Clinical trial: the efficacy of alverine citrate/simeticone combination on abdominal pain/discomfort in irritable bowel syndrome--a randomized, double-blind, placebo-controlled study.

Background: Alverine citrate and simeticone combination has been used for almost 20 years in irritable bowel syndrome (IBS), but supportive scientific evidence of efficacy was limited.

Aim: To evaluate the efficacy of alverine citrate and simeticone combination in patients with IBS-related abdominal pain/discomfort.

Methods: A total of 412 IBS patients meeting ROME III criteria were included in this double-blind randomized placebo-controlled study if their abdominal pain/discomfort intensity was at least 60 mm on a 0-100 mm visual analogue scale (VAS) during a 2-week run-in treatment-free period. Patients were randomly assigned through the use of Interactive Voice Response System to receive either alverine citrate 60 mg with simeticone 300 mg three times daily or matching placebo for 4 weeks.

Results: The full analysis set included 409 patients (71.4% female: mean age: 46.2 +/- 13.9 years). At week 4, alverine citrate and simeticone group had lower VAS scores of abdominal pain/discomfort (median: 40 mm vs. 50 mm, P = 0.047) and higher responder rate (46.8% vs. 34.3%, OR = 1.3; P = 0.01) as compared with placebo group. Patient receiving alverine citrate and simeticone reported greater global symptom improvement compared with those receiving placebo (P = 0.0001). Reported adverse events were similar in both groups.

Conclusion: Alverine citrate/simeticone combination was significantly more effective than placebo in relieving abdominal pain/discomfort in patients with IBS.