Sodium picosulfate in opioid-induced constipation: results of an open-label, prospective, dose-ranging study

Identification of a safe and effective dose of the laxative sodium picosulfate was investigated in a single-centre, open-label study of 23 patients (age 40-81 years) receiving > or =60 mg/day morphine sulphate and experiencing constipation. A starting dose of 5, 10 or 15 mg sodium picosulfate (1 mg/mL solution) was administered, based on the patient's clinical status at entry and recent requirements for laxatives. Dose titration was permitted (+/-2.5 or 5 mg increments), to a maximum daily dose of 60 mg. Bowel movements, concomitant medication and need for suppositories or enemas were recorded in daily diaries. Sixteen patients withdrew before the end of the planned 14-day treatment period because of deterioration of the underlying condition. Sodium picosulfate was well-tolerated. Serious adverse events were all related to the underlying condition. A satisfactory response (normal stool consistency, not requiring enemas, suppositories or manual evacuation, no significant adverse event) was achieved in 15/20 evaluable patients. The median daily dose to achieve this was 15 mg (range: 5-30 mg) and the median time to first bowel movement after dosing was 11.75 hours (range: 6-22.5 hours). There was no clear relationship between the opioid dose and the optimum dose of sodium picosulfate, confirming that individual dose titration is necessary.