A gonadotropin-releasing hormone agonist (GnRH agonist) is a type of medication which affects
gonadotropin
Gonadotropins are glycoprotein hormones secreted by gonadotropic cells of the anterior pituitary of vertebrates. This family includes the mammalian hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH), the placental/ chorioni ...
s and
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 ...
s.
They are used for a variety of indications including in
fertility medicine
Reproductive endocrinology and infertility (REI) is a surgical subspecialty of obstetrics and gynecology that trains physicians in reproductive medicine addressing hormonal functioning as it pertains to reproduction as well as the issue of in ...
and to lower sex hormone levels in the treatment of
hormone-sensitive cancer
A hormone-sensitive cancer, or hormone-dependent cancer, is a type of cancer that is dependent on a hormone for growth and/or survival. Examples include breast cancer, which is dependent on estrogens like estradiol, and prostate cancer, which is ...
s such as
prostate 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 a r ...
, certain
gynecological disorder
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 area ...
s like
heavy periods and
endometriosis,
high testosterone levels in women,
early puberty
In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. In a minority of childr ...
in children, as a part of
transgender hormone therapy
Transgender hormone therapy, also called hormone replacement therapy (HRT) or gender-affirming hormone therapy (GAHT), is a form of hormone therapy in which sex hormones and other hormonal medications are administered to transgender or gender non ...
, and to
delay puberty in
transgender youth
Transgender youth are children or adolescents who do not identify with the sex they were assigned at birth. Because transgender youth are usually dependent on their parents for care, shelter, financial support, and other needs, transgender yo ...
among other uses. GnRH agonists are given by
injections into fat, as
implants placed into fat, and as
nasal spray
Nasal sprays are used to deliver medications locally in the nasal cavities or systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some situations, the nasal delivery route is preferred for syst ...
s.
Side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s of GnRH agonists are related to
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 ...
deficiency
A deficiency is generally a lack of something. It may also refer to:
*A deficient number, in mathematics, a number ''n'' for which ''σ''(''n'') < 2''n''
* and include
symptoms of
low testosterone levels and
low estrogen levels 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, and ...
es,
sexual dysfunction
Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction a ...
,
vaginal atrophy,
penile atrophy,
osteoporosis,
infertility, and diminished
sex-specific physical characteristics. They are
agonists of the
GnRH receptor
The gonadotropin-releasing hormone receptor (GnRHR), also known as the luteinizing hormone releasing hormone receptor (LHRHR), is a member of the seven-transmembrane, G-protein coupled receptor (GPCR) family. It is the receptor of gonadotropin ...
and work by increasing or decreasing the
release
Release may refer to:
* Art release, the public distribution of an artistic production, such as a film, album, or song
* Legal release, a legal instrument
* News release, a communication directed at the news media
* Release (ISUP), a code to iden ...
of gonadotropins and the
production
Production may refer to:
Economics and business
* Production (economics)
* Production, the act of manufacturing goods
* Production, in the outline of industrial organization, the act of making products (goods and services)
* Production as a stati ...
of sex hormones by the
gonads. When used to suppress gonadotropin release, GnRH agonists can lower sex hormone levels by 95% in both sexes.
GnRH was discovered in 1971, and GnRH analogues were introduced for medical use in the 1980s.
Their nonproprietary names usually end in ''-relin''. The most well-known and widely used GnRH analogues are
leuprorelin
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, as part of transgender hormone therapy, for early puberty, or to perform chemical cas ...
(brand name Lupron) and
triptorelin
Triptorelin, sold under the brand name Decapeptyl among others, is a medication that acts as an agonist analog of gonadotropin-releasing hormone, repressing expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
It is a ...
(brand name Decapeptyl). GnRH analogues are available as
generic medications. Despite this, they continue to be very expensive.
Medical uses
GnRH agonists are useful in:
*
Suppression of spontaneous ovulation as part of
controlled ovarian hyperstimulation Controlled ovarian hyperstimulation is a technique used in assisted reproduction involving the use of fertility medications to induce ovulation by multiple ovarian follicles. These multiple follicles can be taken out by oocyte retrieval (egg col ...
, which is an essential component in
''in vitro'' fertilisation (IVF). Typically, after GnRH agonists have induced a state of hypoestrogenism, exogenous FSH is given to stimulate ovarian follicle, followed by
human chorionic gonadotropin
Human chorionic gonadotropin (hCG) is a hormone for the maternal recognition of pregnancy produced by trophoblast cells that are surrounding a growing embryo (syncytiotrophoblast initially), which eventually forms the placenta after implantatio ...
s (hCG) to
trigger oocyte release. GnRH agonists routinely used for this purpose are: buserelin, leuprorelin, nafarelin, and triptorelin.
*
Final maturation induction Induction of final maturation of oocytes is a procedure that is usually performed as part of controlled ovarian hyperstimulation to render the oocytes fully developed and thereby resulting in optimal pregnancy chances. It is basically a replacement ...
after having performed controlled ovarian hyperstimulation. Usage of GnRH agonist for this purpose necessitates using a
GnRH antagonist
Gonadotropin-releasing hormone antagonists (GnRH antagonists) are a class of medications that antagonize the gonadotropin-releasing hormone receptor (GnRH receptor) and thus the action of gonadotropin-releasing hormone (GnRH). They are used in ...
instead of a GnRH agonist for
suppression of spontaneous ovulation, because using GnRH agonist for that purpose as well inactivates the axis for which it is intended to work for final maturation induction.
* 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 that are hormonally sensitive and where a hypogonadal state decreases the chances of a recurrence. Thus they are commonly employed in the medical management of
prostate cancer and have been used in patients with
breast cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a r ...
.
* Delaying puberty in individuals with
precocious puberty
In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. In a minority of childr ...
.
*
Delaying puberty pending treatment decisions in children with
gender dysphoria.
* Management of female disorders that are dependent on
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 ...
production. Women with
menorrhagia,
endometriosis,
adenomyosis, or
uterine fibroid
Uterine fibroids, also known as uterine leiomyomas or fibroids, are benign smooth muscle tumors of the uterus. Most women with fibroids have no symptoms while others may have painful or heavy periods. If large enough, they may push on the bl ...
s may receive GnRH agonists to suppress ovarian activity and induce a hypoestrogenic state.
* Suppressing sex hormone levels in
transgender people
This list consists of many notable people who are transgender. The individual listings note the subject's nationality and main occupation.
In some non-Western, ancient or medieval societies, transgender people may be seen as a different gend ...
, especially
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 ...
.
* Severe cases of
hyperandrogenism
Hyperandrogenism is a medical condition characterized by high levels of androgens. It is more common in women than men. Symptoms of hyperandrogenism may include acne, seborrhea (inflamed skin), hair loss on the scalp, increased body or facia ...
, such as in
congenital adrenal hyperplasia
Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by impaired cortisol synthesis. It results from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cort ...
.
* As part of the pharmacologic treatment of
paraphilic
Paraphilia (previously known as sexual perversion and sexual deviation) is the experience of intense sexual arousal to atypical objects, situations, fantasies, behaviors, or individuals. It has also been defined as sexual interest in anything ot ...
disorders in sexual offenders or men with a high risk of sexual offending.
Women of reproductive age who undergo cytotoxic
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
have been pretreated with GnRH agonists to reduce the risk of oocyte loss during such therapy and preserve ovarian function. Further studies are necessary to prove that this approach is useful.
Available forms
GnRH agonists that have been marketed and are available for medical use include
buserelin
Buserelin, sold under the brand name Suprefact among others, is a medication which is used primarily in the treatment of prostate cancer and endometriosis. It is also used for other indications such as the treatment of premenopausal breast cance ...
,
gonadorelin
Gonadorelin is a gonadotropin-releasing hormone agonist (GnRH agonist) which is used in fertility medicine and to treat amenorrhea and hypogonadism. It is also used in veterinary medicine. The medication is a form of the endogenous GnRH and is i ...
,
goserelin
Goserelin, sold under the brand name Zoladex among others, is a medication which is used to suppress production of the sex hormones (testosterone and estrogen), particularly in the treatment of breast and prostate cancer. It is an injectable gon ...
,
histrelin,
leuprorelin
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, as part of transgender hormone therapy, for early puberty, or to perform chemical cas ...
,
nafarelin, and
triptorelin
Triptorelin, sold under the brand name Decapeptyl among others, is a medication that acts as an agonist analog of gonadotropin-releasing hormone, repressing expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
It is a ...
. GnRH agonists that are used mostly or exclusively 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 ...
include
deslorelin
Deslorelin, sold under the brand names Ovuplant, SucroMate, and Suprelorin among others, is an injectable gonadotropin releasing hormone superagonist (GnRH agonist) which is used in veterinary medicine for various indications.
Uses
Veterinary
...
and
fertirelin
Fertirelin, or fertirelin acetate, sold under the brand name Ovalyse, is a gonadotropin-releasing hormone agonist (GnRH agonist) which has been marketed in the United Kingdom and Austria. It may no longer be available. Fertirelin has been used in ...
. GnRH agonists can be administered by
injection
Injection or injected may refer to:
Science and technology
* Injective function, a mathematical function mapping distinct arguments to distinct values
* Injection (medicine), insertion of liquid into the body with a syringe
* Injection, in broadca ...
, by
implant, or
intranasally as a
nasal spray
Nasal sprays are used to deliver medications locally in the nasal cavities or systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some situations, the nasal delivery route is preferred for syst ...
. Injectables have been formulated for daily, monthly, and quarterly use, and implants are available that can last from one month to a year. With the exception of gonadorelin, which is used as a
progonadotropin
A progonadotropin, or hypergonadotropin, also known as a gonad stimulant, is a type of drug which increases the secretion of one or both of the major gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This, in turn, re ...
, all approved GnRH agonists are used as
antigonadotropin
An antigonadotropin is a drug which suppresses the activity and/or downstream effects of one or both of the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This results in an inhibition of the hypothalamic-pitui ...
s.
The clinically used desensitizing GnRH agonists are available in the following
pharmaceutical formulation
Pharmaceutical formulation, in pharmaceutics, is the process in which different chemical substances, including the active drug, are combined to produce a final medicinal product. The word ''formulation'' is often used in a way that includes dosage ...
s:
* Short-acting injection (once per day):
buserelin
Buserelin, sold under the brand name Suprefact among others, is a medication which is used primarily in the treatment of prostate cancer and endometriosis. It is also used for other indications such as the treatment of premenopausal breast cance ...
,
histrelin,
leuprorelin
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, as part of transgender hormone therapy, for early puberty, or to perform chemical cas ...
,
triptorelin
Triptorelin, sold under the brand name Decapeptyl among others, is a medication that acts as an agonist analog of gonadotropin-releasing hormone, repressing expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
It is a ...
* Long-acting depot injection or injected pellet (once every one to six months):
leuprorelin
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, as part of transgender hormone therapy, for early puberty, or to perform chemical cas ...
,
triptorelin
Triptorelin, sold under the brand name Decapeptyl among others, is a medication that acts as an agonist analog of gonadotropin-releasing hormone, repressing expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
It is a ...
* Injected implant (once every one to three months):
buserelin
Buserelin, sold under the brand name Suprefact among others, is a medication which is used primarily in the treatment of prostate cancer and endometriosis. It is also used for other indications such as the treatment of premenopausal breast cance ...
,
goserelin
Goserelin, sold under the brand name Zoladex among others, is a medication which is used to suppress production of the sex hormones (testosterone and estrogen), particularly in the treatment of breast and prostate cancer. It is an injectable gon ...
,
leuprorelin
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, as part of transgender hormone therapy, for early puberty, or to perform chemical cas ...
* Surgically implanted pellet (once per year):
histrelin,
leuprorelin
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, as part of transgender hormone therapy, for early puberty, or to perform chemical cas ...
* Nasal spray (two to three times per day):
buserelin
Buserelin, sold under the brand name Suprefact among others, is a medication which is used primarily in the treatment of prostate cancer and endometriosis. It is also used for other indications such as the treatment of premenopausal breast cance ...
,
nafarelin
Contraindications
GnRH agonists are
pregnancy category
The pregnancy category of a medication is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. It does ''not'' include any risks conferred by pharmaceutical agents or their ...
X drugs.
Side effects
Common side effects of the GnRH agonists and antagonists include symptoms of hypogonadism such as hot flashes, gynecomastia, fatigue, weight gain, fluid retention, erectile dysfunction and decreased libido. Long term therapy can result in metabolic abnormalities, weight gain, worsening of diabetes and osteoporosis. Rare, but potentially serious adverse events include transient worsening of prostate cancer due to surge in testosterone with initial injection of GnRH agonists and pituitary apoplexy in patients with pituitary adenoma. Single instances of clinically apparent liver injury have been reported with some GnRH agonists (histrelin, goserelin), but the reports were not very convincing. There is no evidence to indicate that there is cross sensitivity to liver injury among the various GnRH analogues despite their similarity in structure.
There is also a report that GnRH agonists used in the treatment of advanced
prostate cancer may increase the risk of heart problems by 30%.
Pharmacology
GnRH agonists act as
agonists of the
GnRH receptor
The gonadotropin-releasing hormone receptor (GnRHR), also known as the luteinizing hormone releasing hormone receptor (LHRHR), is a member of the seven-transmembrane, G-protein coupled receptor (GPCR) family. It is the receptor of gonadotropin ...
, the
biological target
A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets ...
of
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 release ...
(GnRH). These drugs can be both
peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides.
...
s and
small-molecule
Within the fields of molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs ar ...
s. They are modeled after the
hypothalamic
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 i ...
neurohormone A neurohormone is any hormone produced and released by neuroendocrine cells (also called neurosecretory cells) into the blood. By definition of being hormones, they are secreted into the circulation for systemic effect, but they can also have a role ...
GnRH, which interacts with the GnRH receptor to elicit its biologic response, the release of the
pituitary
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 hypoph ...
hormone
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are require ...
s
follicle-stimulating hormone (FSH) and
luteinizing hormone
Luteinizing hormone (LH, also known as luteinising hormone, lutropin and sometimes lutrophin) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) ...
(LH). However, after the initial "flare" response, continued stimulation with GnRH agonists desensitizes the pituitary gland (by causing GnRH receptor downregulation) to GnRH. Pituitary desensitization reduces the secretion of LH and FSH and thus induces a state of hypogonadotropic hypogonadal anovulation, sometimes referred to as "pseudomenopause" or "medical oophorectomy."
GnRH agonists are able to completely shutdown gonadal testosterone production and thereby suppress circulating testosterone levels by 95% or into the castrate/female range in men.
Agonists do not quickly dissociate from the GnRH receptor. As a result, initially there is an increase in FSH and LH secretion (so-called "flare effect"). Levels of LH may increase by up to 10-fold,
while levels of testosterone generally increase to 140 to 200% of baseline values.
However, after continuous administration, a profound hypogonadal effect (i.e. decrease in FSH and LH) is achieved through receptor
downregulation
In the biological context of organisms' production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. The complementary pr ...
by internalization of receptors.
Generally this induced and reversible
hypogonadism
Hypogonadism means diminished functional activity of the gonads—the testes or the ovaries—that may result in diminished production of sex hormones. Low androgen (e.g., testosterone) levels are referred to as hypoandrogenism and low estroge ...
is the therapeutic goal. During the flare, peak levels of testosterone occur after 2 to 4 days, baseline testosterone levels are returned to by 7 to 8 days, and castrate levels of testosterone are achieved by 2 to 4 weeks.
Following the cessation of exogenous GnRH agonists, it takes 5 to 8 days before normal gonadotropin secretion is completely restored.
Various medications can be used to prevent the testosterone flare and/or its effects at the initiation of GnRH agonist therapy.
These include
antigonadotropin
An antigonadotropin is a drug which suppresses the activity and/or downstream effects of one or both of the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This results in an inhibition of the hypothalamic-pitui ...
s such as
progestogens like
cyproterone acetate
Cyproterone acetate (CPA), sold alone under the brand name Androcur or with ethinylestradiol under the brand names Diane or Diane-35 among others, is an antiandrogen and progestin medication used in the treatment of androgen-dependent condition ...
and
chlormadinone acetate
Chlormadinone acetate (CMA), sold under the brand names Belara, Gynorelle, Lutéran, and Prostal among others, is a progestin and antiandrogen medication which is used in birth control pills to prevent pregnancy, as a component of menopausal hor ...
and
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 like
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 a ...
,
fosfestrol
Fosfestrol, sold under the brand name Honvan and also known as diethylstilbestrol diphosphate (DESDP), is an estrogen medication which is used in the treatment of prostate cancer in men. It is given by slow intravenous infusion once per day to on ...
(diethylstilbestrol diphosphate), and
estramustine phosphate
Estramustine phosphate (EMP), also known as estradiol normustine phosphate and sold under the brand names Emcyt and Estracyt, is a dual estrogen and chemotherapy medication which is used in the treatment of prostate cancer in men. It is taken ...
;
antiandrogen
Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the ...
s such as
nonsteroidal antiandrogen
A nonsteroidal antiandrogen (NSAA) is an antiandrogen with a nonsteroidal chemical structure. They are typically selective and full or silent antagonists of the androgen receptor (AR) and act by directly blocking the effects of androgens like ...
s like
flutamide
Flutamide, sold under the brand name Eulexin among others, is a nonsteroidal antiandrogen (NSAA) which is used primarily to treat prostate cancer. It is also used in the treatment of androgen-dependent conditions like acne, excessive hair grow ...
,
nilutamide
Nilutamide, sold under the brand names Nilandron and Anandron, is a nonsteroidal antiandrogen (NSAA) which is used in the treatment of prostate cancer.https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/020169s008lbl.pdf It has also been ...
, and
bicalutamide
Bicalutamide, sold under the brand name Casodex among others, is an antiandrogen medication that is primarily used to treat prostate cancer. It is typically used together with a gonadotropin-releasing hormone (GnRH) analogue or surgical remo ...
; and
androgen synthesis inhibitor An androgen synthesis inhibitor is a type of drug which inhibits the enzymatic synthesis of androgens, such as testosterone and dihydrotestosterone (DHT). They include:
* CYP17A1 inhibitors (17α-hydroxylase/17,20-lyase inhibitors): inhibit the s ...
s such as
ketoconazole and
abiraterone acetate
Abiraterone acetate, sold under the brand name Zytiga among others, is a medication used to treat prostate cancer. Specifically it is used together with a corticosteroid for metastasis, metastatic Prostate cancer#Castration-resistant cancer, ca ...
.
Chemistry
GnRH agonists are synthetically modeled after the natural GnRH decapeptide with specific modifications, usually double and single substitutions and typically in position 6 (amino acid substitution), 9 (alkylation) and 10 (deletion). These substitutions inhibit rapid degradation. Agonists with two substitutions include:
leuprorelin
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, as part of transgender hormone therapy, for early puberty, or to perform chemical cas ...
,
buserelin
Buserelin, sold under the brand name Suprefact among others, is a medication which is used primarily in the treatment of prostate cancer and endometriosis. It is also used for other indications such as the treatment of premenopausal breast cance ...
,
histrelin,
goserelin
Goserelin, sold under the brand name Zoladex among others, is a medication which is used to suppress production of the sex hormones (testosterone and estrogen), particularly in the treatment of breast and prostate cancer. It is an injectable gon ...
, and
deslorelin
Deslorelin, sold under the brand names Ovuplant, SucroMate, and Suprelorin among others, is an injectable gonadotropin releasing hormone superagonist (GnRH agonist) which is used in veterinary medicine for various indications.
Uses
Veterinary
...
. The agents
nafarelin and
triptorelin
Triptorelin, sold under the brand name Decapeptyl among others, is a medication that acts as an agonist analog of gonadotropin-releasing hormone, repressing expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
It is a ...
are agonists with single substitutions at position 6.
Veterinary uses
GnRH analogues are also used 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 ...
. Uses include:
* Temporary suppression of fertility in female dogs
* Induction of ovulation in mares
See also
*
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 release ...
*
Gonadotropin-releasing hormone antagonist
Gonadotropin-releasing hormone antagonists (GnRH antagonists) are a class of medications that antagonize the gonadotropin-releasing hormone receptor (GnRH receptor) and thus the action of gonadotropin-releasing hormone (GnRH). They are used in ...
*
Progonadotropin
A progonadotropin, or hypergonadotropin, also known as a gonad stimulant, is a type of drug which increases the secretion of one or both of the major gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This, in turn, re ...
References
External links
Buserelin websiteLupron, by manufacturer10th International Symposium on GnRHSupprelinLA, by Endo Pharmaceuticals, Inc.Information of use of Zoladex in prostate cancer
{{DEFAULTSORT:Gonadotropin-Releasing Hormone Agonist
Antiandrogens
Antiestrogens
Antigonadotropins
Fertility medicine
Hormonal antineoplastic drugs
Gonadotropin-releasing hormone and gonadotropins
Progonadotropins