Progestogens in gynaecological practice

Gynecologists use either oral or parenteral progestogens either alone or in combination with estrogens to treat various conditions. Parenteral routes of progestogen delivery are intramuscular injections, intravaginal pessaries, subcutaneous implants, and vaginal rings. Progestogens treat dysfunctional uterine bleeding by first controlling the acute bleeding episode and then by establishing normal ovulatory cycles. 1-2 tablets of medroxyprogesterone acetate (MPA)/day or 1-3 tablets of norethindrone/day should stop uterine bleeding in 72 hours. If not, 25 mg intravenous premarin should control it in 6-24 hours. Cyclical progestational (e.g., MPA) therapy for 3-6 cycles should establish normal ovulatory cycles. After appropriate laparoscopic staging by double puncture technique, progestogens can be used to treat mild-moderate endometriosis. Gynecologists should consider the following criteria when selecting the ideal progestin for hormone replacement therapy: adjustment of dosage of progestin and estrogen over 3-6 months to maintain the beneficial effects of the estrogen and to minimize the adverse effects of the progestin, progestin dosage sufficient to protect against endometrial hyperplasia and cancer, economical progestin, and minimization of weight gain, depression, oral intolerance, and androgenic action. Hydrogesterone and MPA meet these criteria. Oral contraceptives with a progestin and the smallest possible dose of estrogen are well-tolerated, cause no break-through bleeding, produce minimal side effects, and protect against pregnancy (99% contraceptive effectiveness rate). They also protect against endometrial cancer, endometriosis, premenstrual tension, dysmenorrhea, and irregular cycles. Intramuscular injections of progestins (MPA, NET-EN), subcutaneous levonorgestrel implant, and the levonorgestrel IUD are new contraceptive developments and provide a high degree of contraceptive efficacy. MPA at very high doses cause remission of breast endometrial lesions.