Continuous, daily levonorgestrel/ethinyl estradiol vs. 21-day, cyclic levonorgestrel/ethinyl estradiol: efficacy, safety and bleeding in a randomized, open-label trial.

BACKGROUND: This Phase 3, randomized, open-label, multicenter study conducted at 44 sites in Europe evaluated the safety and efficacy of a continuous, daily regimen of levonorgestrel (LNG) 90 mcg/ethinyl estradiol (EE) 20 mcg compared with a 21-day, cyclic LNG 100 mcg/EE 20 mcg regimen.

STUDY DESIGN: Three hundred twenty-three healthy women were randomized to continuous LNG 90 mcg/EE 20 mcg and 318 subjects to cyclic LNG 100 mcg/EE 20 mcg for 1 year (13 pill packs). Pearl index, adverse event (AE) incidence and bleeding profiles were assessed.

RESULTS: No pregnancies occurred with the continuous oral contraceptive (OC) (Pearl index=0.00). As the study progressed, the percentage of women who achieved amenorrhea during each 28-day pill pack increased: 40% at pill pack 7, 53% at pill pack 13. The percentage of women with no bleeding [with or without spotting (defined as not requiring sanitary protection)] was 50%, 69% and 79% at pill packs 3, 7 and 13, respectively. The incidence of AEs was similar to that of the cyclic OC (except for metrorrhagia and vaginal bleeding in the first 6 months).

CONCLUSIONS: Continuous LNG 90 mcg/EE 20 mcg was shown to be a safe and effective OC in this direct comparison to a cyclic OC. Suppression of menses and the potential for no bleeding requiring sanitary protection may be provided by this continuous, low-dose OC.