A new low-dose oral contraceptive pill reduces symptoms of premenstrual syndrome (PMS), including a severe form called premenstrual dysphoric disorder. Oral contraceptives are commonly used for premenstrual conditions, usually milder syndromes, but researchers from the Yale University School of Medicine found that the empirical evidence supporting their use has been lacking. They conducted a study, comparing an oral contraceptive with a placebo for premenstrual syndrome, including premenstrual dysphoric disorder. The oral contraceptive agent contained a low dose of ethinyl oestradiol (20 micrograms) and a newer progestin, drospirenone. To investigate its effects, researchers randomly assigned 450 women with symptoms of premenstrual syndrome to receive the oral contraceptive or placebo. The active formulation was administered for 24 days followed by 4 days of inactive pills. The response, defined as a 50 percent decrease in daily symptom scores, occurred in 48 percent of the active-treatment group and 36 percent of the placebo group. The new dosing schedule of 24 days of active treatment followed by 4 days of blanks, rather than the usual 21 days of active treatment and 7 days of blanks, could also have contributed to the therapeutic benefits.
Obstetrics and Gynecology,
September 2005