Objective: To evaluate premenstrual daily dosing with fluoxetine for treatment of premenstrual dysphoric disorder.
Methods: After a two-cycle screening and one-cycle single-blind placebo period, 260 women were randomized to fluoxetine 10 mg, fluoxetine 20 mg, or placebo (dosed daily from 14 days before next expected menses through the first full day of bleeding) for three cycles. Women recorded premenstrual dysphoric disorder symptoms daily using a computerized version of the Daily Record of Severity of Problems.
Results: Premenstrual daily fluoxetine 20 mg demonstrated significant improvement in mean Daily Record of Severity of Problems luteal scores compared with placebo (P =.005); premenstrual daily fluoxetine 10 mg did not (P =.100). Daily Record of Severity of Problems total scores were statistically significantly improved by the first treatment cycle for both active treatment groups. However, only fluoxetine 20 mg remained statistically significantly superior to placebo throughout the active treatment phase of the trial. Both fluoxetine groups showed significant treatment advantage over placebo for mood-related symptoms (P <.05). Only premenstrual daily fluoxetine 20 mg showed significant treatment advantage over placebo for physical symptoms of breast tenderness (P <.001), bloating (P =.001), and joint/muscle pain (P =.037). Treatment was well tolerated; discontinuations due to adverse events did not differ among the three groups (P =.316).
Conclusion: Premenstrual daily dosing with fluoxetine effectively treats mood, physical, and social functioning symptoms associated with premenstrual dysphoric disorder. Fluoxetine 20 mg appears to have comparable tolerability with, and better efficacy than, fluoxetine 10 mg.