Endometriosis progestins

The progestins are used in the treatment of amenorrhea, endometriosis, and functional uterine bleeding. Progestins are also used as oral contraceptives, either alone or in combination with an estrogen (see the Summary Drug Table Female Hormones and Table 52-1). 

Progestins are nsed for varions menstmal cycle disorders, for functional uterine bleeding of various origins, and as a contraceptive. Progestin therapy is also used to treat endometriosis and endometrial carcinomas. Progesterone is not effective when taken orally due to intensive metabolism, and therefore it is used by either parenteral or transvaginal introduction. 

Other clinical uses of estrogens and progestins include the treatment of dysfunctional uterine bleeding, dysmenorrhea, endometriosis, and rarely, metastatic prostate cancer. 

Endometriosis Endometriosis, which was formerly treated by surgical removal of the ovaries and uterus, is now treated with the continuous administration of progestin, or with progestin combined with estrogen. In addition, progestin may be useful in the management of endometrial carcinoma. 

All medical therapies (nonsteroidal anti-inflammatory drugs, oral contraceptives, progestins, danazol, or gonadotropinreleasing hormone agonists) are equally efficacious in treating endometriosis-related pain based on available evidence. Choice among agents is determined primarily by side-effect profile, cost, and individual patient response. 

Clinical use A major therapeutic use of the progestins is as a component of oral or implantable contraceptives. They are used in HRT to prevent estrogen-induced endometrial cancer. Large doses of medroxyprogesterone can be used to produce anovulation and amenorrhea in women with dysmenorrhea, endometriosis, or bleeding disorders. 

Danazol Danazol is a weak partial agonist that binds to progestin, androgen, and glucocorticoid receptors in cells and to steroid transport proteins in the blood. Danazol also inhibits several P450 enzymes involved in gonadal steroid synthesis. The drug is sometimes used in the treatment of endometriosis and fibrocystic disease of the breast. 

Medroxyprogesterone acetate (Fig. 46.13), administered by injection (Depo-Provera), orally, or delivered via lUD, effectively suppresses the HPO axis, induces anovulation, and reduces serum estrogen levels (83). This prevents menstruation and endometrial implant growth. As a result, endometriosis-related pain is minimized in approximately 90% of the patients. Drug therapy selection should reflect the fact that pharmacological therapy is likely to be required on a chronic basis. The progestins are fairly well tolerated and relatively inexpensive, but they are not without adverse effects. 

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