Objective: To compare the efficacy of a new low-dose oral contraceptive pill (OCP) formulation with placebo in reducing symptoms of premenstrual dysphoric disorder.
Methods: This multicenter, double-blind, randomized clinical trial consisted of 2 run-in and 3 treatment cycles with daily symptom charting; 450 women with symptoms of premenstrual dysphoric disorder were randomized to either placebo or an OCP formulation containing drospirenone 3 mg and ethinyl estradiol 20 microg. Hormones were administered for 24 days, followed by 4 days of inactive pills (24/4).
Results: Scores on the total Daily Record of Severity of Problems decreased by -37.49 in the drospirenone/ethinyl estradiol group and by -29.99 in the placebo group (adjusted mean difference -7.5, 95% confidence interval [CI] -11.2 to -3.8; P < .001 by rank analysis of covariance). Mood symptom scores were reduced by -19.2 and -15.3 in active-treatment and placebo groups, respectively (adjusted mean difference -3.9, 95% CI -5.84 to -2.01; P = .003); physical symptom scores were reduced by -10.7 and -8.6 in active-treatment and placebo groups, respectively (adjusted mean difference -2.1, 95% CI -3.3 to -0.95; P < .001); and behavioral symptom scores were reduced by -7.7 and -6.2 in active-treatment and placebo groups, respectively (adjusted mean difference -1.5, 95% CI -2.251 to -0.727; P < .001). Response, defined as a 50% decrease in daily symptom scores, occurred in 48% of the active-treatment group and 36% of the placebo group (relative risk 1.7, 95% CI 1.1 to 2.6; P = .015) and corresponds to a number-needed-to-treat of 8 patients.
Conclusion: A 24/4 regimen of drospirenone 3 mg and ethinyl estradiol 20 mug improves symptoms associated with premenstrual dysphoric disorder.
Level of evidence: I.