| pubmed-article:3659794 | pubmed:otherAbstract | PIP: Synthetic progestins derived from nortestosterone provide a promising contraceptive alternative for women with contraindications for estrogens. Progesterone and synthetic progestins reduce vasodilatation and edema induced by estrogens and stop estrogen-dependent cellular multiplication in target tissue. Progestins have 2 kinds of contraceptive affect: antigonadotropic action at sufficient doses, and peripheral action at lower doses. The cervical mucus is modified in composition and volume, becoming hostile to sperm; the endometrial mucus atrophies; and tubal motility is slowed. High dose progestins are administered from the 5th or 10th to the 25th cycle day, with the earlier date preferred for women with shorter cycles. They are an ideal method for women with endometrial hyperplasia or benign breast disease or histories of breast or uterine cancer, as well as for women over 40 with dysovulatory cycles. Contraindications to high dose progestins include obesity, hypertension, lipid metabolic anomalies, and diabetes. Low dose progestin-only pills are administered at the exact same time each day including during menstruation. They are attractive for some women because they contain no estrogen, a reduced progestin dose causing fewer headaches and less somnolence, and fewer metabolic effects. Low dose progestins are indicated for lactating women, those with contraindications to estrogens such as obesity, hypertension, hyperlipidemia, and diabetes, and those with renal or cardiac insufficiency with valvulopathy. Low dose progestins are also indicated for nulliparas and other women for whom IUDS are contraindicated. Women using low dose progestins should never take drugs that act as enzymatic inductors, which speed hepatic degradation of steroids and reduce their efficiency. A resulting pregnancy is likely to be extrauterine because of slowed tubal transport. The failure rate of low dose progestins ranges from .9-3%, with higher failure rates among younger women. About 30% of users initially experience spotting, which despite its usual disappearance after 2-3 months of use is the most common reason for discontinuing the method. Low dose progestins have no metabolic or vascular effects, but they may cause a relative hyperestrogenism is some users. Other modes of administration of progestin contraception include continuous high doses, never justified solely for contraception. Trimonthly injections of medroxyprogesterone acetate of norethindrone enanthate provide contraception through a long lasting antigonadotropic effect. Metrorrhagia and amenorrhea are among possible side effects. The method is used primarily in developing countries where its ease of use is a major advantage. Subcutaneous implants releasing continuous doses of levonorgestrel provide contraceptive protection for over 5 years. The cumulative failure rate is 1.7 at 5 years. Metabolic tolerance is good. The major side effect is menstrual irregularity. | lld:pubmed |
