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Antiprogestogen
Antiprogestogens or antiprogestins, also known as progesterone antagonists or progesterone blockers, are a class of drugs which prevent progestogens like progesterone from mediating their biological effects in the body. These drugs competitively inhibit progestin at progesterone receptors, acting by blocking the progesterone receptor (PR) and/or inhibiting or suppressing progestogen production. Antiprogestogens are one of three types of sex hormone antagonists, alongside antiestrogens and antiandrogens. Clinical applications Antiprogestogens are used as abortifacients, emergency contraceptives, and in the treatment of uterine fibroids. They are also being studied in the treatment of breast cancer. Examples include the progesterone receptor weak partial agonist In pharmacology, partial agonists are drugs that bind to and activate a given Receptor (biochemistry), receptor, but have only partial Intrinsic activity, efficacy at the receptor relative to a full ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mifepristone
Mifepristone, and also known by its developmental code name RU-486, is a drug typically used in combination with misoprostol to bring about a medical abortion during pregnancy. This combination is 97% effective during the first 63 days (9 weeks) of pregnancy, yet effective in the second trimester as well. It is also used on its own to treat Cushing's syndrome or for use as a low-dose Emergency contraception, emergency contraceptive. The most common adverse effects include abdominal pain, feeling tired, and vaginal bleeding. Serious side effects may include heavy vaginal bleeding, bacterial infection, and, if pregnant, birth defects. When used, appropriate follow-up care needs to be available. Mifepristone is primarily an antiprogestogen. It works by blocking the effects of progesterone, making both the cervix and uterine vessels dilate and causing uterine contraction. Mifepristone also works, to a less extent, as an antiglucocorticoid and diminishes the effects of hypercortis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onapristone
Onapristone () (developmental code names ZK-89299, ZK-299) is a synthetic and steroidal antiprogestogen with additional antiglucocorticoid activity which was developed by Schering and described in 1984 but was never marketed. It is a silent antagonist of the progesterone receptor (PR), in contrast to the related antiprogestogen mifepristone (which is a weak partial agonist of the receptor). Moreover, compared to mifepristone, onapristone has reduced antiglucocorticoid activity, shows little antiandrogenic activity, and has 10- to 30-fold greater potency as an antiprogestogen. The medication was under development for clinical use, for instance in the treatment of breast cancer and as an endometrial contraceptive, but was discontinued during phase III clinical trials in 1995 due to findings that liver function abnormalities developed in a majority patients. Onapristone has been found to be effective in the treatment of breast cancer. As of 2016, onapristone has re-emerg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aglepristone
Aglepristone () (brand name Alizin; former developmental code names RU-46534, RU-534) is a synthetic, steroidal antiprogestogen related to mifepristone which is marketed by Virbac in several European countries for use in veterinary medicine. It is specifically used as an abortifacient in pregnant animals. Aglepristone, similarly to mifepristone, also possesses some antiglucocorticoid activity. See also * Lilopristone * Onapristone Onapristone () (developmental code names ZK-89299, ZK-299) is a synthetic and steroidal antiprogestogen with additional antiglucocorticoid activity which was developed by Schering and described in 1984 but was never marketed. It is a sile ... * Telapristone * Toripristone References Abortifacients Alkene derivatives Dimethylamino compounds Antiglucocorticoids Antiprogestogens Estranes Enones Theriogenology Veterinary drugs {{steroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progesterone Receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene residing on chromosome 11q22, it has two isoforms, PR-A and PR-B, that differ in their molecular weight. The PR-B is the positive regulator of the effects of progesterone, while PR-A serve to antagonize the effects of PR-B. Mechanism Progesterone is necessary to induce activation of the progesterone receptors. When no binding hormone is present the carboxyl terminal inhibits transcription. Binding to a hormone induces a structural change that removes the inhibitory action. Progesterone antagonists prevent the structural reconfiguration. After progesterone binds to the receptor, restructuring with dimerization follows and the complex enters the nucleus and binds to DNA. There transcription takes place, resulting in formation of messenge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lilopristone
Lilopristone (INN; development codes ZK-98734 and ZK-734) is a synthetic, steroidal antiprogestogen with additional antiglucocorticoid activity which was developed by Schering and was patented in 1985. It is described as an abortifacient and endometrial contraceptive. The drug differs from mifepristone only in the structure of its C17α side chain, and is said to have much reduced antiglucocorticoid activity in comparison. See also * Aglepristone * Onapristone Onapristone () (developmental code names ZK-89299, ZK-299) is a synthetic and steroidal antiprogestogen with additional antiglucocorticoid activity which was developed by Schering and described in 1984 but was never marketed. It is a sile ... * Telapristone * Toripristone References Further reading * * Abortifacients Alkene derivatives Dimethylamino compounds Antiglucocorticoids Antiprogestogens Estranes Enones Conjugated dienes {{genito-urinary-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulipristal Acetate
Ulipristal acetate, sold under the brand name Ella among others, is a medication used for emergency contraception (birth control) and uterine fibroids. As emergency contraception it should be used within 120 hours of vaginally penetrating intercourse. For fibroids it may be taken for up to six months. It is taken Oral administration, by mouth. Common side effects include headache, nausea, feeling tired, and abdominal pain. It should not be used in women who are already pregnant. It is in the selective progesterone receptor modulator (SPRM) class of medications. It works by preventing the effects of progesterone, therefore preventing ovulation but not affecting Fertilisation, fertilization or Implantation (embryology), implantation. Ulipristal acetate was approved for medical use in the United States in 2010. It is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. Medical uses Emergency contraception For emergency contrac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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-pituitary-gonadal (HPG) axis, and thus a decrease in the levels of the androgen, estrogen, and progestogen sex steroids in the body. Antigonadotropins also inhibit ovulation in women and spermatogenesis in men. They are used for a variety of purposes, including for the hormonal birth control, treatment of hormonally-sensitive cancers, to delay precocious puberty and puberty in transgender youth, as a form of chemical castration to reduce the sex drives of individuals with hypersexuality or pedophilia, and to treat estrogen-associated conditions in women such as menorrhagia and endometriosis, among others. High-dose antigonadotropin therapy has been referred to as ''medical castration''. The best-known and widely used antigonadotropins are the g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex-hormonal Agent
__NOTOC__ A sex-hormonal agent, also known as a sex-hormone receptor modulator, is a type of hormonal agent which specifically modulates the effects of sex hormones and of their biological targets, the sex hormone receptors. The sex hormones include androgens such as testosterone, estrogens such as estradiol, and progestogens such as progesterone. Sex-hormonal agents may be either steroidal or nonsteroidal in chemical structure and may serve to either enhance, inhibit, or have mixed effects on the function of the sex hormone systems. Sex-hormonal agents are used in medicine for a variety of purposes including hormone therapy (e.g., menopausal hormone therapy, androgen replacement therapy, transgender hormone therapy), antihormone therapy (e.g., androgen deprivation therapy, estrogen deprivation therapy), and hormonal contraception, among others. Types and examples Androgen receptor (AR) modulators * Androgens and anabolic steroids (AR agonists) ** Examples: testosterone, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progesterone Receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene residing on chromosome 11q22, it has two isoforms, PR-A and PR-B, that differ in their molecular weight. The PR-B is the positive regulator of the effects of progesterone, while PR-A serve to antagonize the effects of PR-B. Mechanism Progesterone is necessary to induce activation of the progesterone receptors. When no binding hormone is present the carboxyl terminal inhibits transcription. Binding to a hormone induces a structural change that removes the inhibitory action. Progesterone antagonists prevent the structural reconfiguration. After progesterone binds to the receptor, restructuring with dimerization follows and the complex enters the nucleus and binds to DNA. There transcription takes place, resulting in formation of messenge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 major progestogen in the body. Progesterone has a variety of important functions in the body. It is also a crucial metabolic intermediate in the production of other endogenous steroids, including the sex hormones and the corticosteroids, and plays an important role in brain function as a neurosteroid. In addition to its role as a natural hormone, progesterone is also used as a medication, such as in combination with estrogen for contraception, to reduce the risk of Uterine cancer, uterine or cervical cancer, in hormone replacement therapy, and in feminizing hormone therapy. It was first prescribed in 1934. Biological activity Progesterone is the most important progestogen in the body. As a potent agonist of the progesterone receptor, nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Agonist
In pharmacology, partial agonists are drugs that bind to and activate a given Receptor (biochemistry), receptor, but have only partial Intrinsic activity, efficacy at the receptor relative to a full agonist. They may also be considered Ligand (biochemistry), ligands which display both agonistic and Receptor antagonist, antagonistic effects—when both a full agonist and partial agonist are present, the partial agonist actually acts as a competitive antagonist, competing with the full agonist for receptor occupancy and producing a net decrease in the receptor activation observed with the full agonist alone. Clinically, partial agonists can be used to activate receptors to give a desired submaximal response when inadequate amounts of the endogenous ligand are present, or they can reduce the overstimulation of receptors when excess amounts of the endogenous ligand are present. Some currently common drugs that have been classed as partial agonists at particular receptors include buspi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
