A phase 3, randomized, open-label, multicenter study was conducted at 44 sites in Europe to evaluate 2 different doses of Wyeth's oral levonorgestrel (LNG) and ethinyl estradiol (EE) over 1 year: continuous daily, noncyclic LNG 90 μg/EE 20 μg and 21-day cyclic LNG 100 μg/EE 20 μg. The study involved ~641 women who took either version of the oral contraceptive in the form of 13 pill packs over the course of 12 months. The study authors noted that a majority of women taking the continuous daily LNG/EE combination reported amenorrhea: 27.1% at pill pack 3, 39.6% at pill pack 7, and 52.9% at pill pack 13. The researchers also noted an increase in the percentage of participants who experienced no bleeding with subsequent pill packs: 50%, 69%, and 79% at packs 3, 7, and 13, respectively. The researchers concluded that these results showed that the noncyclic regimen has a similar safety profile, compared with the established 21- day regimen. The study results were presented at the Annual Meeting of the American College of Obstetricians and Gynecologists on May 8, 2006.
Ms. Farley is a freelance medical writer based in Wakefield, RI.