Mesalamine moderately useful in IBS, but confidence in evidence is low

The authors of a recent meta-analysis wrote that guidelines for irritable bowel syndrome (IBS) management should not recommend the drug until adequately powered studies are available.

Mesalamine may be modestly efficacious for global symptoms in patients with irritable bowel syndrome (IBS), particularly IBS with diarrhea (IBS-D), but the quality of the evidence was low, a meta-analysis concluded.

Researchers reviewed randomized controlled trials (RCTs) published until Sept. 14, 2022, that evaluated the efficacy and safety of mesalamine for global IBS symptoms, abdominal pain, bowel habit or stool frequency, and occurrence of any adverse event. The results were published Feb. 27 by Clinical Gastroenterology and Hepatology.

In eight eligible RCTs (820 patients, 432 taking mesalamine), mesalamine was more efficacious than placebo for global IBS symptoms (relative risk [RR] for global symptoms not improving, 0.86; 95% CI, 0.79 to 0.95; number needed to treat, 10; 95% CI, 6 to 27), but not for abdominal pain or for bowel habit or stool frequency. In subgroup analyses, mesalamine was effective for global IBS symptoms in patients who had IBS-D (RR, 0.88; 95% CI, 0.79 to 0.99), but not in patients with other predominant bowel habits or those with IBS after infection. Adverse event rates were similar with mesalamine and with placebo (RR, 1.20; 95% CI, 0.89 to 1.63) but were reported in only five trials.

There is a need for adequately powered high-quality RCTs of mesalamine in IBS, the authors wrote, noting that since confidence in the evidence was low, they would not suggest that guidelines for IBS management recommend mesalamine. “However, the drug did not appear to be associated with an excess of adverse events in the RCTs that reported these data. Patients with IBS-D have limited treatment options, and there are safety concerns with licensed drugs such as alosetron or eluxadoline,” they wrote. “Therefore, mesalamine could be a safe and efficacious treatment option for some patients.” They called for additional trials recruiting only patients with IBS-D and said that researchers may need to report the efficacy of mesalamine by postinfection status.