Efficacy and Safety of Drotaverine Hydrochloride in Irritable Bowel Syndrome: A Randomized Double-Blind Placebo-Controlled Study

BACKGROUNDS/AIMS: To study the efficacy and safety of drotaverine hydrochloride (HCl) 80 mg tablet given thrice a day in the symptomatic relief of patients with irritable bowel syndrome (IBS). PATIENTS AND METHODS: The study was a multicentric, randomized, double-blind, placebo-controlled parallel group study performed at three centers. The patients who fulfilled Rome II Criteria of IBS were included in the study. A total of 180 patients with IBS were randomized to drotaverine and placebo treatment groups. Abdominal pain and stool frequency were measured every week in both the groups for all the 4 weeks of treatment duration. Subject Global Assessment of Relief (SGA) of IBS symptoms was assessed at the end of the study. Appropriate statistical analysis was done using SPSS software. STATISTICAL ANALYSIS USED: Mann–Whitney U-test (two-tailed), Wilcoxon signed ranks test, and McNemar tests. RESULTS: Pain frequency decreased significantly (P < 0.01) in 22 (25.9%), 51 (60%), and 66 (77.7%) patients in the drotaverine group, at the end of 2(nd), 3(rd), and 4(th) weeks, respectively, as compared with 8 (9.4%), 18 (21.2%), and 26 (30.6%) in the placebo group. Pain severity scores also decreased significantly in the drotaverine group 66 (77.7%) as compared with placebo 26 (30.6%) after 4 weeks. Drotaverine HCl was shown to provide significant improvement (P < 0.01) in global relief in abdominal pain as perceived by the patient (85.9% vs 39.5%) and the clinician (82.4% vs 36.5%) in the drotaverine group as compared with placebo. There is significant (P < 0.01) improvement in stool frequency in drotaverine HCl treatment group as compared with placebo. The drug is well tolerated without any major side effects. CONCLUSIONS: A 4-week treatment with drotaverine significantly improves abdominal symptoms in patients with IBS.