 |
|
|
Letrozole
|
|
| Systematic (IUPAC) name | |
| 4-[(4-cyanophenyl)-(1,2,4-triazol-1-yl)methyl]benzonitrile | |
| Identifiers | |
| CAS number | |
| ATC code | L02 |
| PubChem | |
| DrugBank | |
| Chemical data | |
| Formula | C17H11N5 |
| Mol. mass | 285. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The Anatomical Therapeutic Chemical Classification System is used for the classification of drugs It is controlled by the WHO Collaborating Centre for Drug A section of the Anatomical Therapeutic Chemical Classification System. PubChem is a Database of chemical Molecules The system is maintained by the National Center for Biotechnology Information (NCBI a component The DrugBank database available at the University of Alberta is a unique Bioinformatics and Cheminformatics resource that combines detailed drug (i A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 The molecular mass (abbreviated m of a substance, more commonly referred to as molecular weight and abbreviated as MW, is the Mass of one 303 g/mol |
| SMILES | & |
| Pharmacokinetic data | |
| Bioavailability | 99. In Pharmacology, bioavailability is used to describe the fraction of an administered Dose of unchanged drug that reaches the Systemic circulation, one of 9% |
| Protein binding | 60%, mainly to albumin |
| Metabolism | ? |
| Half life | 2 days |
| Excretion | ? |
| Therapeutic considerations | |
| Pregnancy cat. |
? |
| Legal status |
?(CA) |
| Routes | ? |
Letrozole (INN, trade name Femara) is an oral non-steroidal aromatase inhibitor that has been introduced for the adjuvant treatment of hormonally-responsive breast cancer. A drug's efficiency may be affected by the degree to which it binds to the proteins within Blood plasma. Drug metabolism is the Metabolism of drugs, their Biochemical modification or degradation usually through specialized enzymatic systems The biological half-life of a substance is the time it takes for a substance (drug radioactive nuclide or other to lose half of its pharmacologic physiologic or radiologic activity Excretion is the process of eliminating waste products of Metabolism and other non-useful materials The pregnancy category of a pharmaceutical agent is an assessment of the risk of fetal injury due to the pharmaceutical if it is used as directed by the mother during The regulation of therapeutic goods, that is drugs and therapeutic devices, varies by jurisdiction Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page In Pharmacology and Toxicology, a route An International Nonproprietary Name ( INN; also known as rINN, for recommended International Nonproprietary Name or pINN for proposed Aromatase inhibitors ( AI) are a class of drugs used in the treatment of Breast cancer and Ovarian cancer in postmenopausal women that Breast cancer is a Cancer that starts in the cells of the Breast in women and men
Estrogens are produced by the conversion of androgens through the activity of the aromatase enzyme. Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle, Androgen is the generic term for any natural or synthetic compound usually a Steroid Hormone, that stimulates or controls the development and maintenance of masculine Letrozole blocks production of estrogens in this way by competitive, reversible binding to the heme of its cytochrome P450 unit. Cytochrome P450 (abbreviated CYP, P450, infrequently CYP450) is a very large and diverse superfamily of Hemoproteins found in all Domains The action is specific, and letrozole does not reduce production of mineralo- or corticosteroids. In contrast, the antiestrogenic action of tamoxifen, the major medical therapy prior to the arrival of aromatase inhibitors, is due to its interfering with the estrogen receptor, rather than inhibiting estrogen production. Tamoxifen is an orally active Selective estrogen receptor modulator (SERM that is used in the treatment of Breast cancer and is currently the world's largest
Contents |
FDA-approved use
Letrozole is approved by the United States Food and Drug Administration (FDA) for the treatment of local or metastatic breast cancer that is hormone receptor positive or has an unknown receptor status in postmenopausal women. The United States of America —commonly referred to as the Side effects include signs and symptoms of hypoestrogenism. Hypoestrogenism refers to a lower than normal level of Estrogen. There is concern that long term use may lead to osteoporosis, which is why prescriptions of Letrozole are often accompanied by prescriptions of osteoporosis-fighting medication such as Fosamax. Osteoporosis is a Disease of Bone that leads to an increased risk of fracture.
Off-label use
It has been used for ovulation induction by fertility doctors since 2001; having less side-effects than clomiphene citrate (Clomid) for the patient. Clomifene ( INN) or clomiphene ( USAN and former BAN) or Clomid or Clomifert is a Selective estrogen receptor modulator (SERM A Canadian study presented at the American Society of Reproductive Medicine 2005 Conference suggests that it may increase the risk of birth defects compared with a control group, however a more detailed follow-up study found no basis for concern when letrozole is used for ovulation induction. The American Society for Reproductive Medicine (ASRM is an organization that wants to advance the "art science and practice of Reproductive medicine ". [1]
The manufacturer, Novartis, has issued letters to doctors in Canada and the United States reiterating that it is not approved for such a use and is not safe to use with pregnant women or women who may become pregnant. Novartis International AG is a multinational Pharmaceutical company based in Basel Switzerland that manufactures drugs such as Clozapine
Letrozole has shown to reduce estrogen levels by 98 percent while raising testosterone levels. Testosterone is a Steroid hormone from the Androgen group In mammals testosterone is primarily secreted in the testes of males and the Ovaries The anti-estrogen action of letrozole is preferred by athletes and bodybuilders for use during a steroid cycle to reduce bloating due to excess water retention and prevent the formation of gynecomastia related breast tissue that is a side effect of some anabolic steroids. A sportsperson ( British and American English) or athlete (principally American English is any person who participates regularly in a Sport. Bodybuilding is the process of maximizing Muscle hypertrophy. A steroid cycle is the period in time where an individual is actively taking Anabolic steroids. Gynecomastia, or gynaecomastia, ˌgaɪnəkoʊˈmæstiə is the development of abnormally large Mammary glands in Males resulting in breast enlargement which Anabolic steroids, or anabolic-androgenic steroids ( AAS) are a class of Steroid hormones related to the hormone Testosterone. Above 5mg/day for extended periods may cause kidney problems.
Letrozole has also been shown to delay the fusing of the growth plates in adolescents. The epiphyseal plate (or epiphysial plate, physis, or growth plate) is a hyaline Cartilage plate in the metaphyses of children and This may boost the effectiveness of growth hormone, and thus Letrozole is used to treat adolescents and children with short stature.
A related agent is anastrozole. Anastrozole ( INN, trade name Arimidex) is a drug indicated in the treatment of Breast cancer in post- menopausal women
Letrozole has also been used to treat endometriosis. Endometriosis (from endo, "inside" and metra, " Womb " is a common medical condition characterized by growth beyond or outside the uterus [2]
References
- ^ Tulandi T, Martin J, Al-Fadhli R, Kabli N, Forman R, Hitkari J, Librach C, Greenblatt E, Casper RF. Congenital malformations among 911 newborns conceived after infertility treatment with letrozole or clomiphene citrate. Fertil Steril. 2006 Apr 28. PMID 16650422
- ^ Endometriosis ESHRE abstract
See also
External links
Aromatase inhibitors ( AI) are a class of drugs used in the treatment of Breast cancer and Ovarian cancer in postmenopausal women thatDapyx Software network: MP3 Explorer | Ebook Manager | Zenithic