Multicenter, 4-week, double-blind, randomized, placebo-controlled trial of sodium picosulfate in patients with chronic constipation.

Objectives: Although it has been used as a laxative for many years, high-quality trials assessing the efficacy of the laxative sodium picosulfate (SPS) are lacking. The purpose of this study was to assess the efficacy and safety of 4-week treatment with SPS in patients with functional constipation as defined by the Rome III diagnostic criteria.

Methods: This study was a randomized, double-blind, placebo-controlled, parallel-group study in 45 general practices in Germany. A total of 468 patients with chronic constipation presenting to their general practitioner and fulfilling the Rome III diagnostic criteria were screened. After a 2-week baseline period, 367 patients were randomized to either SPS drops or matching placebo in a 2:1 ratio for 4 weeks. Dose titration was permitted throughout treatment. Patients without a bowel movement for more than 72 h were allowed to use a "rescue" bisacodyl suppository. The primary end point was the mean number of complete spontaneous bowel movements (CSBMs) per week. A spontaneous bowel movement (SBM) was defined as a stool not induced by rescue medication, whereas a CSBM was defined as an SBM associated with a sensation of complete evacuation.

Results: The mean number (+/-s.e.) of CSBMs per week increased from 0.9+/-0.1 to 3.4+/-0.2 in the SPS group and from 1.1+/-0.1 to 1.7+/-0.1 in the placebo group (P<0.0001). The percentage of patients reaching an increase of > or =1 in the mean number of CSBMs per week compared to baseline was 65.5% vs. 32.3%, respectively (P<0.0001). The percentage of patients reaching a mean number of at least three CSBMs per week was 51.1% in the SPS group and 18.0% in the placebo group (P<0.0001). After 24 h, approximately 69% of patients in the SPS group and 53% in the placebo group had their first SBM. The SPS dose was titrated down during the study by nearly 50% of patients. Assessment of quality of life (QoL) by the constipation-related Patient Assessment of Constipation (PAC)-QoL questionnaire showed significant improvement in SPS-treated patients compared to the placebo group.

Conclusions: Treatment of chronic constipation with SPS improves bowel function, symptoms, and QoL and is well tolerated. The dose can be adjusted individually while maintaining benefit.