Earnest, David L.

Objective Over half of patients with IBS have either diarrhoea (IBS-D) or a mixed stool pattern (IBS-M). The relative efficacy of licenced pharmacological therapies is unclear in the absence of head-to-head trials. We conducted a network meta-analysis to resolve this uncertainty. Design We searched MEDLINE, Embase, Embase Classic, the Cochrane central register of controlled trials, and Clinicaltrials.gov through January 2019 to identify randomised controlled trials (RCTs) assessing the efficacy of licenced pharmacological therapies (alosetron, eluxadoline, ramosetron and rifaximin) in adults with IBS-D or IBS-M. Trials included in the analysis reported a dichotomous assessment of overall response to therapy, and data were pooled using a random effects model. Efficacy and safety of all pharmacological therapies were reported as a pooled relative risk with 95% CIs to summarise the effect of each comparison tested. Treatments were ranked according to their p score. Results We identified 18 eligible RCTs (seven alosetron, five ramosetron, two rifaximin and four eluxadoline), containing 9844 patients. All were superior to placebo for the treatment of IBS-D or IBS-M at 12 weeks, according to the Food and Drug Administration (FDA)-recommended endpoint for trials in IBS. Alosetron 1 mg twice daily was ranked first for efficacy, based on the FDA-recommended composite endpoint of improvement in both abdominal pain and stool consistency, effect on global symptoms of IBS and effect on stool consistency. Ramosetron 2.5µg once daily was ranked first for effect on abdominal pain. Total numbers of adverse events were significantly greater with alosetron 1 mg twice daily and ramosetron 2.5µg once daily, compared with placebo. Rifaximin 550 mg three times daily ranked first for safety. Constipation was significantly more common with all drugs, except rifaximin 550 mg three times daily. Conclusion In a network meta-analysis of RCTs of pharmacological therapies for IBS-D and IBS-M, we found all drugs to be superior to placebo, but alosetron and ramosetron appeared to be the most effective.

Background: Alosetron is approved to treat women with severe IBS and diarrhea (IBS-D) who have failed standard therapy. In our study, we aimed to evaluate alosetron efficacy using new US Food and Drug Administration (FDA) endpoints and utilization in clinical practice. Methods: This prospective, open-label, multicenter, observational 12-week study evaluated women with severe IBS-D enrolled in the alosetron prescribing program. The coprimary FDA endpoints were changes from baseline in stool consistency and abdominal pain severity. Responders achieved a 30% decrease compared with baseline in weekly average of the worst abdominal pain in the past 24 h, and a 50% or greater reduction from baseline in the number of days/week with at least one stool of type 6 (mushy) or type 7 (watery) consistency. Secondary endpoints included changes from baseline in stool frequency, fecal urgency and fecal incontinence. Results: Enrolled patients ( n = 192) were primarily White (90.6%), with a mean age of 44.5 years. Patient and physician rating of IBS severity was between moderate and severe (85.9% concordance, Spearman coefficient 0.429, p < 0.0001). Alosetron 0.5 mg twice daily (82.8%) was the most common dosing regimen. A total of 152 alosetron-treated patients completed the study. Of 105 fully evaluable patients, 45% met the FDA composite endpoint responder criteria for ⩾50% of the study period. Improvements in all individual symptoms were statistically significant compared with baseline. There were no serious adverse events, cases of colonic ischemia, or complications of constipation. Conclusion: In a clinical practice setting study, alosetron demonstrated treatment success using a rigorous FDA composite endpoint and also improved multiple other IBS symptoms, including fecal urgency and incontinence in women with severe IBS-D [ ClinicalTrials.gov identifier: NCT01257477].