Low-dose COC effective in studies.(News)

Two studies demonstrated a positive response to an investigational low-dose continuous oral contraceptive in terms of suppression of ovulation and premenstrual symptoms and return to normal ovulation, researchers reported at the joint annual meeting of the American Society for Reproductive Medicine and the Canadian Fertility and Andrology Society.

Both studies were sponsored by Wyeth, which has submitted the contraceptive for approval by the Food and Drug Administration. If approved, the contraceptive would be marketed under the trade name Lybrel.

The oral formulation of 20-mcg ethinyl estradiol and 90-mcg levonorgestrel is designed to be taken daily with no hormone-free intervals.

One study, involving 37 women aged 18-35 years, showed complete inhibition of ovulation in all women while on the oral formulation.

"We showed that none of the subjects developed follicles equal to or greater than 10 mm during treatment," said investigator Susan A. Ballagh, M.D., of the Contraceptive Research and Development program, Arlington, Va., of the Eastern Virginia Medical School, Norfolk.

Participants followed the continuous oral contraception (COC) regimen for 84 days, using three pill-pack segments.

After discontinuation of contraception, the time to return to normal ovulation--defined as serum progesterone levels greater than 5 ng/mL--was a mean of 20 days. A total of 95% of subjects ovulated within 25 days after discontinuation.