Good news about Lybrel, Wyeth's new continuous, low-dose (20 mcg ethinyl estradiol/90 mcg levonorgestrel) birth control pill. Lybrel, designed to be taken daily with no hormone-free intervals, showed complete ovulation suppression in a small study, and significant control of premenstrual symptoms in a larger, but not placebo controlled, study:
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.
The second study found that the same COC regimen significantly alleviated premenstrual symptoms.
A total of 278 women with a history of cycle-related symptoms or dysmenorrhea were monitored during three cycles of the COC regimen, with no pill-free interval. The subjects maintained a daily diary, rating mood, behavior, pain, and physical symptoms using the Penn Daily Symptom Rating scale. Two-thirds of the women improved their scores by 50% in the first 28-day cycle (one pill pack). In addition, work productivity improved.
"What impressed me the most was the very immediate response of the first cycle and the strong response at end point," said lead investigator Ellen Freeman, Ph.D., of the University of Pennsylvania in Philadelphia. "Almost all the response occurred right away. That's fast. Secondly, I was surprised that all four of the symptom subscales seemed to respond similarly."
More from Wyeth here.
ETA: It appears the brand name in Canada and the EU will be Anya.