Effect of ramosetron in female patients with irritable bowel syndrome with diarrhea: a phase III long-term study

The long-term safety of administration of ramosetron in female patients with irritable bowel syndrome with diarrhea (IBS-D) is unknown. The aim of this study was to assess the long-term safety, tolerability, and outcomes with the use of ramosetron in female patients with IBS-D.

This was a phase III, open-label, uncontrolled, long-term safety trial of the treatment of female Japanese patients with IBS-D, diagnosed according to the Rome III criteria. A total of 151 patients were given 2.5 μg of ramosetron for 4 weeks, and responders continued the same dose for another 48 weeks. Non-responders at 4 weeks were given 5 μg of ramosetron for 48 weeks. At the end of week 52, 106 patients receiving 2.5 μg and 17 patients receiving 5 μg had completed the study. Safety and efficacy including symptoms and quality of life (QOL) were evaluated.

Concerning safety, no serious adverse event related to ramosetron, specifically ischemic colitis, was observed in patients with either dose of ramosetron. However, constipation occurred in 19.7 % of patients given 2.5 μg and 10.5 % of patients given 5 μg of ramosetron. Ramosetron-treated patients showed high rates of global improvement. Stool consistency, abdominal pain and discomfort, and IBS-QOL were also improved at the last evaluation point.

The results provide evidence of the long-term safety and efficacy of treatment with 2.5 and 5 μg of ramosetron in female patients with IBS-D. Clinicians should be aware that one-fifth of women with IBS-D receiving ramosetron may suffer from constipation during treatment (ClinicalTrials.gov ID: NCT01736423).