Background: Better characterization of safety and efficacy of multiple doses of selective serotonin reuptake inhibitors for the treatment of a wider range of symptoms of premenstrual dysphoric disorder (PMDD) will provide clinicians with flexibility to provide symptom relief along with acceptable tolerability. This study was designed to assess the efficacy and tolerability of multiple doses of paroxetine controlled release (CR) in PMDD.
Methods: In a multicenter (43 outpatient U.S. sites), placebo-controlled trial, 327 females aged 18 to 45 years, with regular menstrual cycles, meeting DSM-IV criteria for PMDD, were randomly assigned to receive paroxetine CR 12.5 mg; paroxetine CR 25 mg; or placebo, once daily, for up to three treatment cycles. The primary efficacy outcome was change from baseline to end point in mean luteal phase Visual Analogue Scale-Mood (irritability, tension, affective lability, depressed mood) score.
Results: At end point, subjects treated with paroxetine CR (12.5 mg and 25 mg) demonstrated significant improvement in VAS-Mood scores compared with those who received placebo (paroxetine CR 12.5 mg mean treatment difference vs. placebo, -8.7 mm; 95% CI, -15.7, -1.7; p =.015; paroxetine CR 25 mg mean treatment difference vs. placebo, -12.1 mm; 95% CI, -18.9, -5.3; p <.001). Results were also significant across measures of physical symptoms and social functioning. Paroxetine CR was well tolerated; 9.5% of subjects treated with 12.5 mg and 13.5% of subjects treated with 25 mg withdrew from the trial due to adverse events, compared with 6.5% of subjects in the placebo group.
Conclusions: Both doses of paroxetine CR 12.5 mg and 25 mg daily are effective and well tolerated in patients who suffer from PMDD. Efficacy with both doses affords greater flexibility to the prescribing physician.