Cycle control with desogestrel-containing oral contraceptives - Comparison of a monophasic and triphasic regimen

Objective - To examine the effect of mono- and triphasic desogestrel- containing oral contraceptives on cycle control. Setting - Multicenter, international (U.S. and Canada). Patients and Interventions - About 4,000 women, aged 18-35, healthy, neither pregnant nor lactating, were followed for almost 37,700 cycles of use of a monophasic 150 μg desogestrel/30 μg ethinyl estradiol OC or Sunday- or day-1 start regimens of a triphasic preparation containing 50/100/150 μg desogestrel/35/30/30 μg ethinyl estradiol administered on a 7/7/7 schedule. Standard diary methods were used to collect data on breakthrough bleeding, spotting, and absence of withdrawal bleeding. Results - The two formulations demonstrated very low and, in fact, remarkably similar rates of breakthrough bleeding, spotting, and absence of withdrawal bleeding. A statistical analysis of these characteristics of the total study populations, per cycle, revealed no statistically significant differences between the formulations. Conclusion - Although the triphasic formulation contains the lowest estrogen dose of any triphasic available, 33% less progestin than the monophasic formulation, it maintains comparable cycle control.