Pinaverium bromide plus simethicone improves abdominal pain, bloating in IBS

The combination of pinaverium bromide 100 mg plus simethicone 300 mg is effective in the treatment of bloating (PB+S) and abdominal pain in patients with active irritable bowel syndrome (IBS), a study has shown. The effect of combined therapy on the frequency of stool consistency was significant in IBS with constipation (C) and mixed-type (M) IBS.

“This is not the first trial using combination therapy for IBS, and our results are in agreement with those of an on-demand trial using alverine citrate also combined with simethicone, showing similar effects on bloating and abdominal pain,” the researchers said. [Int J Clin Pract 2014;68:245-254]

A total of 285 patients (mean age, 36.5 years; 83 percent female) with abdominal pain or discomfort for at least 2 days within the week prior to baseline assessment were randomized to receive at least one dose of PB+S (n=140) or placebo (n=145).

Overall symptom improvement, assessed weekly by the patient (Likert scale), was the primary endpoint. Secondary endpoints included weekly improvement in the severity of abdominal pain and bloating assessed both by patients (10-cm visual analogue scale) and researchers (Likert scale), and frequency of Bristol Scale stool types (consistency) evaluated by patients and the IBS Quality of Life score.

No significant between-group difference was observed in the primary endpoint (p=0.13), but PB+S was superior to placebo in improving abdominal pain (effect size, 31 percent; p=0.038) and bloating (effect size, 33 percent; p=0.019). [J Clin Gastroenterol 2020;54:e30-e39]

The best improvement in the frequency of stool types occurred in patients with IBS-C and IBS-M who were treated with PB+S. There were no differences in IBS Quality of Life scores and adverse events.

“The significant effect on bloating with PB+S independently of the bowel habit subtype shown … is an important one, as few treatments have proven to be effective on this common symptom, and all of them including newer treatments are effective on specific IBS subtypes such as linaclotide in IBS-C,” the researchers said. [Aliment Pharmacol Ther 2011;33:1071-1086; Am J Gastroenterol 2012;107:1702-1712; Aliment Pharmacol Ther 2013;37:49-61]

The added effect of the antifoaming S with the smooth muscle relaxant properties of PB could have driven the improvement of bloating. This was consistent with a systematic review and meta-analysis of antispasmodics available in Mexico, which reported that only the PB+S combination succeeded in the improving bloating. [Rev Gastroenterol Mex 2012;77:82-90]

The present trial was limited by the inclusion of patients within the age range of ≥18 years and ≤50 years, as the efficacy of the combined therapy could not be extrapolated to IBS patients aged >50 years.

“This study supports the concept that a treatment combination is a convenient approach for the treatment of IBS,” the researchers said. “Future analyses in clinical trials should include these kinds of methodologies for efficacy toward understanding the mechanism of improvement according to the IBS subtypes.”