Medroxyprogesterone acetate (MPA), also known as depot medroxyprogesterone acetate (DMPA) in
injectable form and sold under the brand name Depo-Provera among others, is a
hormonal medication of the
progestin
A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural female sex hormone progesterone in the body. A progestin is a ''synthetic'' progestogen. Pro ...
type.
It is used as a method of birth control
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth contr ...
and as a part of menopausal hormone therapy. It is also used to treat endometriosis
Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fa ...
, abnormal uterine bleeding, abnormal sexuality in males, and certain types of cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
.[ The medication is available both alone and in combination with 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 ...
. It is taken by mouth, used under the tongue, or by injection into a muscle or fat.
Common side effects include menstrual disturbances such as absence of periods, abdominal pain
Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues.
Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a m ...
, and headache
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
Headaches can occur as a result ...
s.[ More serious side effects include bone loss, ]blood clot
A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cr ...
s, allergic reaction
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derm ...
s, and liver problems.[ Use is not recommended during ]pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ...
as it may harm the baby.[ MPA is an ]artificial
Artificiality (the state of being artificial or manmade) is the state of being the product of intentional human manufacture, rather than occurring naturally through processes not involving or requiring human activity.
Connotations
Artificiality ...
progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...
, and as such activates the progesterone receptor, the biological target of progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
. It also has androgenic activity and weak glucocorticoid activity. Due to its progestogenic activity, MPA decreases the body's release of gonadotropins and can suppress sex hormone
Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effect ...
levels. It works as a form of birth control by preventing ovulation.[
MPA was discovered in 1956 and was introduced for medical use 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 Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
in 1959.[ It is on the World Health Organization's List of Essential Medicines.] MPA is the most widely used progestin in menopausal hormone therapy and in progestogen-only birth control
Progestogen-only contraception (or progestin-only contraception) relies on progestogens alone to achieve contraception. It is one of the two major types of hormonal contraception, with the other major type being combined hormonal contraceptive me ...
. DMPA is approved for use as a form of long-acting birth control in more than 100 countries. In 2020, it was the 214th most commonly prescribed medication in the United States, with more than 2million prescriptions.
Medical uses
The most common use of MPA is in the form of DMPA as a long-acting progestogen-only injectable contraceptive to prevent pregnancy in women. It is an extremely effective contraceptive
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth contr ...
when used with relatively high doses to prevent ovulation. MPA is also used in combination with an estrogen in menopausal hormone therapy in postmenopausal women to treat and prevent menopausal symptoms such as hot flash
Hot flashes (also known as hot flushes) are a form of flushing, often caused by the changing hormone levels that are characteristic of menopause. They are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, an ...
es, vaginal atrophy, and osteoporosis
Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and consequent increase in fracture risk. It is the most common reason for a broken bone a ...
. It is used in menopausal hormone therapy specifically to prevent endometrial hyperplasia
Endometrial hyperplasia is a condition of excessive proliferation of the cells of the endometrium, or inner lining of the uterus.
Most cases of endometrial hyperplasia result from high levels of estrogens, combined with insufficient levels of t ...
and cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
that would otherwise be induced by prolonged unopposed estrogen therapy in women with intact uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...
es. In addition to contraception and menopausal hormone therapy, MPA is used in the treatment of gynecological
Gynaecology or gynecology (see spelling differences) is the area of medicine that involves the treatment of women's diseases, especially those of the reproductive organs. It is often paired with the field of obstetrics, forming the combined a ...
and menstrual disorders such as dysmenorrhea
Dysmenorrhea, also known as period pain, painful periods or menstrual cramps, is pain during menstruation. Its usual onset occurs around the time that menstruation begins. Symptoms typically last less than three days. The pain is usually in th ...
, amenorrhea, and endometriosis
Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fa ...
. Along with other progestins, MPA was developed to allow for oral progestogen therapy, as progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
(the progestogen hormone made by the human body) could not be taken orally for many decades before the process of micronization was developed and became feasible in terms of pharmaceutical manufacturing
Pharmaceutical manufacturing is the process of industrial-scale synthesis of pharmaceutical drugs as part of the pharmaceutical industry. The process of drug manufacturing can be broken down into a series of unit operations, such as milling, gra ...
.
DMPA reduces sex drive in men and is used as a form of chemical castration
Chemical castration is castration via anaphrodisiac drugs, whether to reduce libido and sexual activity, to treat cancer, or otherwise. Unlike surgical castration, where the gonads are removed through an incision in the body, to control inappropriate or unwanted sexual behavior in those with paraphilias or hypersexuality, including in convicted sex offenders. DMPA has also been used to treat benign prostatic hyperplasia, as a palliative
Palliative care (derived from the Latin root , or 'to cloak') is an interdisciplinary medical caregiving approach aimed at optimizing quality of life and mitigating suffering among people with serious, complex, and often terminal illnesses. Wit ...
appetite stimulant
An orexigenic, or appetite stimulant, is a drug, hormone, or compound that increases appetite and may induce hyperphagia. This can be a medication or a naturally occurring neuropeptide hormone, such as ghrelin, orexin or neuropeptide Y, which incre ...
for cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
patients, and at high doses (800 mg per day) to treat certain hormone-dependent cancers including endometrial cancer
Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most ...
, renal cancer, and 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 ...
. MPA has also been prescribed in 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 so ...
due to its progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...
ic and functional antiandrogenic effects. It has been used to delay puberty in children with precocious puberty but is not satisfactory for this purpose as it is not able to completely suppress puberty. DMPA at high doses has been reported to be definitively effective in the treatment of hirsutism as well.
Though not used as a treatment for epilepsy
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...
, MPA has been found to reduce the frequency of seizures
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with lo ...
and does not interact with antiepileptic
Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...
medications. MPA does not interfere with blood clotting
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechan ...
and appears to improve blood parameters for women with sickle cell anemia. Similarly, MPA does not appear to affect 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 i ...
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 ...
, and may improve primary biliary cirrhosis
Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune disease of the liver. It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build ...
and chronic active hepatitis. Women taking MPA may experience spotting shortly after starting the medication but is not usually serious enough to require medical intervention. With longer use amenorrhea (absence of menstruation
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of ...
) can occur as can irregular menstruation which is a major source of dissatisfaction, though both can result in improvements with iron deficiency and risk of pelvic inflammatory disease
Pelvic inflammatory disease, also known as pelvic inflammatory disorder (PID), is an infection of the upper part of the female reproductive system, namely the uterus, fallopian tubes, and ovaries, and inside of the pelvis. Often, there may be ...
and often do not result in discontinuation of the medication.[
]
Birth control
DMPA, under brand names such as Depo-Provera and Depo-SubQ Provera 104, is used in hormonal birth control as a long-lasting progestogen-only injectable contraceptive to prevent pregnancy in women. It is given by intramuscular
Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles ha ...
or subcutaneous injection
Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion.
A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, c ...
and forms a long-lasting depot, from which it is slowly released over a period of several months. It takes one week to take effect if given after the first five days of the period cycle, and is effective immediately if given during the first five days of the period cycle. Estimates of first-year failure rates are about 0.3%. MPA is effective in preventing pregnancy, but offers no protection against sexually transmitted infection
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are spread by sexual activity, especially vaginal intercourse, anal sex, and ora ...
s (STIs).
Effectiveness
Trussell's estimated ''perfect use'' first-year failure rate for DMPA as the average of failure rates in seven clinical trials at 0.3%. It was considered ''perfect use'' because the clinical trials measured efficacy during actual use of DMPA defined as being no longer than 14 or 15 weeks after an injection (i.e., no more than 1 or 2 weeks late for a next injection).
Prior to 2004, Trussell's ''typical use'' failure rate for DMPA was the same as his ''perfect use'' failure rate: 0.3%.
* DMPA estimated ''typical use'' first-year failure rate = 0.3% in:
** ''Contraceptive Technology, 16th revised edition'' (1994)
** ''Contraceptive Technology, 17th revised edition'' (1998)
*** Adopted in 1998 by the FDA for its current ''Uniform Contraceptive Labeling'' guidance
In 2004, using the 1995 NSFG failure rate, Trussell increased (by 10 times) his ''typical use'' failure rate for DMPA from 0.3% to 3%.
* DMPA estimated ''typical use'' first-year failure rate = 3% in:
** ''Contraceptive Technology, 18th revised edition'' (2004)
** ''Contraceptive Technology, 19th revised edition'' (2007)
Trussell did not use 1995 NSFG failure rates as ''typical use'' failure rates for the other two then newly available long-acting contraceptives, the Norplant implant (2.3%) and the ParaGard copper T 380A IUD
An intrauterine device (IUD), also known as intrauterine contraceptive device (IUCD or ICD) or coil, is a small, often T-shaped birth control device that is inserted into the uterus to prevent pregnancy. IUDs are one form of long-acting reversi ...
(3.7%), which were (as with DMPA) an order of magnitude higher than in clinical trials. Since Norplant and ParaGard allow no scope for user error, their much higher 1995 NSFG failure rates were attributed by Trussell to contraceptive overreporting at the time of a conception leading to a live birth.
Advantages
DMPA has a number of advantages and benefits:
* Highly effective at preventing pregnancy.
* Injected every 12 weeks. The only continuing action is to book subsequent follow-up injections every twelve weeks, and to monitor side effects to ensure that they do not require medical attention.
* No 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 ...
. No increased risk of deep vein thrombosis, pulmonary embolism, stroke
A stroke is a disease, medical condition in which poor cerebral circulation, blood flow to the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemorr ...
, or myocardial infarction
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 ...
.
* Minimal drug interactions (compared to other hormonal contraceptives).
* Decreased risk of endometrial cancer
Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most ...
. DMPA reduces the risk of endometrial cancer by 80%. The reduced risk of endometrial cancer in DMPA users is thought to be due to both the direct anti-proliferative effect of progestogen on the endometrium and the indirect reduction of estrogen levels by suppression of ovarian follicular development.
* Decreased risk of iron deficiency anemia
Iron-deficiency anemia is anemia caused by a lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as feeling tired, weak, sho ...
, pelvic inflammatory disease (PID), ectopic pregnancy
Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women have both of these symptom ...
, and uterine fibroids.
* Decreased symptoms of endometriosis
Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fa ...
.
* Decreased incidence of primary dysmenorrhea, ovulation pain, and functional ovarian cysts.
* Decreased incidence of seizures
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with lo ...
in women with epilepsy
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...
. Additionally, unlike most other hormonal contraceptives, DMPA's contraceptive effectiveness is not affected by enzyme-inducing antiepileptic drugs
Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...
.
* Decreased incidence and severity of sickle cell crises in women with sickle-cell disease.
The United Kingdom Department of Health has actively promoted Long Acting Reversible Contraceptive use since 2008, particularly for young people; following on from the October 2005 National Institute for Health and Clinical Excellence guidelines. Giving advice on these methods of contraception has been included in the 2009 Quality and Outcomes Framework "good practice" for primary care.
Comparison
Proponents of bioidentical hormone therapy
Bioidentical hormone replacement therapy (BHRT), also known as bioidentical hormone therapy (BHT) or natural hormone therapy, is the use of hormones that are identical on a molecular level with endogenous hormones in hormone replacement therapy. ...
believe that progesterone offers fewer side effects and improved quality of life compared to MPA. The evidence for this view has been questioned; MPA is better absorbed when taken by mouth, with a much longer elimination 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 b ...
leading to more stable blood levels though it may lead to greater breast tenderness and more sporadic vaginal bleeding.[ The two compounds do not differentiate in their ability to suppress ]endometrial hyperplasia
Endometrial hyperplasia is a condition of excessive proliferation of the cells of the endometrium, or inner lining of the uterus.
Most cases of endometrial hyperplasia result from high levels of estrogens, combined with insufficient levels of t ...
,[ nor does either increase the risk of pulmonary embolism. The two medications have not been adequately compared in direct tests to clear conclusions about safety and superiority.]
Available forms
MPA is available alone in the form of 2.5, 5, and 10 mg 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 ...
tablet
Tablet may refer to:
Medicine
* Tablet (pharmacy), a mixture of pharmacological substances pressed into a small cake or bar, colloquially called a "pill"
Computing
* Tablet computer, a mobile computer that is primarily operated by touching the ...
s, as a 150 mg/mL (1 mL) or 400 mg/mL (2.5 mL) microcrystalline
A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination. There is little agreement on the range of crystal sizes that should be regarded as microcrystalline, but the ...
aqueous suspension for intramuscular injection
Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...
, and as a 104 mg (0.65 mL of 160 mg/mL) microcrystalline aqueous suspension for subcutaneous injection
Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion.
A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, c ...
. It has also been marketed in the form of 100, 200, 250, 400, and 500 mg oral tablets; 500 and 1,000 mg oral suspensions; and as a 50 mg/mL microcrystalline aqueous suspension for intramuscular injection. A 100 mg/mL microcrystalline aqueous suspension for intramuscular injection was previously available as well. In addition to single-drug formulations, MPA is available in the form of oral tablets in combination with conjugated estrogens (CEEs), estradiol, and estradiol valerate for use in menopausal hormone therapy, and is available in combination with estradiol cypionate in a microcrystalline aqueous suspension as a combined injectable contraceptive
Combined injectable contraceptives (CICs) are a form of hormonal birth control for women. They consist of monthly injections of combined formulations containing an estrogen and a progestin to prevent pregnancy.
CICs are different from progestoge ...
.
Depo-Provera is the brand name for a 150 mg microcrystalline aqueous suspension of DMPA that is administered by intramuscular injection. The shot must be injected into thigh, buttock, or deltoid muscle four times a year (every 11 to 13 weeks), and provides pregnancy protection instantaneously after the first injection.[Stacey, Dawn]
''Depo Provera: The Birth Control Shot''
Accessed 13 October 2009. Depo-subQ Provera 104 is a variation of the original intramuscular DMPA that is instead a 104 mg microcrystalline dose in aqueous suspension administered by subcutaneous injection. It contains 69% of the MPA found in the original intramuscular DMPA formulation. It can be injected using a smaller injection needle inserting the medication just below the skin, instead of into the muscle, in either the abdomen or thigh. This subcutaneous injection claims to reduce the side effects of DMPA while still maintaining all the same benefits of the original intramuscular DMPA.
Contraindications
MPA is not usually recommended because of unacceptable health risk or because it is not indicated in the following cases:
Conditions where the theoretical or proven risks usually outweigh the advantages of using DMPA:
* Multiple risk factors for arterial cardiovascular disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, hea ...
* Current deep vein thrombosis or pulmonary embolus
* Migraine headache
Migraine (, ) is a common neurological disorder characterized by recurrent headaches. Typically, the associated headache affects one side of the head, is pulsating in nature, may be moderate to severe in intensity, and could last from a few h ...
with aura
Aura most commonly refers to:
* Aura (paranormal), a field of luminous multicolored radiation around a person or object
* Aura (symptom), a symptom experienced before a migraine or seizure
Aura may also refer to:
Places Extraterrestrial
* 1488 ...
while using DMPA
* Before evaluation of unexplained vaginal bleeding suspected of being a serious condition
* A history 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 ...
and no evidence of current disease for five years
* Active liver disease: (acute viral hepatitis, severe decompensated 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 ...
, benign or malignant liver tumours)
* Conditions of concern for estrogen deficiency and reduced HDL levels theoretically increasing cardiovascular risk:
** Hypertension
Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...
with vascular disease
Vascular disease is a class of diseases of the blood vessels – the arteries and veins of the circulatory system of the body. Vascular disease is a subgroup of cardiovascular disease. Disorders in this vast network of blood vessels can cause a ...
** Current and history of ischemic heart disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pl ...
** History of stroke
A stroke is a disease, medical condition in which poor cerebral circulation, blood flow to the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemorr ...
** Diabetes
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 ...
for over 20 years or with nephropathy/ retinopathy/neuropathy
Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or o ...
or vascular disease
Vascular disease is a class of diseases of the blood vessels – the arteries and veins of the circulatory system of the body. Vascular disease is a subgroup of cardiovascular disease. Disorders in this vast network of blood vessels can cause a ...
Conditions which represent an unacceptable health risk if DMPA is used:
* Current or recent 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 hormonally sensitive tumour)
Conditions where use is not indicated and should not be initiated:
* Pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ...
MPA is not recommended for use prior to menarche
Menarche ( ; ) is the first menstrual cycle, or first menstrual bleeding, in female humans. From both social and medical perspectives, it is often considered the central event of female puberty, as it signals the possibility of fertility.
Gir ...
or before or during recovery from surgery
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pa ...
.
Side effects
In women, the most common adverse effect
An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a " side effect", when judged to be secondary to a main or therapeutic effect. The term compl ...
s of MPA are acne, changes in menstrual flow, drowsiness, and can cause 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 if taken by pregnant women. Other common side effects include breast tenderness, increased facial hair, decreased scalp hair, difficulty falling or remaining asleep, stomach pain, and weight loss or gain.[ Lowered libido has been reported as a side effect of MPA in women.] DMPA can affect menstrual bleeding. After a year of use, 55% of women experience amenorrhea (missed periods); after two years, the rate rises to 68%. In the first months of use "irregular or unpredictable bleeding or spotting, or, rarely, heavy or continuous bleeding" was reported. MPA does not appear to be associated with vitamin B12 deficiency. Data on weight gain with DMPA likewise are inconsistent.
At high doses for the treatment of breast cancer, MPA can cause weight gain and can worsen 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 ...
and edema
Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels tight, the area ma ...
(particularly of the face). Adverse effects peak at five weeks, and are reduced with lower doses. Less frequent effects may include thrombosis
Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (th ...
(though it is not clear if this is truly a risk, it cannot be ruled out), painful urination, headache
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
Headaches can occur as a result ...
, 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 th ...
, and 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, gastroenter ...
. When used as a form of androgen deprivation therapy
Androgen deprivation therapy (ADT), also called androgen suppression therapy, is an antihormone therapy whose main use is in treating prostate cancer. Prostate cancer cells usually require androgen hormones, such as testosterone, to grow. ADT red ...
in men, more frequent complaints include reduced libido, impotence, reduced ejaculate volume, and within three days, chemical castration
Chemical castration is castration via anaphrodisiac drugs, whether to reduce libido and sexual activity, to treat cancer, or otherwise. Unlike surgical castration, where the gonads are removed through an incision in the body, . At extremely high doses (used to treat cancer, not for contraception) MPA may cause adrenal suppression and may interfere with carbohydrate metabolism, but does not cause diabetes
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 ...
.
When used as a form of injected birth control, there is a delayed return of fertility
Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Ferti ...
. The average return to fertility is 9 to 10 months after the last injection, taking longer for overweight or obese women. By 18 months after the last injection, fertility is the same as that in former users of other contraceptive methods. 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 exposed to progestogens have demonstrated higher rates of genital abnormalities, low birth weight, and increased ectopic pregnancy
Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women have both of these symptom ...
particularly when MPA is used as an injected form of long-term birth control. A study of accidental pregnancies among poor women in Thailand found that infants who had been exposed to DMPA during pregnancy had a higher risk of low birth weight and an 80% greater-than-usual chance of dying in the first year of life.
Mood changes
There have been concerns about a possible risk of depression and mood changes with progestins like MPA, and this has led to reluctance of some clinicians and women to use them. However, contrary to widely-held beliefs, most research suggests that progestins do not cause adverse psychological effects such as depression or anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...
. A 2018 systematic review of the relationship between progestin-based contraception and depression included three large studies of DMPA and reported no association between DMPA and depression. According to a 2003 review of DMPA, the majority of published clinical studies indicate that DMPA is not associated with depression, and the overall data support the notion that the medication does not significantly affect mood.
In the largest study to have assessed the relationship between MPA and depression to date, in which over 3,900 women were treated with DMPA for up to 7 years, the incidence of depression was infrequent at 1.5% and the discontinuation rate due to depression was 0.5%. This study did not include baseline data on depression, and due to the incidence of depression in the study, the FDA required package labeling for DMPA stating that women with depression should be observed carefully and that DMPA should be discontinued if depression recurs. A subsequent study of 495 women treated with DMPA over the course of 1 year found that the mean depression score slightly decreased in the whole group of continuing users from 7.4 to 6.7 (by 9.5%) and decreased in the quintile of that group with the highest depression scores at baseline from 15.4 to 9.5 (by 38%). Based on the results of this study and others, a consensus began emerging that DMPA does not in fact increase the risk of depression nor worsen the severity of pre-existing depression.
Similarly to the case of DMPA for hormonal contraception, the Heart and Estrogen/Progestin Replacement Study (HERS), a study of 2,763 postmenopausal women treated with 0.625 mg/day oral CEEs plus 2.5 mg/day oral MPA or placebo for 36 months as a method of menopausal hormone therapy, found no change in depressive symptoms. However, some small studies have reported that progestins like MPA might counteract beneficial effects of estrogens against depression.
Long-term effects
The Women's Health Initiative investigated the use of a combination of oral CEEs and MPA compared to placebo. The study was prematurely terminated when previously unexpected risks were discovered, specifically the finding that though the all-cause mortality was not affected by the hormone therapy, the benefits of menopausal hormone therapy (reduced risk of hip fracture, colorectal
The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being rem ...
and endometrial cancer
Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most ...
and all other causes of death) were offset by increased risk of coronary heart disease, 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 ...
, stroke
A stroke is a disease, medical condition in which poor cerebral circulation, blood flow to the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemorr ...
s and pulmonary embolism.
When combined with CEEs, MPA has been associated with an increased risk of breast cancer, dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
, and thrombus
A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of ...
in the eye. In combination with estrogens in general, MPA may increase the risk of cardiovascular disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, hea ...
, with a stronger association when used by postmenopausal women also taking CEEs. It was because of these unexpected interactions that the Women's Health Initiative study was ended early due to the extra risks of menopausal hormone therapy, resulting in a dramatic decrease in both new and renewal prescriptions for hormone therapy.
Long-term studies of users of DMPA have found slight or no increased overall risk of breast cancer. However, the study population did show a slightly increased risk of breast cancer in recent users (DMPA use in the last four years) under age 35, similar to that seen with the use of combined oral contraceptive 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: proges ...
s.
Blood clots
DMPA has been associated in multiple studies with a higher risk of venous thromboembolism
Venous thrombosis is blockage of a vein caused by a thrombus (blood clot). A common form of venous thrombosis is deep vein thrombosis (DVT), when a blood clot forms in the deep veins. If a thrombus breaks off (embolizes) and flows to the lungs to ...
(VTE) when used as a form of progestogen-only birth control in premenopausal women. The increase in incidence of VTE ranges from 2.2-fold to 3.6-fold. Elevated risk of VTE with DMPA is unexpected, as DMPA has little or no effect on coagulation
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism ...
and fibrinolytic factor
Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. Primary fibrinolysis is a normal body process, while secondary fibrinolysis is the breakdown of clots due to a medicine, a medical disorder, or some other c ...
s, and progestogens by themselves normally do not increase the risk of thrombosis. It has been argued that the higher incidence with DMPA has reflected preferential prescription of DMPA to women considered to be at an increased risk of VTE. Alternatively, it is possible that MPA may be an exception among progestins in terms of VTE risk. A 2018 meta-analysis
A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting m ...
reported that MPA was associated with a 2.8-fold higher risk of VTE than other progestins. It is possible that the glucocorticoid activity of MPA may increase the risk of VTE.
Bone density
DMPA may cause reduced bone density in premenopausal women and in men when used without an estrogen, particularly at high doses, though this appears to be reversible to a normal level even after years of use.
On 17 November 2004, the United States Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
put a black box warning
In the United States, a boxed warning (sometimes "black box warning", colloquially) is a type of warning that appears on the package insert for certain prescription drugs, so called because
the U.S. Food and Drug Administration specifies that i ...
on the label, indicating that there were potential adverse effects of loss of bone mineral density. While it causes temporary bone loss, most women fully regain their bone density after discontinuing use. The World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...
(WHO) recommends that the use not be restricted. The American College of Obstetricians and Gynecologists notes that the potential adverse effects on BMD be balanced against the known negative effects of unintended pregnancy using other birth control methods or no method, particularly among adolescents.
Three studies have suggested that bone loss is reversible after the discontinuation of DMPA. Other studies have suggested that the effect of DMPA use on postmenopausal bone density is minimal, perhaps because DMPA users experience less bone loss at menopause. Use after peak bone mass is associated with increased bone turnover but no decrease in bone mineral density.
The FDA recommends that DMPA not be used for longer than two years, unless there is no viable alternative method of contraception, due to concerns over bone loss. However, a 2008 Committee Opinion from the American Congress of Obstetricians and Gynecologists
The American College of Obstetricians and Gynecologists (ACOG) is a professional association of physicians specializing in obstetrics and gynecology in the United States. Several Latin American countries are also represented within Districts o ...
(ACOG) advises healthcare providers that concerns about bone mineral density loss should neither prevent the prescription of or continuation of DMPA beyond two years of use.
HIV risk
There is uncertainty regarding the risk of HIV acquisition among DMPA users; some observational studies suggest an increased risk of HIV acquisition among women using DMPA, while others do not. The World Health Organization issued statements in February 2012 and July 2014 saying the data did not warrant changing their recommendation of no restriction – Medical Eligibility for Contraception (MEC) category 1 – on the use of DMPA in women at high risk for HIV. Two meta-analyses of observational studies in sub-Saharan Africa were published in January 2015. They found a 1.4- to 1.5-fold increase risk of HIV acquisition for DMPA users relative to no hormonal contraceptive use. In January 2015, the Faculty of Sexual & Reproductive Healthcare of the Royal College of Obstetricians and Gynaecologists issued a statement reaffirming that there is no reason to advise against use of DMPA in the United Kingdom even for women at 'high risk' of HIV infection. A systematic review and meta-analysis of risk of HIV infection in DMPA users published in fall of 2015 stated that "the epidemiological and biological evidence now make a compelling case that DMPA adds significantly to the risk of male-to-female HIV transmission." In 2019, a randomized controlled trial found no significant association between DMPA use and HIV.
Breastfeeding
MPA may be used by breastfeeding
Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that bre ...
mothers. Heavy bleeding is possible if given in the immediate postpartum time and is best delayed until six weeks after birth. It may be used within five days if not breast feeding. While a study showed "no significant difference in birth weights or incidence of birth defects" and "no significant alternation of immunity to infectious disease caused by breast milk containing DMPA", a subgroup of babies whose mothers started DMPA at two days postpartum had a 75% higher incidence of doctor visits for infectious diseases during their first year of life.
A larger study with longer follow-up concluded that "use of DMPA during pregnancy or breastfeeding does not adversely affect the long-term growth and development of children". This study also noted that "children with DMPA exposure during pregnancy and lactation had an increased risk of suboptimal growth in height," but that "after adjustment for socioeconomic factors by multiple logistic regression, there was no increased risk of impaired growth among the DMPA-exposed children." The study also noted that effects of DMPA exposure on puberty require further study, as so few children over the age of 10 were observed.
Overdose
MPA has been studied at "massive" dosages of up to 5,000 mg per day orally and 2,000 mg per day via intramuscular injection, without major tolerability or 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 di ...
issues described. Overdose is not described in the Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
(FDA) product labels for injected MPA (Depo-Provera or Depo-SubQ Provera 104). In the FDA product label for oral MPA (Provera), it is stated that overdose of an estrogen and progestin may cause 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 th ...
and 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, gastroenter ...
, breast tenderness, 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 ...
, abdominal pain
Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues.
Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a m ...
, drowsiness, fatigue
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
, and withdrawal bleeding
Vaginal bleeding is any expulsion of blood from the vagina. This bleeding may originate from the uterus, vaginal wall, or cervix. Generally, it is either part of a normal menstrual cycle or is caused by hormonal or other problems of the reproductiv ...
. According to the label, treatment of overdose should consist of discontinuation of MPA therapy and symptomatic care.
Interactions
MPA increases the risk 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 ...
, dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
, and thrombus
A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of ...
when used in combination with CEEs to treat menopausal symptoms.[ When used as a contraceptive, MPA does not generally ]interact
Advocates for Informed Choice, doing business as, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex trai ...
with other medications. The combination of MPA with aminoglutethimide
Aminoglutethimide (AG), sold under the brand names Elipten, Cytadren, and Orimeten among others, is a medication which has been used in the treatment of seizures, Cushing's syndrome, breast cancer, and prostate cancer, among other indications. ...
to treat metastases
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, the ...
from breast cancer has been associated with an increase in depression.[ St John's wort may decrease the effectiveness of MPA as a contraceptive due to acceleration of its ]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 ...
.[
]
Pharmacology
Pharmacodynamics
MPA acts as an agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ag ...
of the progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
, androgen, and glucocorticoid receptors (PR, AR, and GR, respectively), activating these receptors with EC50 values of approximately 0.01 nM, 1 nM, and 10 nM, respectively. It has negligible affinity for the estrogen receptor. The medication has relatively high affinity for the mineralocorticoid receptor, but in spite of this, it has no 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 ...
or antimineralocorticoid activity. The intrinsic activities of MPA in activating the PR and the AR have been reported to be at least equivalent to those of progesterone 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 includi ...
(DHT), respectively, indicating that it is a full agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the a ...
of these receptors.
Progestogenic activity
MPA is a potent agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ag ...
of the progesterone receptor with similar affinity and efficacy
Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as ''effectiveness'', and it has often been used synonymously, although in pharmacology a distinction is now often made between ...
relative to progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
. While both MPA and its deacetylated analogue medroxyprogesterone
Medroxyprogesterone (MP), is a progestin which is not used medically. A derivative, medroxyprogesterone acetate (MPA), is used as a medication in humans, and is far more widely known in comparison. ''Medroxyprogesterone'' is sometimes used as a ...
bind to and agonize the PR, MPA has approximately 100-fold higher binding affinity
In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a mo ...
and transactivation potency in comparison. As such, unlike MPA, medroxyprogesterone is not used clinically, though it has seen some use in veterinary medicine
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 ...
. The oral dosage of MPA required to inhibit ovulation (i.e., the effective contraceptive dosage) is 10 mg/day, whereas 5 mg/day was not sufficient to inhibit ovulation in all women. In accordance, the dosage of MPA used in oral contraceptives in the past was 10 mg per tablet. For comparison to MPA, the dosage of progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
required to inhibit ovulation is 300 mg/day, whereas that of the 19-nortestosterone
Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate (brand name Durabolin). Nandrolon ...
derivatives norethisterone
Norethisterone, also known as norethindrone and sold under many brand names, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medication is available in b ...
and norethisterone acetate is only 0.4 to 0.5 mg/day.
The mechanism of action of progestogen-only contraceptives like DMPA depends on the progestogen activity and dose. High-dose progestogen-only contraceptives, such as DMPA, inhibit follicular development and prevent ovulation as their primary mechanism of action. The progestogen decreases the pulse frequency of gonadotropin-releasing hormone
Gonadotropin-releasing hormone (GnRH) is a releasing hormone responsible for the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. GnRH is a tropic peptide hormone synthesized and released ...
(GnRH) release by the hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus ...
, which decreases the release of follicle-stimulating hormone
Follicle-stimulating hormone (FSH) is a gonadotropin, a glycoprotein polypeptide hormone. FSH is synthesized and secreted by the gonadotropic cells of the anterior pituitary gland and regulates the development, growth, pubertal maturation, ...
(FSH) and luteinizing hormone (LH) by the anterior pituitary
A major organ of the endocrine system, the anterior pituitary (also called the adenohypophysis or pars anterior) is the glandular, anterior lobe that together with the posterior lobe (posterior pituitary, or the neurohypophysis) makes up the pi ...
. Decreased levels of FSH inhibit follicular development, preventing an increase in estradiol levels. Progestogen negative feedback
Negative feedback (or balancing feedback) occurs when some function of the output of a system, process, or mechanism is fed back in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by othe ...
and the lack 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 ...
positive feedback on LH release prevent a LH surge. Inhibition of follicular development and the absence of a LH surge prevent ovulation. A secondary mechanism of action of all progestogen-containing contraceptives is inhibition of sperm
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, ...
penetration by changes in the cervical mucus
The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long (~1 inch) and roughly cylindrical in shape, which changes during ...
. Inhibition of ovarian function during DMPA use causes the endometrium
The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The functional layer ...
to become thin and atrophic. These changes in the endometrium could, theoretically, prevent implantation. However, because DMPA is highly effective in inhibiting ovulation and sperm penetration, the possibility of fertilization
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Pro ...
is negligible. No available data support prevention of implantation as a mechanism of action of DMPA.
Antigonadotropic and anticorticotropic effects
MPA suppresses the hypothalamic–pituitary–adrenal (HPA) and hypothalamic–pituitary–gonadal (HPG) axes at sufficient dosages, resulting decreased levels of gonadotropins, androgens, 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, adrenocorticotropic hormone (ACTH), and cortisol
Cortisol is a steroid hormone, in the glucocorticoid class of hormones. When used as a medication, it is known as hydrocortisone.
It is produced in many animals, mainly by the '' zona fasciculata'' of the adrenal cortex in the adrenal g ...
, as well as levels of sex hormone-binding globulin (SHBG). There is evidence that the suppressive effects of MPA on the HPG axis are mediated by activation of both the PR and the AR in the pituitary gland
In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The h ...
. Due to its effects on androgen levels, MPA can produce strong functional antiandrogenic effects, and is used in the treatment of androgen-dependent conditions such as precocious puberty in boys and hypersexuality in men. In addition, since the medication suppresses estrogen levels as well, MPA can produce strong functional antiestrogenic effects similarly, and has been used to treat estrogen-dependent condition An estrogen-dependent condition can be that relating to the differentiation in the steroid sex hormone that is associated with the female reproductive system and sex characteristics. These conditions can fall under the umbrella of hypoestrogenism, h ...
s such as precocious puberty in girls and endometriosis
Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fa ...
in women. Due to low estrogen levels, the use of MPA without an estrogen poses a risk of decreased bone mineral 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 optical ...
and other symptoms of estrogen deficiency.
Oral MPA has been found to suppress testosterone levels in men by about 30% (from 831 ng/dL to 585 ng/dL) at a dosage of 20 mg/day, by about 45 to 75% (average 60%; to 150–400 ng/dL) at a dosage of 60 mg/day, and by about 70 to 75% (from 832–862 ng/dL to 214–251 ng/dL) at a dosage of 100 mg/day. Dosages of oral MPA of 2.5 to 30 mg/day in combination with estrogens have been used to help suppress testosterone levels in transgender women. One study of injectable MPA in men with benign prostatic hyperplasia reported that a single 150 mg dose suppressed testosterone levels into the defined male castrate range (<58 ng/dL) within 7 days and that castration levels of testosterone were maintained for 3 months. Very high doses of intramuscular MPA of 150 to 500 mg per week (but up to 900 mg per week) have similarly been reported to suppress testosterone levels to less than 100 ng/dL. The typical initial dose of intramuscular MPA for testosterone suppression in men with paraphilias is 400 or 500 mg per week.
Androgenic activity
MPA is a potent full agonist of the AR. Its activation of the AR may play an important and major role in its antigonadotropic effects and in its beneficial effects against 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 ...
. However, although MPA may produce androgenic side effects such as 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 in some women,. In fact, likely due to its suppressive actions on androgen levels, it has been reported that MPA is generally highly effective in improving pre-existing symptoms of hirsutism in women with the condition. However, MPA has been seen to cause androgenic effects in children with precocious puberty. The reason for the general lack of virilizing effects with MPA, despite it binding to and activating the AR with high affinity and this action potentially playing an important role in many of its physiological and therapeutic effects, is not entirely clear. However, MPA has been found to interact with the AR differently compared to other agonists of the receptor such as 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 includi ...
(DHT). The result of this difference appears to be that MPA binds to the AR with a similar affinity and intrinsic activity to that of DHT, but requires about 100-fold higher concentrations for a comparable induction of gene transcription, while at the same time not antagonizing the transcriptional activity of normal androgens like DHT at any concentration. Thus, this may explain the low propensity of MPA for producing androgenic side effects.
MPA shows weak androgenic effects on liver protein synthesis, similarly to other weakly androgenic progestins like megestrol acetate and 19-nortestosterone
Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate (brand name Durabolin). Nandrolon ...
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. While it does not antagonize estrogen-induced increases in levels of triglyceride
A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and ''glyceride'').
Triglycerides are the main constituents of body fat in humans and other vertebrates, as ...
s and HDL cholesterol, DMPA every other week may decrease levels of HDL cholesterol. In addition, MPA has been found to suppress sex hormone-binding globulin (SHBG) production by 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 i ...
. At a dosage of 10 mg/day oral MPA, it has been found to decrease circulating SHBG levels by 14 to 18% in women taking 4 mg/day oral estradiol valerate. Conversely, in a study that combined 2.5 mg/day oral MPA with various oral estrogens, no influence of MPA on estrogen-induced increases in SHBG levels was discerned. In another, higher-dose study, SHBG levels were lower by 59% in a group of women treated with 50 mg/day oral MPA alone relative to an untreated control group of women. In massive-dose studies of oral or injectable MPA (e.g., 500–1,000 mg/day), the medication decreased SHBG levels by about 80%.
Unlike the related steroids megestrol acetate and cyproterone acetate, MPA is not an antagonist
An antagonist is a character in a story who is presented as the chief foe of the protagonist.
Etymology
The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, ri ...
of the AR and does not have direct antiandrogenic activity. As such, although MPA is sometimes described as an antiandrogen, it is not a "true" antiandrogen (i.e., AR antagonist).
Glucocorticoid activity
As an agonist of the GR, MPA has glucocorticoid activity, and as a result can cause symptoms of Cushing's syndrome, steroid diabetes
Steroid diabetes is a medical term referring to prolonged hyperglycemia due to glucocorticoid therapy for another medical condition. It is usually, but not always, a transient condition.
Cause
The most common glucocorticoids which cause steroi ...
, and adrenal insufficiency
Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones. The adrenal gland normally secretes glucocorticoids (primarily cortisol), mineralocorticoids (primarily aldosterone), and andro ...
at sufficiently high doses. It has been suggested that the glucocorticoid activity of MPA may contribute to bone loss. The glucocorticoid activity of MPA may also result in an upregulation of the thrombin receptor
There are three known thrombin receptors (ThrR), termed PAR1, PAR3 and PAR4 (PAR for protease-activated receptor).
G-protein-coupled receptors that are responsible for the coagulation effects and responses of thrombin on cells are known as prote ...
in blood vessel
The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide awa ...
walls, which may contribute to procoagulant effects of MPA and risk of venous thromboembolism
Venous thrombosis is blockage of a vein caused by a thrombus (blood clot). A common form of venous thrombosis is deep vein thrombosis (DVT), when a blood clot forms in the deep veins. If a thrombus breaks off (embolizes) and flows to the lungs to ...
and atherosclerosis. The relative glucocorticoid activity of MPA is among the highest of the clinically used progestins.
Steroidogenesis inhibition
MPA has been found to act as a competitive inhibitor
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 neurotra ...
of rat 3α-hydroxysteroid dehydrogenase (3α-HSD). This 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 ...
is essential for the transformation of progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
, deoxycorticosterone, and DHT into inhibitory neurosteroid
Neurosteroids, also known as neuroactive steroids, are endogenous or exogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. The term ''neurosteroid'' was co ...
s such as allopregnanolone
Allopregnanolone is a naturally occurring neurosteroid which is made in the body from the hormone progesterone. As a medication, allopregnanolone is referred to as brexanolone, sold under the brand name Zulresso, and used to treat postpartum ...
, , and 3α-androstanediol, respectively. MPA has been described as very potent in its inhibition of rat 3α-HSD, with an IC50 of 0.2 μM and a Ki (in rat testicular homogenate
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, ...
s) of 0.42 μM. However, inhibition of 3α-HSD by MPA does not appear to have been confirmed using human proteins yet, and the concentrations required with rat proteins are far above typical human therapeutic concentrations.
MPA has been identified as a competitive inhibitor of human 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase II (3β-HSD II). This enzyme is essential for the biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecul ...
of sex steroid
Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effect ...
s and corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are inv ...
s. The Ki of MPA for inhibition of 3β-HSD II is 3.0 μM, and this concentration is reportedly near the circulating levels of the medication that are achieved by very high therapeutic dosages of MPA of 5 to 20 mg/kg/day (dosages of 300 to 1,200 mg/day for a 60 kg (132 lb) person). Aside from 3β-HSD II, other human steroidogenic enzymes, including cholesterol side-chain cleavage enzyme (P450scc/CYP11A1) and 17α-hydroxylase/17,20-lyase (CYP17A1), were not found to be inhibited by MPA. MPA has been found to be effective in the treatment of gonadotropin-independent precocious puberty and in 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 ...
in postmenopausal women at high dosages, and inhibition of 3β-HSD II could be responsible for its effectiveness in these conditions.
GABAA receptor allosteric modulation
Progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
, via transformation into neurosteroid
Neurosteroids, also known as neuroactive steroids, are endogenous or exogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. The term ''neurosteroid'' was co ...
s such as 5α-dihydroprogesterone
5α-Dihydroprogesterone (5α-DHP, allopregnanedione, or 5α-pregnane-3,20-dione) is an endogenous progestogen and neurosteroid that is synthesized from progesterone. It is also an intermediate in the synthesis of allopregnanolone and isopregnano ...
, 5β-dihydroprogesterone, allopregnanolone
Allopregnanolone is a naturally occurring neurosteroid which is made in the body from the hormone progesterone. As a medication, allopregnanolone is referred to as brexanolone, sold under the brand name Zulresso, and used to treat postpartum ...
, and pregnanolone
Pregnanolone, also known as eltanolone, is an endogenous inhibitory neurosteroid which is produced in the body from progesterone. It is closely related to allopregnanolone, which has similar properties.
Biological activity
Pregnanolone is a ...
(catalyzed by the enzymes 5α- and 5β-reductase and 3α- and 3β-HSD), is a positive allosteric modulator of the GABAA receptor, and is associated with a variety of effects mediated by this property including 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 ...
, sedation
Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure. Examples of drugs which can be used for sedation include isoflurane, diethyl ether, ...
, hypnotic
Hypnotic (from Greek ''Hypnos'', sleep), or soporific drugs, commonly known as sleeping pills, are a class of (and umbrella term for) psychoactive drugs whose primary function is to induce sleep (or surgical anesthesiaWhen used in anesthesia ...
states, mood changes, anxiolysis, and cognitive/memory impairment, as well as effectiveness as an anticonvulsant
Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of ...
in the treatment of catamenial epilepsy. It has also been found to produce anesthesia
Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), ...
via this action in animals when administered at sufficiently high dosages. MPA was found to significantly reduce seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with lo ...
incidence when added to existing anticonvulsant regimens in 11 of 14 women with uncontrolled epilepsy
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...
, and has also been reported to induce anesthesia in animals, raising the possibility that it might modulate the GABAA receptor similarly to progesterone.
MPA shares some of the same metabolic routes of progesterone and, analogously, can be transformed into metabolites such as 5α-dihydro-MPA (DHMPA) and 3α,5α-tetrahydro-MPA (THMPA). However, unlike the reduced metabolites of progesterone, DHMPA and THMPA have been found not to modulate the GABAA receptor. Conversely, unlike progesterone, MPA itself actually modulates the GABAA receptor, although notably not at the neurosteroid binding site. However, rather than act as a potentiator of the receptor, MPA appears to act as a negative allosteric modulator. Whereas the reduced metabolites of progesterone enhance binding of the benzodiazepine
Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, ...
flunitrazepam
Flunitrazepam, also known as Rohypnol among other names, is a benzodiazepine used to treat severe insomnia and assist with anesthesia. As with other hypnotics, flunitrazepam has been advised to be prescribed only for short-term use or by those ...
to the GABAA receptor ''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 a ...
'', MPA can partially inhibit the binding of flunitrazepam by up to 40% with half-maximal inhibition at 1 μM. However, the concentrations of MPA required for inhibition are high relative to therapeutic concentrations, and hence, this action is probably of little or no clinical relevance. The lack of potentiation of the GABAA receptor by MPA or its metabolites is surprising in consideration of the apparent anticonvulsant and anesthetic effects of MPA described above, and they remain unexplained.
Clinical studies using massive dosages of up to 5,000 mg/day oral MPA and 2,000 mg/day intramuscular MPA for 30 days in women with advanced breast cancer have reported "no relevant side effects", which suggests that MPA has no meaningful direct action on the GABAA receptor in humans even at extremely high dosages.
Appetite stimulation
Although MPA and the closely related medication megestrol acetate are effective appetite stimulant
An orexigenic, or appetite stimulant, is a drug, hormone, or compound that increases appetite and may induce hyperphagia. This can be a medication or a naturally occurring neuropeptide hormone, such as ghrelin, orexin or neuropeptide Y, which incre ...
s at very high dosages, the mechanism of action of their beneficial effects on appetite
Appetite is the desire to eat food items, usually due to hunger. Appealing foods can stimulate appetite even when hunger is absent, although appetite can be greatly reduced by satiety. Appetite exists in all higher life-forms, and serves to regu ...
is not entirely clear. However, glucocorticoid, cytokine
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in au ...
, and possibly anabolic
Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breakin ...
-related mechanisms are all thought to possibly be involved, and a number of downstream changes have been implicated, including stimulation of the release of neuropeptide Y
Neuropeptide Y (NPY) is a 36 amino-acid neuropeptide that is involved in various physiological and homeostatic processes in both the central and peripheral nervous systems. NPY has been identified as the most abundant peptide present in the ma ...
in the hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus ...
, modulation of calcium channel
A calcium channel is an ion channel which shows selective permeability to calcium ions. It is sometimes synonymous with voltage-gated calcium channel, although there are also ligand-gated calcium channels.
Comparison tables
The following tables e ...
s in the ventromedial hypothalamus
The ventromedial nucleus of the hypothalamus (VMN, also sometimes referred to as the ventromedial hypothalamus, VMH) is a nucleus of the hypothalamus. "The ventromedial hypothalamus (VMH) is a distinct morphological nucleus involved in terminatin ...
, and inhibition of the secretion of proinflammatory cytokine An inflammatory cytokine or proinflammatory cytokine is a type of signaling molecule (a cytokine) that is secreted from immune cells like helper T cells (Th) and macrophages, and certain other cell types that promote inflammation. They include inte ...
s including IL-1α
Interleukin-1 alpha (IL-1 alpha) also known as hematopoietin 1 is a cytokine of the interleukin 1 family that in humans is encoded by the ''IL1A'' gene. In general, Interleukin 1 is responsible for the production of inflammation, as well as the ...
, IL-1β
Interleukin-1 beta (IL-1β) also known as leukocytic pyrogen, leukocytic endogenous mediator, mononuclear cell factor, lymphocyte activating factor and other names, is a cytokine protein that in humans is encoded by the ''IL1B'' gene."Catabolin ...
, IL-6, and TNF-α, actions that have all been linked to an increase in appetite.
Other activity
MPA weakly stimulates the proliferation of MCF-7 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 ...
cells ''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 a ...
'', an action that is independent of the classical PRs and is instead mediated via the progesterone receptor membrane component-1 (PGRMC1). Certain other progestins are also active in this assay, whereas progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
acts neutrally. It is unclear if these findings may explain the different risks of breast cancer observed with progesterone, dydrogesterone, and other progestins such as medroxyprogesterone acetate and norethisterone
Norethisterone, also known as norethindrone and sold under many brand names, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medication is available in b ...
in clinical studies
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 ...
.
Pharmacokinetics
Absorption
Surprisingly few studies have been conducted on the pharmacokinetics
Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...
of MPA at postmenopausal replacement dosages. The bioavailability of MPA with 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 ...
is approximately 100%. A single oral dose of 10 mg MPA has been found to result in peak MPA levels of 1.2 to 5.2 ng/mL within 2 hours of administration using radioimmunoassay. Following this, levels of MPA decreased to 0.09 to 0.35 ng/mL 12 hours post-administration. In another study, peak levels of MPA were 3.4 to 4.4 ng/mL within 1 to 4 hours of administration of 10 mg oral MPA using radioimmunoassay. Subsequently, MPA levels fell to 0.3 to 0.6 ng/mL 24 hours after administration. In a third study, MPA levels were 4.2 to 4.4 ng/mL after an oral dose of 5 mg MPA and 6.0 ng/mL after an oral dose of 10 mg MPA, both using radioimmunoassay as well.
Treatment of postmenopausal women with 2.5 or 5 mg/day MPA in combination with estradiol valerate for two weeks has been found to rapidly increase circulating MPA levels, with steady-state
In systems theory, a system or a process is in a steady state if the variables (called state variables) which define the behavior of the system or the process are unchanging in time. In continuous time, this means that for those properties '' ...
concentrations achieved after three days and peak concentrations occurring 1.5 to 2 hours after ingestion. With 2.5 mg/day MPA, levels of the medication were 0.3 ng/mL (0.8 nmol/L) in women under 60 years of age and 0.45 ng/mL (1.2 nmol/L) in women 65 years of age or over, and with 5 mg/day MPA, levels were 0.6 ng/mL (1.6 nmol/L) in women under 60 years of age and in women 65 years of age or over. Hence, area-under-curve levels of the medication were 1.6 to 1.8 times higher in those who were 65 years of age or older relative to those who were 60 years of age or younger. As such, levels of MPA have been found to vary with age, and MPA may have an increased risk of side effects in elderly postmenopausal women. This study assessed MPA levels using liquid-chromatography–tandem mass spectrometry (LC–MS/MS), a more accurate method of blood determinations.
Oral MPA tablets can be administered sublingually instead of orally. Rectal administration of MPA has also been studied.
With intramuscular administration
Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles have ...
of 150 mg microcrystalline
A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination. There is little agreement on the range of crystal sizes that should be regarded as microcrystalline, but the ...
MPA in aqueous suspension, the medication is detectable in the circulation within 30 minutes, serum concentrations vary but generally plateau at 1.0 ng/mL (2.6 nmol/L) for 3 months. Following this, there is a gradual decline in MPA levels, and the medication can be detected in the circulation for as long as 6 to 9 months post-injection. The particle size of MPA crystals significantly influences its rate of absorption into the body from the local tissue depot when used as a microcrystalline aqueous suspension via intramuscular injection. Smaller crystals dissolve faster and are absorbed more rapidly, resulting in a shorter duration of action. Particle sizes can differ between different formulations of MPA, potentially influencing clinical efficacy and tolerability.
Distribution
The plasma protein binding of MPA is 88%. It is weakly bound 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. Album ...
and is not bound to sex hormone-binding globulin or corticosteroid-binding globulin.
Metabolism
The elimination 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 b ...
of MPA via oral administration has been reported as both 11.6 to 16.6 hours and 33 hours, whereas the elimination half-lives with intramuscular
Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles ha ...
and subcutaneous injection
Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion.
A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, c ...
of microcrystalline MPA in aqueous suspension are 50 and 40 days, respectively. The 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 ...
of MPA is mainly via hydroxylation
In chemistry, hydroxylation can refer to:
*(i) most commonly, hydroxylation describes a chemical process that introduces a hydroxyl group () into an organic compound.
*(ii) the ''degree of hydroxylation'' refers to the number of OH groups in a ...
, including at positions C6β, C21, C2β, and C1β, mediated primarily via CYP3A4
Cytochrome P450 3A4 (abbreviated CYP3A4) () is an important enzyme in the body, mainly found in the liver and in the intestine. It oxidizes small foreign organic molecules ( xenobiotics), such as toxins or drugs, so that they can be removed from ...
, but 3- and 5-dihydro and 3,5-tetrahydro metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, ...
s of MPA are also formed. Deacetylation of MPA and its metabolites (into, e.g., medroxyprogesterone
Medroxyprogesterone (MP), is a progestin which is not used medically. A derivative, medroxyprogesterone acetate (MPA), is used as a medication in humans, and is far more widely known in comparison. ''Medroxyprogesterone'' is sometimes used as a ...
) has been observed to occur in non-human primate research to a substantial extent as well (30 to 70%). MPA and/or its metabolites are also metabolized via conjugation
Conjugation or conjugate may refer to:
Linguistics
*Grammatical conjugation, the modification of a verb from its basic form
* Emotive conjugation or Russell's conjugation, the use of loaded language
Mathematics
*Complex conjugation, the change ...
. The C6α methyl
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in ...
and C17α acetoxy groups of MPA make it more resistant to metabolism and allow for greater bioavailability than oral progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
.
Elimination
MPA is eliminated 20 to 50% in urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellul ...
and 5 to 10% in feces
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a rela ...
following intravenous administration. Less than 3% of a dose is excreted in unconjugated form.
Level–effect relationships
With intramuscular administration, the high levels of MPA in the blood inhibit luteinizing hormone and ovulation for several months, with an accompanying decrease in serum progesterone to below 0.4 ng/mL. Ovulation resumes when once blood levels of MPA fall below 0.1 ng/mL. Serum estradiol remains at approximately 50 pg/mL for approximately four months post-injection (with a range of 10–92 pg/mL after several years of use), rising once MPA levels fall below 0.5 ng/mL.
Hot flash
Hot flashes (also known as hot flushes) are a form of flushing, often caused by the changing hormone levels that are characteristic of menopause. They are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, an ...
es are rare while MPA is found at significant blood levels in the body, and the vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
l lining remains moist and creased. The endometrium
The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The functional layer ...
undergoes atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply ...
, with small, straight glands and a stroma that is decidualized. Cervical mucus
The cervix or cervix uteri (Latin, 'neck of the uterus') is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long (~1 inch) and roughly cylindrical in shape, which changes during ...
remains viscous
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the in ...
. Because of its steady blood levels over the long term and multiple effects that prevent fertilization
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Pro ...
, MPA is a very effective means of birth control
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth contr ...
.[
]
Time–concentration curves
Chemistry
MPA is a synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to:
Science
* Synthetic chemical or compound, produced by the process of chemical synthesis
* Synthetic ...
pregnane steroid
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and ...
and 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
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...
and 17α-hydroxyprogesterone. Specifically, it is the 17α-acetate
An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...
ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...
of medroxyprogesterone
Medroxyprogesterone (MP), is a progestin which is not used medically. A derivative, medroxyprogesterone acetate (MPA), is used as a medication in humans, and is far more widely known in comparison. ''Medroxyprogesterone'' is sometimes used as a ...
or the 6α- methylated analogue of hydroxyprogesterone acetate
Hydroxyprogesterone acetate (OHPA), sold under the brand name Prodox, is an orally active progestin related to hydroxyprogesterone caproate (OHPC) which has been used in clinical and veterinary medicine. It has reportedly also been used in bir ...
. MPA is known chemically as 6α-methyl-17α-acetoxyprogesterone or as 6α-methyl-17α-acetoxypregn-4-ene-3,20-dione, and its generic name is a contraction of 6α-methyl-17α-hydroxyprogesterone acetate. MPA is closely related to other 17α-hydroxyprogesterone derivatives such as chlormadinone acetate, cyproterone acetate, and megestrol acetate, as well as to medrogestone and nomegestrol acetate. 9α-fluoromedroxyprogesterone acetate (FMPA), the C9α fluoro
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactive, ...
analogue of MPA and an angiogenesis inhibitor with two orders of magnitude greater potency in comparison to MPA, was investigated for the potential treatment of cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
s but was never marketed.
History
MPA was independently discovered in 1956 by Syntex Laboratorios Syntex SA (later Syntex Laboratories, Inc.) was a pharmaceutical company formed in Mexico City in January 1944 by Russell Marker, Emeric Somlo, and Federico Lehmann to manufacture therapeutic steroids from the Mexican yams called ''cab ...
and the Upjohn Company
The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''friabl ...
. It was first introduced on 18 June 1959 by Upjohn 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 Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
under the brand name Provera (2.5, 5, and 10 mg tablets) for the treatment of amenorrhea, 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 occur ...
, and recurrent miscarriage
Recurrent miscarriage is three or more consecutive pregnancy losses. In contrast, infertility is the inability to conceive. In many cases the cause of RPL is unknown. After three or more losses, a thorough evaluation is recommended by American ...
. An intramuscular formulation of MPA, now known as DMPA (400 mg/mL MPA), was also introduced, under the brand name brand name Depo-Provera, in 1960 in the U.S. for the treatment of endometrial and renal cancer. MPA in combination with ethinylestradiol was introduced in 1964 by Upjohn in the U.S. under the brand name Provest (10 mg MPA and 50 μg ethinylestradiol tablets) as an oral contraceptive, but this formulation was discontinued in 1970. This formulation was marketed by Upjohn outside of the U.S. under the brand names Provestral and Provestrol, while Cyclo-Farlutal (or Ciclofarlutal) and Nogest-S were formulations available outside of the U.S. with a different dosage (5 mg MPA and 50 or 75 μg ethinylestradiol tablets).
Following its development in the late 1950s, DMPA was first assessed in clinical trials for use as an injectable contraceptive in 1963. Upjohn sought approval of intramuscular DMPA as a long-acting contraceptive under the brand name Depo-Provera (150 mg/mL MPA) in 1967, but the application was rejected. However, this formulation was successfully introduced in countries outside of the United States for the first time in 1969, and was available in over 90 countries worldwide by 1992. Upjohn attempted to gain FDA approval of DMPA as a contraceptive again in 1978, and yet again in 1983, but both applications failed similarly to the 1967 application. However, in 1992, the medication was finally approved by the FDA, under the brand name Depo-Provera, for use in contraception. A subcutaneous formulation of DMPA was introduced in the United States as a contraceptive under the brand name Depo-SubQ Provera 104 (104 mg/0.65 mL MPA) in December 2004, and subsequently was also approved for the treatment of endometriosis
Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fa ...
-related pelvic pain.
MPA has also been marketed widely throughout the world under numerous other brand names such as Farlutal, Perlutex, and Gestapuran, among others.
Society and culture
Generic names
''Medroxyprogesterone acetate'' is the generic name of the drug and its , , , and , while ''medrossiprogesterone'' is the and ''médroxyprogestérone'' the of its free alcohol form. It is also known as ''6α-methyl-17α-acetoxyprogesterone'' (''MAP'') or ''6α-methyl-17α-hydroxyprogesterone acetate''.
Brand names
MPA is marketed under a large number of brand names throughout the world. Its most major brand names are Provera as oral tablets and Depo-Provera as an aqueous suspension for intramuscular injection. A formulation of MPA as an aqueous suspension for subcutaneous injection is also available 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 Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
under the brand name Depo-SubQ Provera 104. Other brand names of MPA formulated alone include Farlutal and Sayana for clinical use and Depo-Promone, Perlutex, Promone-E, and Veramix for veterinary use. In addition to single-drug formulations, MPA is marketed in combination with the estrogens CEEs, estradiol, and estradiol valerate. Brand names of MPA in combination with CEEs as oral tablets in different countries include Prempro, Premphase, Premique, Premia, and Premelle. Brand names of MPA in combination with estradiol as oral tablets include Indivina and Tridestra.
Availability
Oral MPA and DMPA are widely available throughout the world. Oral MPA is available both alone and in combination with the estrogens CEEs, estradiol, and estradiol valerate. DMPA is registered for use as a form of birth control in more than 100 countries worldwide. The combination of injected MPA and estradiol cypionate is approved for use as a form of birth control in 18 countries.
United States
, MPA is available 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 Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
in the following formulations:
* Oral pills: Amen, Curretab, Cycrin, Provera – 2.5 mg, 5 mg, 10 mg
* Aqueous suspension for intramuscular injection: Depo-Provera – 150 mg/mL (for contraception), 400 mg/mL (for cancer)
* Aqueous suspension for subcutaneous injection: Depo-SubQ Provera 104 – 104 mg/0.65 mL (for contraception)
It is also available in combination with an estrogen in the following formulations:
* Oral pills: CEEs and MPA (Prempro, Prempro (Premarin, Cycrin), Premphase (Premarin, Cycrin 14/14), Premphase 14/14, Prempro/Premphase) – 0.3 mg / 1.5 mg; 0.45 mg / 1.5 mg; 0.625 mg / 2.5 mg; 0.625 mg / 5 mg
While the following formulations have been discontinued:
* Oral pills: ethinylestradiol and MPA (Provest) – 50 μg / 10 mg
* Aqueous suspension for intramuscular injection: estradiol cypionate and MPA (Lunelle) – 5 mg / 25 mg (for contraception)
The state of Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bord ...
permits sex offenders to be given MPA.
Generation
Progestins in birth control pills are sometimes grouped by generation. While the 19-nortestosterone
Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate (brand name Durabolin). Nandrolon ...
progestins are consistently grouped into generations, the pregnane progestins that are or have been used in birth control pills are typically omitted from such classifications or are grouped simply as "miscellaneous" or "pregnanes". In any case, based on its date of introduction in such formulations of 1964, MPA could be considered a "first-generation" progestin.
Controversy
Outside the United States
* In 1994, when DMPA was approved in India, India's ''Economic and Political Weekly'' reported that "The FDA finally licensed the drug in 1990 in response to concerns about the population explosion in the third world and the reluctance of third world governments to license a drug not licensed in its originating country." Some scientists and women's groups in India continue to oppose DMPA. In 2016, India introduced DMPA depo-medroxyprogesterone IM preparation in the public health system.
* The Canadian Coalition on Depo-Provera, a coalition of women's health professional and advocacy groups, opposed the approval of DMPA in Canada. Since the approval of DMPA in Canada in 1997, a $700 million class-action lawsuit
A class action, also known as a class-action lawsuit, class suit, or representative action, is a type of lawsuit where one of the parties is a group of people who are represented collectively by a member or members of that group. The class actio ...
has been filed against Pfizer by users of DMPA who developed osteoporosis
Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and consequent increase in fracture risk. It is the most common reason for a broken bone a ...
. In response, Pfizer argued that it had met its obligation to disclose and discuss the risks of DMPA with the Canadian medical community.
* Clinical trials for this medication regarding women in Zimbabwe
Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
were controversial with regard to human rights abuses and Medical Experimentation in Africa.
* A controversy erupted in Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
when the government was accused of giving DMPA to Ethiopian immigrants without their consent. Some women claimed they were told it was a vaccination. The Israeli government denied the accusations but instructed the four health maintenance organizations to stop administering DMPA injections to women "if there is the slightest doubt that they have not understood the implications of the treatment".
United States
There was a long, controversial history regarding the approval of DMPA by the U.S. Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
. The original manufacturer, Upjohn
The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''fria ...
, applied repeatedly for approval. FDA advisory committees unanimously recommended approval in 1973, 1975 and 1992, as did the FDA's professional medical staff, but the FDA repeatedly denied approval. Ultimately, on 29 October 1992, the FDA approved DMPA for birth control, which had by then been used by over 30 million women since 1969 and was approved and being used by nearly 9 million women in more than 90 countries, including 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 continental mainland. It comprises England, Scotland, Wales and ...
, France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
, Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...
, Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...
, Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...
, 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 coun ...
and Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Gui ...
. Points in the controversy included:
* Animal testing for carcinogenicity – DMPA caused breast cancer tumors in dogs. Critics of the study claimed that dogs are more sensitive to artificial progesterone, and that the doses were too high to extrapolate to humans. The FDA pointed out that all substances carcinogenic to humans are carcinogenic to animals as well, and that if a substance is not carcinogenic it does not register as a carcinogen at high doses. Levels of DMPA which caused malignant mammary tumors in dogs were equivalent to 25 times the amount of the normal luteal phase progesterone level for dogs. This is lower than the pregnancy level of progesterone for dogs, and is species-specific.
DMPA caused endometrial cancer in monkeys – 2 of 12 monkeys tested, the first ever recorded cases of endometrial cancer in rhesus monkeys
The rhesus macaque (''Macaca mulatta''), colloquially rhesus monkey, is a species of Old World monkey. There are between six and nine recognised subspecies that are split between two groups, the Chinese-derived and the Indian-derived. Generally ...
. However, subsequent studies have shown that in humans, DMPA ''reduces'' the risk of endometrial cancer by approximately 80%.
Speaking in comparative terms regarding animal studies of carcinogenicity for medications, a member of the FDA's Bureau of Drugs testified at an agency DMPA hearing, "...Animal data for this drug is more worrisome than any other drug we know of that is to be given to well people."
* Cervical cancer in Upjohn/NCI studies. Cervical cancer was found to be increased as high as 9-fold in the first human studies recorded by the manufacturer and the National Cancer Institute
The National Cancer Institute (NCI) coordinates the United States National Cancer Program and is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. T ...
. However, numerous larger subsequent studies have shown that DMPA use does not increase the risk of cervical cancer.
* Coercion and lack of informed consent. Testing or use of DMPA was focused almost exclusively on women in developing countries
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...
and poor women in the United States, raising serious questions about coercion and lack of informed consent, particularly for the illiterate and for mentally disabled people, who in some reported cases were given DMPA long-term for reasons of "menstrual hygiene", although they were not sexually active.
* Atlanta/Grady Study – Upjohn studied the effect of DMPA for 11 years in Atlanta, mostly on black women who were receiving public assistance, but did not file any of the required follow-up reports with the FDA. Investigators who eventually visited noted that the studies were disorganized. "They found that data collection was questionable, consent forms and protocol were absent; that those women whose consent had been obtained at all were not told of possible side effects. Women whose known medical conditions indicated that use of DMPA would endanger their health were given the shot. Several of the women in the study died; some of cancer, but some for other reasons, such as suicide due to depression. Over half the 13,000 women in the study were lost to followup due to sloppy record keeping." Consequently, no data from this study was usable.
* WHO Review – In 1992, the WHO presented a review of DMPA in four developing countries to the FDA. The National Women's Health Network
The National Women's Health Network (NWHN) is a non-profit women's health advocacy organization located in Washington, D.C. It was founded in 1975 by Barbara Seaman, Alice Wolfson, Belita Cowan, Mary Howell, and Phyllis Chesler. The stated mission ...
and other women's organizations testified at the hearing that the WHO was not objective, as the WHO had already distributed DMPA in developing countries. DMPA was approved for use in United States on the basis of the WHO review of previously submitted evidence from countries such as Thailand, evidence which the FDA had deemed insufficient and too poorly designed for assessment of cancer risk at a prior hearing.
* The Alan Guttmacher Institute has speculated that United States approval of DMPA may increase its availability and acceptability in developing countries.
* In 1995, several women's health groups asked the FDA to put a moratorium on DMPA, and to institute standardized informed consent forms.
Research
DMPA was studied by Upjohn
The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''fria ...
for use as a progestogen-only injectable contraceptive in women at a dose of 50 mg once a month but produced poor cycle control and was not marketed for this use at this dosage. A combination of DMPA and polyestradiol phosphate
Polyestradiol phosphate (PEP), sold under the brand name Estradurin, is an estrogen medication which is used primarily in the treatment of prostate cancer in men. It is also used in women to treat breast cancer, as a component of hormone therapy ...
, 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 long-lasting prodrug
A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the dru ...
of estradiol, was studied in women as a combined injectable contraceptive
Combined injectable contraceptives (CICs) are a form of hormonal birth control for women. They consist of monthly injections of combined formulations containing an estrogen and a progestin to prevent pregnancy.
CICs are different from progestoge ...
for use by intramuscular injection
Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...
once every three months.
High-dose oral and intramuscular MPA monotherapy has been studied in the treatment of prostate cancer but was found to be inferior to monotherapy with cyproterone acetate or diethylstilbestrol
Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with ...
. High-dose oral MPA has been studied in combination with diethylstilbestrol and CEEs as an addition to high-dose estrogen
High-dose estrogen (HDE) is a type of hormone therapy in which high doses of estrogens are given. When given in combination with a high dose of a progestogen, it has been referred to as pseudopregnancy. It is called this because the estrogen and p ...
therapy for the treatment of prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that su ...
in men, but was not found to provide better effectiveness than diethylstilbestrol alone.
DMPA has been studied for use as a potential male hormonal contraceptive in combination with the androgens/anabolic steroid
Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects ...
s 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 nandrolone (19-nortestosterone) in men. However, it was never approved for this indication.
MPA was investigated by InKine Pharmaceutical, Salix Pharmaceuticals, and the University of Pennsylvania
The University of Pennsylvania (also known as Penn or UPenn) is a Private university, private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest- ...
as a potential anti-inflammatory medication for the treatment of autoimmune hemolytic anemia
Autoimmune hemolytic anemia (AIHA) occurs when antibodies directed against the person's own red blood cells (RBCs) cause them to burst (lyse), leading to an insufficient number of oxygen-carrying red blood cells in the circulation. The lifetime of ...
, Crohn's disease
Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distensi ...
, idiopathic thrombocytopenic purpura
Immune thrombocytopenic purpura (ITP), also known as idiopathic thrombocytopenic purpura or immune thrombocytopenia, is a type of thrombocytopenic purpura defined as an isolated low platelet count with a normal bone marrow in the absence of oth ...
, and ulcerative colitis, but did not complete clinical development and was never approved for these indications. It was formulated as an oral medication at very high dosages, and was thought to inhibit the signaling of proinflammatory cytokine An inflammatory cytokine or proinflammatory cytokine is a type of signaling molecule (a cytokine) that is secreted from immune cells like helper T cells (Th) and macrophages, and certain other cell types that promote inflammation. They include inte ...
s such as interleukin 6 and tumor necrosis factor alpha
Tumor necrosis factor (TNF, cachexin, or cachectin; formerly known as tumor necrosis factor alpha or TNF-α) is an adipokine and a cytokine. TNF is a member of the TNF superfamily, which consists of various transmembrane proteins with a homolo ...
, with a mechanism of action that was said to be similar to that of corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are inv ...
s. The formulation of MPA had the tentative brand names Colirest and Hematrol for these indications.
MPA has been found to be effective in the treatment of manic symptoms in women with bipolar disorder
Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of Depression (mood), depression and periods of abnormally elevated Mood (psychology), mood that last from days to weeks each. If the elevat ...
.
Veterinary use
MPA has been used to reduce aggression
Aggression is overt or covert, often harmful, social interaction with the intention of inflicting damage or other harm upon another individual; although it can be channeled into creative and practical outlets for some. It may occur either reacti ...
and spraying in male cats. It may be particularly useful for controlling such behaviors in neutered male cats. The medication can be administered in cats as an injection once per month.
See also
* Conjugated estrogens/medroxyprogesterone acetate
* Estradiol/medroxyprogesterone acetate
* Estradiol cypionate/medroxyprogesterone acetate
* Polyestradiol phosphate/medroxyprogesterone acetate
References
External links
*
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