Hypericum extract worse than placebo in a trial in irritable bowel syndrome patients

Saito YA, Rey E, Almazar‐Elder AE, Harmsen WS, Zinsmeister AR, Locke GR, Talley NJ. A randomized, double‐blind, placebo‐controlled trial of St John’s wort for treating irritable bowel syndrome. Am J Gastroenterol 2010; 105: 170–7.     

Calcium polycarbophil compared with placebo in irritable bowel syndrome

Calcium polycarbophil was compared with placebo in 23 patients with irritable bowel syndrome in a six-month, randomized double-blind crossover study. Patients received polycarbophil tablets at a dosage of 6 g/day (twelve 0.5-g tablets) or matching placebo tablets. At study end, among patients expressing a preference, 15 of 21 (71%) chose polycarbophil over placebo for relief of the symptoms of irritable bowel syndrome. Statistically significant differences favouring polycarbophil were found among the following patient subgroups: 15 (79%) of 19 with constipation; all six with alternating diarrhoea and constipation; 13 (87%) of 15 with bloating; and 11 (92%) of 12 with two or more symptoms. Polycarbophil was rated better than placebo in monthly global responses to therapy. Patient diary entries showed statistically significant improvement for ease of passage with polycarbophil. Polycarbophil was rated better than placebo for relief of nausea, pain, and bloating. The data suggest that calcium polycarbophil can benefit irritable bowel syndrome patients with constipation or alternating diarrhoea and constipation and may be particularly useful in patients with bloating as a major complaint.     

Randomised clinical trial: Bifidobacterium bifidum MIMBb75 significantly alleviates irritable bowel syndrome and improves quality of life--a double-blind, placebo-controlled study

Aliment Pharmacol Ther 2011; 33: 1123–1132

Summary

Background Recent research suggests that an imbalance of the intestinal microbiota and a dysfunctional intestinal barrier might trigger irritable bowel syndrome (IBS). As probiotics have been reported to restore the intestinal microbiota and the gut barrier, the therapeutic potential of probiotics within IBS became of strong interest. Aim To assess the efficacy of Bifidobacterium bifidum MIMBb75 in IBS. Methods A total of 122 patients were randomised to receive either placebo (N = 62) or MIMBb75 (N = 60) once a day for 4 weeks. The severity of IBS symptoms was recorded daily on a 7‐point Likert scale. Results MIMBb75 significantly reduced the global assessment of IBS symptoms by ?0.88 points (95% CI: ?1.07; ?0.69) when compared with only ?0.16 (95% CI: ?0.32; 0.00) points in the placebo group (P < 0.0001). MIMBb75 also significantly improved the IBS symptoms pain/discomfort, distension/bloating, urgency and digestive disorder. The evaluation of the SF12 sum scores showed a significant gain in quality of life within the bifidobacteria group. Furthermore, adequate relief was reported by 47% of the patients in the bifidobacteria and only by 11% of the patients in the placebo group (P < 0.0001). Overall responder rates were 57% in the bifidobacteria group but only 21% in the placebo group (P = 0.0001). MIMBb75 was well tolerated and adverse events were not different from placebo. Conclusions Bifidobacterium bifidum MIMBb75 effectively alleviates global IBS and improves IBS symptoms simultaneously with an improvement of quality of life. Considering the high efficacy of MIMBb75 in IBS along with the good side‐effect profile, MIMBb75 is a promising candidate for IBS therapy.

     

Randomised clinical trial: the safety and efficacy of AST-120 in non-constipating irritable bowel syndrome - a double-blind, placebo-controlled study

Aliment Pharmacol Ther 2011; 34: 868–877

Summary

Background There is a need for safe and effective treatment options for irritable bowel syndrome (IBS). AST‐120 (spherical carbon adsorbent) is a non‐absorbed, carbon‐based adsorbent with extensive adsorbing capability for histamine, serotonin and other substances implicated in IBS pathogenesis. Aim To evaluate the efficacy and safety of AST‐120 in non‐constipating forms of IBS. Methods This randomised, double‐blind, placebo‐controlled trial conducted in the US and Belgium enrolled 115 male and female patients fulfilling Rome III criteria for IBS; individuals with predominantly constipation symptoms were excluded. Subjects were randomised to AST‐120 2 g tds or placebo for an 8‐week double‐blind treatment period, followed by a 2‐week single‐blind placebo washout and 8‐week single‐blind active treatment. The primary efficacy endpoint was the proportion of subjects achieving at least a 50% reduction in the number of days with abdominal pain compared with baseline. Results At Week 4, 26.8% of subjects treated with AST‐120 responded on the primary endpoint vs. 10.2% in the placebo arm (P = 0.029); at Week 8 response rates were 32.1 and 25.4% respectively (NS). More AST‐120 treated subjects experienced improvement in bloating and stool consistency. These benefits abated when AST‐120 was replaced by placebo, and resumed once AST‐120 was restarted. The frequency of adverse events with AST‐120 were less than or equal to placebo. Conclusions AST‐120 is safe and well‐tolerated and reduces pain and bloating in non‐constipating IBS, although beneficial effects may be limited in duration. AST‐120 represents a locally acting, non‐absorbed, novel treatment for IBS and warrants further studies.     

Randomised clinical trial: the clinical effects of a novel neurokinin receptor antagonist, DNK333, in women with diarrhoea-predominant irritable bowel syndrome

Background Neurokinin receptors may play an important role in the visceral hypersensitivity and exaggerated motor/secretory activity associated with diarrhoea‐predominant irritable bowel syndrome (IBS‐D). Aim To evaluate the effects of DNK333, a novel neurokinin antagonist, in women with IBS‐D. Methods In two consecutive phase II studies, women with IBS‐D were randomised to twice‐daily (b.d.) DNK333 25 mg, DNK333 100 mg or placebo for 2 weeks (Trial 1), or DNK333 25 mg b.d. or placebo for 4 weeks (Trial 2). Primary efficacy variables studied were change from baseline of stool form at week 2, and satisfactory relief of IBS‐related abdominal pain/discomfort and global IBS‐D symptoms. Secondary efficacy variables, pharmacokinetics and safety were also evaluated. Results In total, 315 subjects were randomised. There were no statistically significant differences between treatment groups for the primary efficacy variables. However, analysis of combined data from both trials revealed significant differences favouring DNK333 25 mg over placebo for satisfactory relief of IBS‐related abdominal pain/discomfort and global IBS‐D symptoms. Trends favouring improvement with DNK333 25 mg vs. placebo were seen for all secondary efficacy variables. DNK333 had a safety profile similar to placebo. Conclusions DNK333 25 mg b.d. appears to be effective and well tolerated in women with IBS‐D. Further studies with neurokinin antagonists are warranted.