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Antiprogestogens
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 receptor antagonist, blocking the progesterone receptor (PR) and/or steroidogenesis inhibitor, inhibiting or antigonadotropin, suppressing progestogen biosynthesis, production. Antiprogestogens are one of three types of sex-hormonal agent, sex hormone antagonists, alongside antiestrogens and antiandrogens. Clinical applications Antiprogestogens are used as abortifacients, emergency contraception, 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 mifepristone, the selective progesterone receptor modulator (SPRM) ulipristal acetate, and the ... [...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] |
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] |
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] |
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] |
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] |
Antiestrogen
Antiestrogens, also known as estrogen antagonists or estrogen blockers, are a class of drugs which prevent estrogens like estradiol from mediating their biological effects in the body. They act by blocking the estrogen receptor (ER) and/or inhibiting or suppressing estrogen production., Antiestrogens are one of three types of sex hormone antagonists, the others being antiandrogens and antiprogestogens. Antiestrogens are commonly used to stop steroid hormones, estrogen, from binding to the estrogen receptors leading to the decrease of estrogen levels. Decreased levels of estrogen can lead to complications in sexual development. Types and examples Antiestrogens include selective estrogen receptor modulators (SERMs) like tamoxifen, clomifene, and raloxifene, the ER silent antagonist and selective estrogen receptor degrader (SERD) fulvestrant, aromatase inhibitors (AIs) like anastrozole, and antigonadotropins including androgens/anabolic steroids, progestogens, and GnRH an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemeprost
Gemeprost (16, 16-dimethyl-trans-delta2 PGE1 methyl ester) is an analogue of prostaglandin E1. Clinical use It is used as a treatment for obstetric bleeding. It is used with mifepristone to terminate pregnancy up to 24 weeks gestation. Side effects Vaginal bleeding, cramps, nausea, vomiting, loose stools or diarrhea, headache, muscle weakness; dizziness; flushing; chills; backache; dyspnoea; chest pain; palpitations and mild pyrexia. Rare: Uterine rupture, severe hypotension, coronary spasms with subsequent myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom ...s. References External links * {{Portal bar , Medicine Abortifacients Prostaglandins Sanofi Uterotonics Medication abortion Methyl esters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostaglandin
Prostaglandins (PG) are a group of physiology, physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have been found in almost every Tissue (biology), tissue in humans and other animals. They are derived enzymatically from the fatty acid arachidonic acid. Every prostaglandin contains 20 carbon atoms, including a carbon ring, 5-carbon ring. They are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives. The structural differences between prostaglandins account for their different biological activities. A given prostaglandin may have different and even opposite effects in different tissues in some cases. The ability of the same prostaglandin to stimulate a reaction in one tissue and inhibit the same reaction in another tissue is determined by the type of receptor (biochemistry), receptor to which the prostaglandin binds. They act as autocrine or paracrine factors with their target cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silent Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves ." '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include s, |
Selective Progesterone Receptor Modulator
A selective progesterone receptor modulator (SPRM) is an agent that acts on the progesterone receptor (PR), the biological target of progestogens like progesterone. A characteristic that distinguishes such substances from full receptor agonists (e.g., progesterone, progestins) and full antagonists (e.g., aglepristone) is that their action differs in different tissues, i.e. agonist in some tissues while antagonist in others. This mixed profile of action leads to stimulation or inhibition in tissue-specific manner, which further raises the possibility of dissociating undesirable adverse effects from the development of synthetic PR-modulator drug candidates. History Ever since the discovery of the progesterone hormone in the mid-1930s. and especially after the discovery of its receptor in 1970 there has been a significant interest in developing an antagonistic agent for therapeutic use. Various progesterone analogs, known as progestins, were synthesized and in 1981 the first p ... [...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] |
