A naturalistic study of paroxetine in premenstrual syndrome: efficacy and side-effects during ten cycles of treatment.

Eighteen women with severe premenstrual syndrome (PMS) (premenstrual dysphoric disorder, PMDD) were treated openly with paroxetine for 10 consecutive menstrual cycles. Dosage was flexible (5-30 mg/day); also, the patients were free to chose between continuous medication and medication in the luteal phase only. The rating of premenstrual irritability, depressed mood, increase in appetite, and anxiety/tension was markedly lower during treatment with paroxetine than before, and this reduction in symptomatology appeared unabated for the entire treatment period. Sedation, dry mouth, and nausea were common side-effects but declined during the course of the trial; in contrast, reduced libido and anorgasmia, which were reported by almost 50% of the participants, were not improved with time. The results indicate that the beneficial effects as well as the sexual side-effects of serotonin reuptake inhibitors persist unchanged for at least 10 consecutive cycles of treatment.