Analysis of the impact on efficacy of lubiprostone dose reduction to manage adverse events in the treatment of chronic constipation in Japan

Objective To compare outcomes between two doses of lubiprostone in patients with chronic constipation (CC), to assess whether dose reduction affects efficacy.Methods This open-label exploratory study involved 146 patients with CC treated initially with lubiprostone 24 mcg twice daily for a planned duration of 4 weeks. Patients who experienced adverse events (AEs) had their dose reduced to 12 mcg twice daily (for 4 weeks).Results Lubiprostone dose was unchanged in 104 patients and reduced due to AEs in 42 patients. Significant differences in the mean number of bowel movements per week favored the dose-reduced group at Week 1 and end of follow-up. No between-group differences were observed over time for mean number of days per week with bowel movements or mean Bristol Stool Form Scale scores. Symptoms of abdominal bloating, strained defecation, and sensation of incomplete evacuation improved in both groups. Before dose reduction, nausea was reported by 64.3% and diarrhea by 45.2% of patients in the dose-reduced group; after dose reduction, no patients reported nausea and one patient reported diarrhea.Conclusion Dose reduction of lubiprostone reduced the incidence of AEs, with no compromise to efficacy, and may be a suitable approach for patients who develop AEs during treatment.