Antiestrogens clomiphene

Therapeutically, gonadotropins are used to induce ovulation in infertile women. The antiestrogens clomiphene (5.37) and tamoxifen (5.38) are also used for this purpose since they counteract the ovulation-inhihitory effect of estrogens. Pregnancy tests depend on the presence of an increased hCG concentration in the urine after fertilization. 

ANTIESTROGENS CLOMIPHENE AND FULVESTRANT These compounds are pure antagonists in aU tissues. Clomiphene (CLOMID, SEROPHENE, others) is approved for the treatment of infertility in anovulatory womsrr, fulvestrant (FASLODEX, ICI 182,780) is used to treat breast cancer in women with disease progression after tamoxifen. 

For the purposes of this article, antiestrogens are compounds that counteract the biological activity of estrogens at the receptor level. In the late 1970s, there were no steroidal antiestrogens in widespread clinical use. Clomiphene [911 -45-5]( ) and tamoxifen/7(954(9-25 -/7(9) were nonsteroidal antiestrogens that had been employed for the treatment of female infertility and breast cancer, respectively. 

Some tumors are estrogen-dependent and the use of an antiestrogen has therapeutic value. One such antineoplastic agent appears to be patterned after clomiphene. Complex aryl ketone 204 is treated with phenyl magnesium chloride and the resulting tertiary... 

Ben-Baruch G, Schreiber G, Sokolovsky M (1982) Cooperativity pattern in the interaction of the antiestrogen drug clomiphene with the muscarinic receptors. Mol Pharmacol 21 287-293... 

In another study, the adverse effects of the antiestrogenic effects of clomiphene citrate were hot flushes (10%), mood swings, depression, headaches (1%), pelvic pain (5.5%), nausea (2%), breast tenderness (2-5%), dryness and loss of hair (0.3%), visual symptoms, halos and streaks around lights (particularly at night), blurring, and scotoma (1.5%) (3). 

In one case, a complex cyst, thought to be due to ovarian hyperstimulation, resolved after monthly administration of a depot gonadorelin (GnRH) receptor agonist without abandoning tamoxifen (72). One might expect some patients to react to tamoxifen with ovarian hyperstimulation, since another non-steroidal antiestrogen (that is clomiphene) is used for ovarian stimulation and also on occasion produces cysts. 

Premature ovarian failure can be induced in offspring exposed in utero by active metabolites such as 6-mercaptopurine. Tamoxifen (treatments for breast cancer) and clomiphene (to induce ovulation) are antiestrogens that can inhibit uterine decidual induction in pseudopregnant rats. 

Correct answer = A. Norgestrel and norethindrone are progestins, and clomiphene is an antiestrogen. Estradiol is largely inactivated by... 

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