not to affect its antihypertensive effect.
Some research has suggested that spironolactone might be able to interfere with the effectiveness of antidepressant treatment. As the medication acts as an antimineralocorticoid, it is thought that it might be able to reduce the effectiveness of certain antidepressants by interfering with normalization of the hypothalamic–pituitary–adrenal axis
The hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis) is a complex set of direct influences and feedback interactions among three components: the hypothalamus (a part of the brain located below the thalamus), the pituitary gland (a ...
and by increasing levels of glucocorticoid
Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every verteb ...
s such as cortisol.[Holsboer, F. The Rationale for Corticotropin-Releasing Hormone Receptor (CRH-R) Antagonists to Treat Depression and Anxiety. J. Psychiatr. Res. 33, 181–214 (1999).] However, other research contradicts this hypothesis and has suggested that spironolactone might actually produce antidepressant effects, for instance studies showing antidepressant-like effects of spironolactone in animals.
Pharmacology
Pharmacodynamics
The pharmacodynamics
Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or combinations of organisms ...
of spironolactone are characterized by high antimineralocorticoid
An antimineralocorticoid, also known as a mineralocorticoid receptor antagonist (MRA or MCRA) or aldosterone antagonist, is a diuretic drug which antagonizes the action of aldosterone at mineralocorticoid receptors. This group of drugs is ofte ...
activity, moderate antiandrogen
Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the ...
ic activity, and weak steroidogenesis inhibition, among other more minor activities. Spironolactone is a prodrug, so most of its actions are actually mediated by its various active metabolite An active metabolite is an active form of a drug after it has been processed by the body.
Metabolites of drugs
An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body ...
s. The major active forms of spironolactone are 7α-thiomethylspironolactone
7α-Thiomethylspironolactone (7α-TMS; developmental code name SC-26519) is a steroidal antimineralocorticoid and antiandrogen of the spirolactone group and the major active metabolite of spironolactone. Other important metabolites of spironola ...
(7α-TMS) and canrenone
Canrenone, sold under the brand names Contaren, Luvion, Phanurane, and Spiroletan, is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone which is used as a diuretic in Europe, including in Italy and Belgium. It ...
(7α-desthioacetyl-δ6-spironolactone).
Spironolactone is a potent antimineralocorticoid. That is, it is an antagonist of the mineralocorticoid receptor
The mineralocorticoid receptor (or MR, MLR, MCR), also known as the aldosterone receptor or nuclear receptor subfamily 3, group C, member 2, (NR3C2) is a protein that in humans is encoded by the ''NR3C2'' gene that is located on chromosome 4q31 ...
(MR), the biological target
A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets ...
of mineralocorticoid
Mineralocorticoids are a class of corticosteroids, which in turn are a class of steroid hormones. Mineralocorticoids are produced in the adrenal cortex and influence salt and water balances ( electrolyte balance and fluid balance). The primary ...
s like aldosterone and 11-deoxycorticosterone
11-Deoxycorticosterone (DOC), or simply deoxycorticosterone, also known as 21-hydroxyprogesterone, as well as desoxycortone (INN), deoxycortone, and cortexone, is a steroid hormone produced by the adrenal gland that possesses mineralocorticoid ac ...
. By blocking the MR, spironolactone inhibits the effects of mineralocorticoids in the body. The antimineralocorticoid activity of spironolactone is responsible for its therapeutic efficacy in the treatment of edema, high blood pressure, heart failure, hyperaldosteronism, and ascites
Ascites is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdominal size, increased weight, a ...
due to cirrhosis
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage causes tissue rep ...
. It is also responsible for many of the side effects of spironolactone, such as urinary frequency
Frequent urination, or urinary frequency (sometimes called pollakiuria), is the need to urinate more often than usual. Diuretics are medications that increase urinary frequency. Nocturia is the need of frequent urination at night. The most common c ...
, dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
, hyponatremia
Hyponatremia or hyponatraemia is a low concentration of sodium in the blood. It is generally defined as a sodium concentration of less than 135 mmol/L (135 mEq/L), with severe hyponatremia being below 120 mEq/L. Symptoms can be a ...
, low blood pressure
Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the di ...
, fatigue, dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness.
Dizziness is a common medical c ...
, metabolic acidosis
Metabolic acidosis is a serious electrolyte disorder characterized by an imbalance in the body's acid-base balance. Metabolic acidosis has three main root causes: increased acid production, loss of bicarbonate, and a reduced ability of the kidneys ...
, decreased kidney function
Assessment of kidney function occurs in different ways, using the presence of symptoms and signs, as well as measurements using urine tests, blood tests, and medical imaging.
Functions of a healthy kidney include maintaining a person's fluid ...
, and its risk of hyperkalemia
Hyperkalemia is an elevated level of potassium (K+) in the blood. Normal potassium levels are between 3.5 and 5.0mmol/L (3.5 and 5.0mEq/L) with levels above 5.5mmol/L defined as hyperkalemia. Typically hyperkalemia does not cause symptoms. Occasi ...
. Due to the antimineralocorticoid activity of spironolactone, levels of aldosterone are significantly increased by the medication, probably reflecting an attempt of the body to maintain homeostasis
In biology, homeostasis (British also homoeostasis) (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and ...
.
Spironolactone is a moderate antiandrogen. That is, it is an antagonist of the androgen receptor (AR), the biological target of androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...
s like testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...
and dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues includ ...
(DHT). By blocking the AR, spironolactone inhibits the effects of androgens in the body. The antiandrogenic activity of spironolactone is mainly responsible for its therapeutic efficacy in the treatment of androgen-dependent skin and hair conditions like acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...
, seborrhea
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest numbe ...
, hirsutism
Hirsutism is excessive body hair on parts of the body where hair is normally absent or minimal. The word is from early 17th century: from Latin ''hirsutus'' meaning "hairy". It usually refers to a "male" pattern of hair growth in a female that ...
, and pattern hair loss
Pattern hair loss (also known as androgenetic alopecia (AGA)) is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front ...
and hyperandrogenism
Hyperandrogenism is a medical condition characterized by high levels of androgens. It is more common in women than men. Symptoms of hyperandrogenism may include acne, seborrhea (inflamed skin), hair loss on the scalp, increased body or facia ...
in women, precocious puberty
In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. In a minority of childr ...
in boys with testotoxicosis, and as a component of feminizing hormone therapy
Feminizing hormone therapy, also known as transfeminine hormone therapy, is hormone therapy and sex reassignment therapy to change the secondary sex characteristics of transgender people from masculine or androgynous to feminine. It is a co ...
for transgender women
A trans woman or a transgender woman is a woman who was assigned male at birth. Trans women have a female gender identity, may experience gender dysphoria, and may transition; this process commonly includes hormone replacement therapy and ...
. It is also primarily responsible for some of its side effects, like breast tenderness
Breast pain is the symptom of discomfort in either one or both breasts. Pain in both breasts is often described as ''breast tenderness'', is usually associated with the menstrual period and is not serious. Pain that involves only one part of a br ...
, gynecomastia
Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse ( ...
, feminization
Feminization most commonly refers to:
* Feminization (biology), the hormonally induced development of female sexual characteristics
* Feminization (activity), a sexual or lifestyle practice where a person assumes a female role
* Feminization (soci ...
, and demasculinization
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens.
Virilization is most commonly used in three medical and biology ...
in men. Blockade of androgen signaling in the breast
The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues.
In females, it serves as the mammary gland, which produces and sec ...
disinhibits the actions of estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
s in this tissue. Although useful as an antiandrogen in women, who have low testosterone levels compared to men, spironolactone is described as having relatively weak antiandrogenic activity.
Spironolactone is a weak steroidogenesis inhibitor. That is, it inhibits steroidogenic enzyme __NOTOC__
Steroidogenic enzymes are enzymes that are involved in steroidogenesis and steroid biosynthesis. They are responsible for the biosynthesis of the steroid hormones, including sex steroids (androgens, estrogens, and progestogens) and cortic ...
s, or enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
s involved in the production of steroid hormones. Spironolactone and/or its metabolites have been found ''in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called " test-tube experiments", these studies in biology ...
'' to weakly inhibit
Inhibitor or inhibition may refer to:
In biology
* Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity
* Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotr ...
a broad array of steroidogenic enzymes including cholesterol side-chain cleavage enzyme
Cholesterol side-chain cleavage enzyme is commonly referred to as P450scc, where "scc" is an acronym for side-chain cleavage. P450scc is a mitochondrial enzyme that catalyzes conversion of cholesterol to pregnenolone. This is the first reactio ...
, 17α-hydroxylase
Cytochrome P450 17A1 (steroid 17α-monooxygenase, 17α-hydroxylase, 17-alpha-hydroxylase, 17,20-lyase, 17,20-desmolase) is an enzyme of the hydroxylase type that in humans is encoded by the ''CYP17A1'' gene on chromosome 10. It is ubiquitously exp ...
, 17,20-lyase
Cytochrome P450 17A1 (steroid 17α-monooxygenase, 17α-hydroxylase, 17-alpha-hydroxylase, 17,20-lyase, 17,20-desmolase) is an enzyme of the hydroxylase type that in humans is encoded by the ''CYP17A1'' gene on chromosome 10. It is ubiquitously exp ...
, 5α-reductase, 3β-hydroxysteroid dehydrogenase, 11β-hydroxylase, 21-hydroxylase
Steroid 21-hydroxylase (also known as steroid 21-monooxygenase, cytochrome P450C21, 21α-hydroxylase and less commonly 21β-hydroxylase) is an enzyme that hydroxylates steroids at the C21 position and is involved in biosynthesis of aldosterone a ...
, and aldosterone synthase
Aldosterone synthase, also called steroid 18-hydroxylase, corticosterone 18-monooxygenase or P450C18, is a steroid hydroxylase cytochrome P450 enzyme involved in the biosynthesis of the mineralocorticoid aldosterone and other steroids. The enzyme ...
(18-hydroxylase). However, although very high doses of spironolactone can considerably decrease steroid hormone levels in animals, spironolactone has shown mixed and inconsistent effects on steroid hormone levels in clinical studies, even at high clinical doses. In any case, the levels of most steroid hormones, including testosterone and cortisol, are usually unchanged by spironolactone in humans, which may in part be related to compensatory upregulation of their synthesis. The weak steroidogenesis inhibition of spironolactone might contribute to its antiandrogenic efficacy to some degree and may explain its side effect of menstrual irregularities in women. However, its androgen synthesis inhibition is probably clinically insignificant.
Spironolactone has been found in some studies to increase levels of estradiol
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...
, an estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
, although many other studies have found no changes in estradiol levels. The mechanism of how spironolactone increases estradiol levels is unclear, but it may involve inhibition of the inactivation of estradiol into estrone
Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized ...
and enhancement of the peripheral conversion of testosterone into estradiol. It is notable that spironolactone has been found ''in vitro'' to act as a weak inhibitor of 17β-hydroxysteroid dehydrogenase 2, an enzyme that is involved in the conversion of estradiol into estrone. Increased levels of estradiol with spironolactone may be involved in its preservation of bone density
Bone density, or bone mineral density, is the amount of bone mineral in bone tissue. The concept is of mass of mineral per volume of bone (relating to density in the physics sense), although clinically it is measured by proxy according to optic ...
and in its side effects such as breast tenderness, breast enlargement, and gynecomastia in women and men.
In response to the antimineralocorticoid activity spironolactone, and in an attempt to maintain homeostasis
In biology, homeostasis (British also homoeostasis) (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and ...
, the body increases aldosterone production in the adrenal cortex. Some studies have found that levels of cortisol, a glucocorticoid
Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every verteb ...
hormone that is also produced in the adrenal cortex, are increased as well. However, other clinical studies have found no change in cortisol levels with spironolactone, and those that have found increases often have observed only small changes. In accordance, spironolactone has not been associated with conventional glucocorticoid medication effects or side effects.
Other activities of spironolactone may include very weak interactions with the estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
and progesterone receptors and agonism of the pregnane X receptor
In the field of molecular biology, the pregnane X receptor (PXR), also known as the steroid and xenobiotic sensing nuclear receptor (SXR) or nuclear receptor subfamily 1, group I, member 2 (NR1I2) is a protein that in humans is encoded by the ' ...
. These activities could contribute to the menstrual irregularities
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia (vaginal bleeding between expected periods). The possible causes of irregular menstruation may vary. The common factors of ...
and breast
The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues.
In females, it serves as the mammary gland, which produces and sec ...
side effects of spironolactone and to its drug interaction
Drug interactions occur when a drug's mechanism of action is disturbed by the concomitant administration of substances such as foods, beverages, or other drugs. The cause is often the inhibition of the specific receptors available to the drug, ...
s, respectively.
Pharmacokinetics
The pharmacokinetics of spironolactone have not been studied well, which is in part because it is an old medication that was developed in the 1950s. Nonetheless, much has been elucidated about the pharmacokinetics of spironolactone over the decades.
Absorption
The bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation.
By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...
of spironolactone when taken by mouth
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...
is 60 to 90%. The bioavailability of spironolactone and its metabolites increases significantly (+22–95% increases in levels) when spironolactone is taken with food, although it is uncertain whether this further increases the therapeutic effects of the medication. The increase in bioavailability is thought to be due to promotion of the gastric dissolution and absorption of spironolactone, as well as due to a decrease of the first-pass metabolism
The first pass effect (also known as first-pass metabolism or presystemic metabolism) is a phenomenon of drug metabolism whereby the concentration of a drug, specifically when administered orally, is greatly reduced before it reaches the system ...
. The relationship between a single dose of spironolactone and plasma levels of canrenone
Canrenone, sold under the brand names Contaren, Luvion, Phanurane, and Spiroletan, is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone which is used as a diuretic in Europe, including in Italy and Belgium. It ...
, a major active metabolite An active metabolite is an active form of a drug after it has been processed by the body.
Metabolites of drugs
An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body ...
of spironolactone, has been found to be linear across a dose range of 25 to 200 mg spironolactone. Steady-state concentrations of spironolactone are achieved within 8 to 10 days of treatment initiation.
Little or no systemic absorption has been observed with topical spironolactone.
Distribution
Spironolactone and its metabolite canrenone are highly plasma protein bound, with percentages of 88.0% and 99.2%, respectively. Spironolactone is bound equivalently to albumin
Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins ...
and α1-acid glycoprotein, while canrenone is bound only to albumin. Spironolactone and its metabolite 7α-thiospironolactone
7α-Thiospironolactone (7α-TS; developmental code name SC-24813; also known as deacetylspironolactone) is a steroidal antimineralocorticoid and antiandrogen of the spirolactone group and a minor active metabolite of spironolactone. Other import ...
show very low or negligible affinity for sex hormone-binding globulin
Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. When produced by the Sertoli cells in the seminiferous tubules of the testis, it has also been called androgen ...
(SHBG). In accordance, a study of high-dosage spironolactone treatment found no change in steroid binding capacity related to SHBG or to corticosteroid-binding globulin
Transcortin, also known as corticosteroid-binding globulin (CBG) or serpin A6, is a protein produced in the liver in animals. In humans it is encoded by the SERPINA6 gene. It is an alpha-globulin.
Function
This gene encodes an alpha-globulin p ...
(CBG), suggesting that spironolactone does not displace steroid hormone
A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence ''cortico-'') and sex steroids (typically made in the gonads or placenta). Withi ...
s from their carrier protein
A membrane transport protein (or simply transporter) is a membrane protein involved in the movement of ions, small molecules, and macromolecules, such as another protein, across a biological membrane. Transport proteins are integral transmembrane ...
s. This is in contradiction with widespread statements that spironolactone increases free estradiol levels by displacing estradiol from SHBG.
Spironolactone appears to cross the blood–brain barrier.
Metabolism
Spironolactone is rapidly and extensively metabolized
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
in the liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...
upon oral administration
Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are ...
and has a very short terminal half-life
Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...
of 1.4 hours. The major metabolites of spironolactone are 7α-thiomethylspironolactone
7α-Thiomethylspironolactone (7α-TMS; developmental code name SC-26519) is a steroidal antimineralocorticoid and antiandrogen of the spirolactone group and the major active metabolite of spironolactone. Other important metabolites of spironola ...
(7α-TMS), 6β-hydroxy-7α-thiomethylspironolactone (6β-OH-7α-TMS), and canrenone
Canrenone, sold under the brand names Contaren, Luvion, Phanurane, and Spiroletan, is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone which is used as a diuretic in Europe, including in Italy and Belgium. It ...
(7α-desthioacetyl-δ6-spironolactone). These metabolites have much longer elimination half-lives than spironolactone of 13.8 hours, 15.0 hours, and 16.5 hours, respectively, and are responsible for the therapeutic effects of the medication. As such, spironolactone is a prodrug. The 7α-thiomethylated metabolites of spironolactone were not known for many years and it was originally thought that canrenone was the major active metabolite of the medication, but subsequent research identified 7α-TMS as the major metabolite. Other known but more minor metabolites of spironolactone include 7α-thiospironolactone
7α-Thiospironolactone (7α-TS; developmental code name SC-24813; also known as deacetylspironolactone) is a steroidal antimineralocorticoid and antiandrogen of the spirolactone group and a minor active metabolite of spironolactone. Other import ...
(7α-TS), which is an important intermediate to the major metabolites of spironolactone, as well as the 7α-methyl ethyl ester of spironolactone and the 6β-hydroxy-7α-methyl ethyl ester of spironolactone.
Spironolactone is hydrolyzed or deacetylated at the thioester
In organic chemistry, thioesters are organosulfur compounds with the functional group . They are analogous to carboxylate esters () with the sulfur in the thioester playing the role of the linking oxygen in the carboxylate ester, as implied by t ...
of the C7α position into 7α-TS by carboxylesterase
The enzyme carboxylesterase (or carboxylic-ester hydrolase, EC 3.1.1.1; systematic name carboxylic-ester hydrolase) catalyzes reactions of the following form:
:a carboxylic ester + H2O \rightleftharpoons an alcohol + a carboxylate
Most enzymes fr ...
s. Following formation of 7α-TS, it is ''S''- oxygenated by flavin-containing monooxygenase
The flavin-containing monooxygenase (FMO) protein family specializes in the oxidation of xeno-substrates in order to facilitate the excretion of these compounds from living organisms. These enzymes can oxidize a wide array of heteroatoms, par ...
s to form an electrophilic sulfenic acid metabolite. This metabolite is involved in the CYP450 inhibition of spironolactone, and also binds covalently
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atom ...
to other protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
s. 7α-TS is also ''S''-methylated
In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These ...
into 7α-TMS, a transformation catalyzed by thiol ''S''-methyltransferase. Unlike the related medication eplerenone
Eplerenone, sold under the brand name Inspra, is an aldosterone antagonist type of potassium-sparing diuretic that is used to treat chronic heart failure and high blood pressure, particularly for patients with resistant hypertension due to ele ...
, spironolactone is said to not be metabolized by CYP3A4. However, hepatic CYP3A4 is likely responsible for the 6β- hydroxylation of 7α-TMS into 6β-OH-7α-TMS. 7α-TMS may also be hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydro ...
ated at the C3α and C3β positions. Spironolactone is dethioacetylated into canrenone. Finally, the C17 γ-lactone
Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring.
Lactones are formed by intramolecular esterification of the co ...
ring
Ring may refer to:
* Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry
* To make a sound with a bell, and the sound made by a bell
:(hence) to initiate a telephone connection
Arts, entertainment and media Film and ...
of spironolactone is hydrolyzed by the paraoxonase
Paraoxonases are a family of mammalian enzymes with aryldialkylphosphatase activity. There are three paraoxonase isozymes, which were originally discovered for their involvement in the hydrolysis of organophosphates.
Research has indicated the ...
PON3
Paraoxonase 3, also known as PON3, is a protein which in humans is encoded by the ''PON3'' gene.
Function
This gene is a member of the paraoxonase family and lies in a cluster on chromosome 7 with the other two family members. The encoded prote ...
. It was originally thought to be hydrolyzed by PON1, but this was due to contamination with PON3.
Elimination
The majority of spironolactone is eliminated by the kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
s, while minimal amounts are handled by biliary
A bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates.
Bile is required for the digestion of food and is secreted by the liver into passages that carry bile toward the hepatic duct. It ...
excretion.
Chemistry
Spironolactone, also known as ''7α-acetylthiospirolactone'', is a steroidal 17α-spirolactone
Spirolactones are a class of functional group in organic chemistry featuring a cyclic ester attached spiro to another ring system. The name is also used to refer to a class of synthetic steroids, called steroid-17α-spirolactones, 17α-spiro ...
, or more simply a spirolactone. It can most appropriately be conceptualized as a derivative
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...
of progesterone, itself also a potent antimineralocorticoid, in which a hydroxyl group has been substituted at the C17α position (as in 17α-hydroxyprogesterone
17α-Hydroxyprogesterone (17α-OHP), also known as 17-OH progesterone (17-OHP), or hydroxyprogesterone (OHP), is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many o ...
), the acetyl group at the C17β position has been cyclized with the C17α hydroxyl group to form a spiro 21- carboxylic acid γ-lactone
Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring.
Lactones are formed by intramolecular esterification of the co ...
ring
Ring may refer to:
* Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry
* To make a sound with a bell, and the sound made by a bell
:(hence) to initiate a telephone connection
Arts, entertainment and media Film and ...
, and an acetyl thio group has been substituted in at the C7α position. These structural modifications of progesterone confer increased oral
The word oral may refer to:
Relating to the mouth
* Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid
**Oral administration of medicines
** Oral examination (also known as an oral exam or or ...
bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation.
By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...
and potency
Potency may refer to:
* Potency (pharmacology), a measure of the activity of a drug in a biological system
* Virility
* Cell potency, a measure of the differentiation potential of stem cells
* In homeopathic dilutions, potency is a measure of how ...
, potent antiandrogenic activity, and strongly reduced progestogenic activity. The C7α substitution is likely responsible for or involved in the antiandrogenic activity of spironolactone, as 7α-thioprogesterone (SC-8365), unlike progesterone, is an antiandrogen with similar affinity to the AR as that of spironolactone. In addition, the C7α substitution appears to be responsible for the loss of progestogenic activity and good oral bioavailability of spironolactone, as SC-5233
SC-5233, also known as 6,7-dihydrocanrenone or 20-spirox-4-ene-3,20-dione, is a synthetic, steroidal antimineralocorticoid of the spirolactone group which was developed by G. D. Searle & Company in the 1950s but was never marketed. It was the fi ...
, the analogue of spironolactone without a C7α substitution, has potent progestogenic activity but very poor oral bioavailability similarly to progesterone.
Names
Spironolactone is also known by the following equivalent chemical names:
* 7α-Acetylthio-17α-hydroxy-3-oxopregn-4-ene-21-carboxylic acid γ-lactone
* 7α-Acetylthio-3-oxo-17α-pregn-4-ene-21,17β-carbolactone
* 3-(3-Oxo-7α-acetylthio-17β-hydroxyandrost-4-en-17α-yl)propionic acid lactone
* 7α-Acetylthio-17α-(2-carboxyethyl)androst-4-en-17β-ol-3-one γ-lactone
* 7α-Acetylthio-17α-(2-carboxyethyl)testosterone γ-lactone
Analogues
Spironolactone is closely related structurally to other clinically used spirolactones such as canrenone
Canrenone, sold under the brand names Contaren, Luvion, Phanurane, and Spiroletan, is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone which is used as a diuretic in Europe, including in Italy and Belgium. It ...
, potassium canrenoate
Potassium canrenoate ( INN, JAN) or canrenoate potassium (USAN) (brand names Venactone, Soldactone), also known as aldadiene kalium, the potassium salt of canrenoic acid, is an aldosterone antagonist of the spirolactone group. Like spironolact ...
, drospirenone
Drospirenone is a progestin and antiandrogen medication which is used in birth control pills to prevent pregnancy and in menopausal hormone therapy, among other uses. It is available both alone under the brand name Slynd and in combination wi ...
, and eplerenone
Eplerenone, sold under the brand name Inspra, is an aldosterone antagonist type of potassium-sparing diuretic that is used to treat chronic heart failure and high blood pressure, particularly for patients with resistant hypertension due to ele ...
, as well as to the never-marketed spirolactones SC-5233
SC-5233, also known as 6,7-dihydrocanrenone or 20-spirox-4-ene-3,20-dione, is a synthetic, steroidal antimineralocorticoid of the spirolactone group which was developed by G. D. Searle & Company in the 1950s but was never marketed. It was the fi ...
(6,7-dihydrocanrenone; 7α-desthioacetylspironolactone), SC-8109
SC-8109 is a steroidal antimineralocorticoid of the spirolactone group which was never marketed. It is a potent antagonist of the mineralocorticoid receptor and is more potent than the related drug SC-5233 (of which SC-8109 is the 19-nor analog ...
(19-nor-6,7-dihydrocanrenone), spiroxasone
Spiroxasone (, ) is a synthetic, steroidal antimineralocorticoid of the spirolactone group which was developed as a diuretic and antihypertensive agent but was never marketed. It was synthesized and assayed in 1963. The drug is 7α-acetylthi ...
, prorenone
Prorenone (developmental code name SC-23133) is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone that was never marketed. It is the lactonic form of prorenoic acid (prorenoate), and prorenoate potassium (S ...
(SC-23133), mexrenone
Mexrenone (code names ZK-32055, SC-25152) is a steroidal antimineralocorticoid of the spirolactone group related to spironolactone that was never marketed. It is the lactonic form of mexrenoic acid (mexrenoate), and mexrenoate potassium (SC-2 ...
(SC-25152, ZK-32055), dicirenone
Dicirenone (International Nonproprietary Name, INN, United States Adopted Name, USAN; developmental code name SC-26304; also known as 7α-carboxyisopropylspirolactone) is a synthetic compound, synthetic, steroidal antimineralocorticoid of the spi ...
(SC-26304), spirorenone
Spirorenone (INN) (developmental code name ZK-35973) is a steroidal antimineralocorticoid of the spirolactone group that was never marketed. Spirorenone possesses 5–8 times the antimineralocorticoid activity of spironolactone in animal studies ...
(ZK-35973), and mespirenone (ZK-94679).
Synthesis
Chemical syntheses of spironolactone and its analogues and derivative
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...
s have been described and reviewed.
History
The natriuretic Natriuresis is the process of sodium excretion in the urine through the action of the kidneys. It is promoted by ventricular and atrial natriuretic peptides as well as calcitonin, and inhibited by chemicals such as aldosterone. Natriuresis lowers ...
effects of progesterone were demonstrated in 1955, and the development of spironolactone as a synthetic antimineralocorticoid analogue of progesterone shortly followed this. Spironolactone was first synthesized in 1957, was patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...
ed between 1958 and 1961, and was first marketed, as an antimineralocorticoid, in 1959. Gynecomastia was first reported with spironolactone in 1962, and the antiandrogenic activity of the medication was first described in 1969. This shortly followed the discovery in 1967 that gynecomastia is an important and major side effect of AR antagonists. Spironolactone was first studied in the treatment of hirsutism in women in 1978. It has since become the most widely used antiandrogen for dermatological indications in women in the United States. Spironolactone was first studied as an antiandrogen in transgender women in 1986, and has since become widely adopted for this purpose as well, particularly in the United States where cyproterone acetate is not available.
Early oral spironolactone tablets showed poor absorption. The formulation was eventually changed to a micronized
Micronization is the process of reducing the average diameter of a solid material's particles. Traditional techniques for micronization focus on mechanical means, such as milling and grinding. Modern techniques make use of the properties of superc ...
formulation with particle size
Particle size is a notion introduced for comparing dimensions of solid particles ('' flecks''), liquid particles ('' droplets''), or gaseous particles ('' bubbles''). The notion of particle size applies to particles in colloids, in ecology, in ...
s of less than 50 μg, which resulted in approximately 4-fold increased potency.
Society and culture
Generic names
The English, French, and generic name of the medication is ''spironolactone'' and this is its , , , , , and . Its name is ''spironolactonum'' in Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
, ''spironolacton'' in German
German(s) may refer to:
* Germany (of or related to)
** Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
, ''espironolactona'' in Spanish
Spanish might refer to:
* Items from or related to Spain:
**Spaniards are a nation and ethnic group indigenous to Spain
**Spanish language, spoken in Spain and many Latin American countries
**Spanish cuisine
Other places
* Spanish, Ontario, Can ...
and Portuguese
Portuguese may refer to:
* anything of, from, or related to the country and nation of Portugal
** Portuguese cuisine, traditional foods
** Portuguese language, a Romance language
*** Portuguese dialects, variants of the Portuguese language
** Portu ...
, and ''spironolattone'' in Italian
Italian(s) may refer to:
* Anything of, from, or related to the people of Italy over the centuries
** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom
** Italian language, a Romance language
*** Regional Ita ...
(which is also its ).
Spironolactone is also known by its developmental code names ''SC-9420'' and ''NSC-150339''.
Brand names
Spironolactone is marketed under a large number of brand names throughout the world. The major brand name of spironolactone is Aldactone. Other important brand names include Aldactone-A, Berlactone, CaroSpir, Espironolactona, Espironolactona Genfar, Novo-Spiroton, Prilactone (veterinary
Veterinary medicine is the branch of medicine that deals with the prevention, management, diagnosis, and treatment of disease, disorder, and injury in animals. Along with this, it deals with animal rearing, husbandry, breeding, research on nutri ...
), Spiractin, Spiridon, Spirix, Spiroctan, Spiroderm (discontinued), Spirogamma, Spirohexal, Spirolon, Spirolone, Spiron, Spironolactone Actavis, Spironolactone Orion, Spironolactone Teva, Spirotone, Tempora (veterinary), Uractone, Uractonum, Verospiron, and Vivitar.
Spironolactone is also formulated in combination with a variety of other medications, including with hydrochlorothiazide
Hydrochlorothiazide is a diuretic medication often used to treat high blood pressure and swelling due to fluid build-up. Other uses include treating diabetes insipidus and renal tubular acidosis and to decrease the risk of kidney stones in ...
as Aldactazide, with hydroflumethiazide
Hydroflumethiazide (or Saluron) is a diuretic. Synthesis
See also
*Bendroflumethiazide
Bendroflumethiazide, formerly bendrofluazide, trade name Aprinox, is a thiazide diuretic used to treat hypertension.
Bendroflumethiazide is a thiazid ...
as Aldactide, Lasilacton, Lasilactone, and Spiromide, with altizide as Aldactacine and Aldactazine, with furosemide
Furosemide is a loop diuretic medication used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It may also be used for the treatment of high blood pressure. It can be taken by injection into a vein or by m ...
as Fruselac, with benazepril
Benazepril, sold under the brand name Lotensin among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It is a reasonable initial treatment for high blood pressure. It is taken by mouth. Ver ...
as Cardalis (veterinary), with metolazone
Metolazone is a thiazide-like diuretic marketed under the brand names Zytanix, Metoz, Zaroxolyn, and Mykrox. It is primarily used to treat congestive heart failure and high blood pressure. Metolazone indirectly decreases the amount of water rea ...
as Metolactone, with bendroflumethiazide
Bendroflumethiazide, formerly bendrofluazide, trade name Aprinox, is a thiazide diuretic used to treat hypertension.
Bendroflumethiazide is a thiazide diuretic which works by inhibiting sodium reabsorption at the beginning of the distal convolut ...
as Sali-Aldopur, and with torasemide
Torasemide, also known as torsemide, is a diuretic medication used to treat fluid overload due to heart failure, kidney disease, and liver disease and high blood pressure. It is a less preferred treatment for high blood pressure. It is taken by ...
as Dytor Plus, Torlactone, and Zator Plus.
Availability
Spironolactone is marketed widely throughout the world and is available in almost every country, including in the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, the United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
, other Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
an countries, Australia, New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
, South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
, Central and South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
, and East
East or Orient is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth.
Etymology
As in other languages, the word is formed from the fac ...
and Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainlan ...
.
Usage
There was a total of 17.2 million prescriptions for spironolactone in the United States between the beginning of 2003 and the end of 2005. There was a total of 12.0 million prescriptions for spironolactone in the United States in 2016 alone. It was the 66th top prescribed medication in the United States in 2016.
Research
Prostate conditions
Spironolactone has been studied at a high dosage in the treatment of benign prostatic hyperplasia
Benign prostatic hyperplasia (BPH), also called prostate enlargement, is a noncancerous increase in size of the prostate gland. Symptoms may include frequent urination, trouble starting to urinate, weak stream, inability to urinate, or loss o ...
(BPH; enlarged prostate). It was found to be better than placebo in terms of symptom relief following three months of treatment. However, this was not maintained after six months of treatment, by which point the improvements had largely disappeared. Moreover, no difference was observed between spironolactone and placebo with regard to volume of residual urine or prostate size. Gynecomastia was observed in about 5% of people. On the basis of these results, it has been said that spironolactone has no place in the treatment of BPH.
Spironolactone has been studied and used limitedly in the treatment of prostate cancer.
Epstein–Barr virus
Spironolactone has been found to block Epstein–Barr virus
The Epstein–Barr virus (EBV), formally called ''Human gammaherpesvirus 4'', is one of the nine known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. EBV is a double-stranded DNA virus.
It is b ...
(EBV) production and that of other human herpesviruses
''Herpesviridae'' is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word ''ἕρπει ...
by inhibiting the function of an EBV protein SM, which is essential for infectious virus production. This effect of spironolactone was determined to be independent of its antimineralocorticoid actions. Thus, spironolactone or compounds based on it have the potential to yield novel antiviral medication
Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do ...
s with a distinct mechanism of action and limited toxicity.
Other conditions
Spironolactone has been studied in the treatment of rosacea
Rosacea is a long-term skin condition that typically affects the face. It results in redness, pimples, swelling, and small and superficial dilated blood vessels. Often, the nose, cheeks, forehead, and chin are most involved. A red, enlarg ...
in both males and females.
Spironolactone has been studied in fibromyalgia in women. It has also been studied in bulimia nervosa
Bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging or fasting, and excessive concern with body shape and weight. The aim of this activity is to expel the body of calories eaten ...
in women, but was not found to be effective.
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