Safety Study of Ethinylestradiol/Drospirenone in Dysmenorrhea

1 tablet per day Drospirenone (DRSP) 3 mg/Ethinylestradiol (EE) 20 µg for 24 days and 1 tablet per day placebo for 4 days in each 28-day cycle; treatment duration 52 weeks (13 cycles)

1 tablet per day Drospirenone 3 mg/Ethinylestradiol 30 µg for 24 days and 1 tablet per day placebo for 4 days in each 28-day cycle; treatment duration 24 weeks (6 cycles)