Objective: To assess the efficacy of the combined oral contraceptive containing 3-mg drospirenone/20-microgram ethinyl estradiol (3-mg drospirenone/20-microgram ethinyl estradiol) administered as 24 consecutive days of active treatment after a 4-day hormone-free interval (24/4 regimen) compared with placebo for the treatment of moderate acne vulgaris.
Methods: Healthy females aged 14-45 years with moderate acne were randomized in this double-blind study to 3-mg drospirenone/20-microgram ethinyl estradiol (n=270) or placebo (n=268) for six cycles of 28 days. The primary outcome measures of acne lesion counts and Investigator Static Global Assessment scale ratings were assessed at baseline and during cycles 1, 3, and 6.
Results: The percentage reduction from baseline to endpoint for total lesions is 46.3% for 3-mg drospirenone/20-microgram ethinyl estradiol 24/4 combination oral contraceptive group and 30.6% for placebo group (P<.001). The likelihood of participants in the 3-mg drospirenone/20-microgram ethinyl estradiol 24/4 regimen group having "clear" or "almost clear" skin as rated by the investigators at endpoint was about threefold (odds ratio 3.13, 95% confidence interval 1.69-5.81; P=.001) greater than in the placebo group. The 3-mg drospirenone/20-microgram ethinyl estradiol 24/4 regimen was well tolerated.
Conclusion: The low-dose combined oral contraceptive containing 3-mg drospirenone/20-microgram ethinyl estradiol administered in a 24/4 regimen significantly reduced acne lesion counts more effectively than placebo and demonstrated greater improvement in the Investigator Static Global Assessment rating of acne. The safety profile was consistent with low-dose combined oral contraceptive use.
Trial registration: ClinicalTrials.gov NCT00651469.