Evaluation of a low-dose oral contraceptive pill for primary dysmenorrhea: a placebo-controlled, double-blind, randomized trial

ObjectiveTo evaluate the efficacy and safety of low-dose oral contraceptives (IKH-01; 0.035 mg ethinyl estradiol and 1 mg norethisterone) for patients with primary dysmenorrhea.DesignPlacebo-controlled, double-blind, randomized trial.SettingClinical trial sites in Japan.Patient(s)One hundred fifteen patients with primary dysmenorrhea.Intervention(s)Patients randomly assigned to receive IKH-01 or placebo for four cycles.Main Outcome Measure(s)Total dysmenorrhea score, verbal rating scale defining pain according to limited ability to work and need for analgesics, and visual analog scale (VAS).Result(s)Reduction in total dysmenorrhea score and VAS before and after treatment was significantly higher in the IKH-01 group than in the placebo group. Total dysmenorrhea score and VAS in the IKH-01 group significantly decreased from cycles 2 to 5. Overall incidence of adverse events was significantly higher in the IKH-01 group. Incidence decreased over time in the IKH-01 group; it was invariable in the placebo group. No serious adverse events occurred.Conclusion(s)IKH-01 could be used as a single agent or in combination with analgesics for treatment of primary dysmenorrhea.