Once-Monthly Vaginal Contraceptive
In Early Clinical Trials
Intravaginal administration of progestogen for contraception is showing promise in early clinical trial, Daniel R. Mishell, Jr., MD, reported at the annual meeting of the American Fertility Society in Miami Beach.Silastic rings impregnated with medroxyprogesterone acetate are inserted into the vagina, in the same manner as a diaphragm, once a month. After removal to allow withdrawal bleeding, another ring is inserted. Slow release of the drug at a constant rate appears to inhibit ovulation.Dr. Mishell, who is associate professor of obstetrics and gynecology at the University of California School of Medicine, Los Angeles, and chief of obstetrics and gynecology at Harbor General Hospital, Torrance, has conducted four different studies using various ring designs. Drug levels ranged from 50 mg to 2 gm. Two of these studies are still underway.In the first study, a thick ring containing 2 gm