Polyethylene Glycol (PEG) Versus Sennosides Study in Opioid-Induced Constipation in Cancer Patients

A Randomized, Double Blind, Double-dummy, 2-treatment, 2-period Crossover Comparison of Sennosides and Polyethylene Glycol in Treatment of Opioid-induced Constipation in Outpatients With Cancer

This is a study to compare the efficacy and tolerability of two laxatives for treatment of opioid-induced constipation in adult outpatients with cancer treated at the British Columbia Cancer Pain and Symptom Management/Palliative Care clinics. Each participating patient will be randomly assigned to one of two treatment groups.

One group will be started on a bowel protocol of escalating doses of sennosides, plus a dummy polyethylene glycol (lactose), and the other will receive dummy sennosides capsules (lactose) plus polyethylene glycol, with the same dosing protocol. After three weeks of one active treatment the patients will switch to the alternate active product and dummy preparation. The total duration for the study will be 6 weeks for each patient.

Inclusion Criteria:

1. Adult patient (18 years and above) with diagnosis of cancer.
2. Patient requires treatment or prevention of constipation.
3. Patient is able to communicate effectively with staff.
4. Expected prognosis more than 12 weeks.
5. On or starting opioid therapy

Exclusion Criteria:

1. Patient unable to take oral medication.
2. Allergy or previous intolerance to PEG or sennosides.
3. Lactose intolerant.
4. Contraindication to PEG or sennosides.
5. Known or suspected bowel obstruction or ileus.
6. Colostomy or ileostomy.
7. Inflammatory bowel disease.
8. Hospitalisation expected within the study period.
9. Patient unable to complete the study diary in English.