Aspirin for treatment of lithium-associated sexual dysfunction in men: Randomized double-blind placebo-controlled study

Objectives: The aim of the present study was to assess the effect of aspirin on lithium-related sexual dysfunction in men with stable bipolar affective disorder (BAD). Methods: In a randomized, double-blind, placebo-controlled study, 32 men with stable BAD who had been on lithium maintenance therapy randomly received aspirin (240 mg/day) or placebo for six weeks. The International Index for Erectile Function (IIEF) was used to assess sexual symptoms at baseline, Week 3, and Week 6. Depressive and mania symptoms and plasma lithium concentrations were assessed at baseline and Week 6. Side effects were assessed using a checklist. Results: Thirty patients (15/group) completed the study. Baseline and endpoint lithium concentrations and mania and depressive symptoms did not differ significantly between the two groups. Significant effects of time × treatment interaction were observed for total score [Greenhouse-Geisser: F(1.410,39.466) = 6.084, p = 0.010] and erectile function [Greenhouse-Geisser: F(1.629,45.602) = 7.250, p = 0.003]. By Week 6, patients in the aspirin group showed significantly greater improvement in the total (63.9% improvement from the baseline) and erectile function domain (85.4% improvement from the baseline) scores than the placebo group (14.4% and 19.7% improvement from the baseline, p-values = 0.002 and 0.001, respectively). By Week 6, 12 (80%) patients in the aspirin group and three (20%) patients in the placebo group met the criteria of minimal clinically important change [χ²(1) = 10.800, p = 0.001]. Other IIEF domains also showed significant improvement at the end of the trial. The frequency of side effects was similar between the two groups. Conclusion: Aspirin effectively improves lithium-related sexual dysfunction in men with stable BAD.