Selective estrogen receptor modulators (SERMs) is a class of medication that acts on the estrogen receptor. A characteristic that distinguishes these substances from receptor agonists and antagonists is that their action is different for various tissues, thereby granting the possibility to selectively inhibit or stimulate estrogen-like action in various tissues. A medication is a licenced drug taken to cure or reduce symptoms of an illness or medical condition. ... Estrogens (also oestrogens) are a group of steroid compounds that function as the primary female sex hormone. ... The estrogen receptor is a receptor for estradiol (the main endogenous estrogen); it is located intracellularly, in parallel with other steroid hormone receptors. ...

Members

Members are:

• clomifene
• raloxifene
• tamoxifen
• toremifene
• bazedoxifene
• lasofoxifene

Clomifene or clomifene citrate (old name clomiphene, sold as Clomid®, Serophene®, Milophene® and many others) is a selective estrogen receptor modulator (SERM), used mainly in female infertility due to anovulation (e. ... Raloxifene is an oral selective estrogen receptor modulator which is used in the prevention of osteoporosis in postmenopausal women. ... Tamoxifen:chemical structure Tamoxifen is an oral selective estrogen receptor modulator which is used in breast cancer treatment, and is currently the worlds largest selling breast cancer treatment. ... Toremifene is an oral selective estrogen receptor modulator (SERM) which helps oppose the actions of estrogen in the body. ... Bazedoxifene is a selective estrogen receptor modulator (SERM), developed by Wyeth Pharmaceuticals. ...

Uses

SERMs are used dependent on their pattern of action in various tissues:

• clomifene is used in anovulation
• raloxifene is used for osteoporosis and is being studied as a breast cancer preventative
• tamoxifen and toremifene are used for breast cancer

Some SERMs may be good replacements for hormone replacement therapy (HRT), which has recently been discredited, although the above agents still have an unacceptably high risk of thrombosis and other side-effects to allow for widespread use. Clomifene or clomifene citrate (old name clomiphene, sold as Clomid®, Serophene®, Milophene® and many others) is a selective estrogen receptor modulator (SERM), used mainly in female infertility due to anovulation (e. ... In medicine, anovulation is absence of ovulation when it would be normally expected (in a post-menarchal, premenopausal woman). ... Raloxifene is an oral selective estrogen receptor modulator which is used in the prevention of osteoporosis in postmenopausal women. ... Osteoporosis is a disease of bone in which bone mineral density (BMD) is reduced and bone microarchitecture is disrupted. ... Breast cancer is cancer of breast tissue. ... Tamoxifen:chemical structure Tamoxifen is an oral selective estrogen receptor modulator which is used in breast cancer treatment, and is currently the worlds largest selling breast cancer treatment. ... Breast cancer is cancer of breast tissue. ... Hormone replacement therapy (HRT) is a system of medical treatment for perimenopausal and postmenopausal women, based on the assumption that it may prevent discomfort and health problems caused by diminished circulating estrogen hormones. ... Thrombosis is the formation of a clot or thrombus inside a blood vessel, obstructing the flow of blood through the circulatory system. ...

Method of action

Although the SERMs have no immediate structural relationship with 17β-estradiol, they are stereochemically similar to this estrogen. Estradiol (17-beta estradiol) is a sex hormone. ... The different types of isomers. ...

There are three types of estrogen receptors, which are intracellular: α (α homodimer), β (β homodimer) and αβ (α- and β-receptor heterodimer). Different tissues have more or less of each class. In turn, each SERM has more affinity to one and less to the other estrogen receptor isoform. The α-receptor is generally stimulatory, but the β-receptor may inhibit the α-isoform as well as suppressing transcription independently. The estrogen receptor is a receptor for estradiol (the main endogenous estrogen); it is located intracellularly, in parallel with other steroid hormone receptors. ... In cell biology, molecular biology and related fields, the word intracellular means inside the cell. It is used in contrast to extracellular (outside the cell). ...

Genes activated or suppressed by estrogen receptors generally have an estrogen response element sequence in their promotor. This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ...

Some SERMs, through this process, also augment the transcription of coactivator molecules, which may be indispensable for their pharmacological action.

Actions

The actions of SERMs on various tissues:

• Pituitary gland - clomifene blocks estrogen action, leading to an increase of follicle-stimulating hormone.
• Uterus - tamoxifen may increase endometrial carcinoma risk, but raloxifene does not. Data on toremifene and clomifene is insufficient.
• Breast - all SERMs decrease breast cancer risk, and tamoxifen is mainly used for its ability to inhibit growth in estrogen receptor-positive breast cancer.
• Deep venous thrombosis - the risk may be elevated in all SERMs.
• Cholesterol and triglycerides - levels respond favorably to SERMs.
• Bone turnover and postmenopausal osteoporosis respond favorably to SERMs.
• Hot flashes are increased by all SERMs.

Located at the base of the skull, the pituitary gland is protected by a bony structure called the sella turcica. ... Follicle stimulating hormone Follicle stimulating hormone (FSH) is a hormone synthesised and secreted by gonadotropes in the anterior pituitary gland. ... Female internal reproductive anatomy The uterus or womb is the major female reproductive organ of most mammals, including humans. ... Endometrial cancer involves cancerous growth of the endometrium (lining of the uterus). ... The term breast, also known by the Latin mamma in anatomy, refers to the upper ventral region of an animals torso, particularly that of mammals, including human beings. ... It has been suggested that Deep Vein Thrombosis be merged into this article or section. ... Cholesterol chemical structure Cholesterol is a steroid, a lipid, and an alcohol, found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. ... Triglycerides (also known as triacylglycerols or triacylglycerides) are glycerides in which the glycerol is esterified with three fatty acids. ... Grays illustration of a human femur, a typically recognized bone. ... Osteoporosis is a disease of bone in which bone mineral density (BMD) is reduced and bone microarchitecture is disrupted. ...

References

• Riggs BL, Hartmann LC. Selective estrogen-receptor modulators - mechanisms of action and application to clinical practice. N Engl J Med 2003;348:618-29. PMID 12584371.

The New England Journal of Medicine (NEJM) is a peer-reviewed medical journal published by the Massachusetts Medical Society. ...

External links

• STAR: a head-to-head comparison of tamoxifen and raloxifene as breast-cancer preventatives