Comparative evaluation of efficacy and safety of drotaverine versus mebeverine in irritable bowel syndrome: A randomized double-blind controlled study

BACKGROUND: Drotaverine and Mebeverine are used for alleviating the pain of IBS, but the evidence for their efficacy is scarce. In this randomised control study, we evaluated and compared their efficacy in improving severity, frequency of pain and its associated symptoms. METHODS: Patients fulfilling the ROME III criteria of IBS were evaluated in this randomised control trial during 4 weeks of treatment. Group A (n = 100) received 80 mg Drotaverine and Group B (n = 100) received 135 mg Mebeverine three times a day, 1 hour before meals. Primary outcome measure was, the reduction in severity of pain (>30% reduction) assessed by VAS (0 to 10 scale) & PSS (patient symptoms scores). RESULTS: The pain severity score fell from 6.02 to 4.8 on day 3 in Group A as compared to decrease from 6.72 to 6.62 in Group B (p < 0.01). This significant reduction in pain severity was observed till the end of the study, reducing from 6.02 to 1.78 (74% reduction) in Group A compared to 6.72 to 3.62 (46.1% reduction) in Group B (p < 0.05). There was a significant reduction in pain frequency, straining on stool, a change in one score in Bristol stool chart (BSC), achievement of complete spontaneous smooth bowel movement in Group A, compared to Group B patients. A significant improvement in Patient's evaluation of Global Assessment of Symptoms (p < 0.05) and Patient Assessment of Constipation – Quality Of Life (PAC-QOL) (p < 0.01) was observed in Group A compared to Group B. CONCLUSION: Drotaverine was significantly superior in efficacy as compared to Mebeverine in alleviating pain severity (starting from day 3), frequency and stools-elated symptoms of IBS.