Effect of the Antidepressant Venlafaxine in Functional Dyspepsia: A Randomized, Double-Blind, Placebo-Controlled Trial

Background & Aims: Antidepressants could be effective in the treatment of functional gastrointestinal disorders through their anticholinergic and pain-modulating effects. Previous studies with these drugs lacked sufficient power and were predominantly conducted in patients with irritable bowel syndrome. This study aimed to assess the effectiveness of the serotonin and norepinephrine reuptake inhibitor venlafaxine in patients with functional dyspepsia. Methods: This was a multi-center, randomized, double-blind, placebo-controlled trial. Participants had persistent dyspeptic symptoms and underwent upper gastrointestinal endoscopy in a secondary care hospital to exclude organic abnormalities. They were randomly assigned to receive 8 weeks of treatment with either venlafaxine XR (2 weeks 75 mg once daily, 4 weeks 150 mg once daily, and 2 weeks 75 mg once daily) or placebo. Symptoms, health-related quality of life, anxiety, and depression were assessed before and at 4, 8, 12, and 20 weeks after inclusion. Results: One hundred sixty patients were randomized; 56% and 73% of participants completed treatment with venlafaxine or placebo, respectively, according to protocol. There was no difference in proportions of symptom-free patients after 8 weeks of treatment or at 20 weeks after inclusion, with venlafaxine in comparison to placebo (37% and 39%, respectively; odds ratio [OR], 0.8; 95% confidence interval [CI], 0.3-2.1; and 42% and 41%, respectively; OR, 3.1; 95% CI, 0.9-12.6). Per-protocol analysis did not reveal any differences between venlafaxine and placebo either (38% and 39% symptom-free, respectively; OR, 1.0; 95% CI, 0.4-2.4 at 8 weeks). Conclusions: Treatment with the selective serotonin and norepinephrine reuptake inhibitor venlafaxine is not more effective than placebo in patients with functional dyspepsia.