A Double-Blind, Randomized, Placebo-Controlled Trial of Paroxetine Controlled-Release in Irritable Bowel Syndrome

Background: Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disease that causes significant impairment in quality of life and accounts for $8 billion per year to the healthcare system and loss of productivity in the workplace. Objective: The authors examined the efficacy and safety of paroxetine controlled-release (paroxetine-CR) in patients with IBS. Method: Seventy-two patients with IBS participated in a 12-week, double-blind, randomized, placebo-controlled study of paroxetine-CR (12.5 mg-50 mg/day). Efficacy was measured by Composite Pain Scores (primary outcome) and the Clinical Global Impression-Improvement (CGI-I) and Severity (CGI-S) ratings. Results: In intent-to-treat analyses, there were no significant differences between paroxetine-CR (N = 36) and placebo (N = 36) on reduction in Composite Pain Scores, although the proportion of responders on CGI-I was significantly higher in the paroxetine-CR group. The treatment was well tolerated. Conclusion: The study did not demonstrate a statistically significant benefit for paroxetine-CR over placebo on the primary outcome measure, although there was improvement in secondary outcome measures. Overall, paroxetine-CR seems to have potential benefit in IBS. Studies with adequate samples may clarify the role of paroxetine-CR in IBS.