Wirz, S., Nadstawek, J., Elsen, C., Junker, U., & Wartenberg, H.C. (2012). Laxative management in ambulatory cancer patients on opioid therapy: A prospective, open-label investigation of polyethylene glycol, sodium picosulphate and lactulose. European Journal of Cancer Care, 21, 131–140.

To determine whether variable effectiveness exists in the use of polyethylene glycol (PEG), sodium picosulphate (SPS), and lactulose in ambulatory outpatients with cancer on opioid therapy.

Eligible patients were assigned to three treatment groups. A fourth group comprised patients who had discontinued laxative therapy (NL). Laxative groups were treated for a minimum of 28 days prior to data collection with mu agonist and assigned laxative. Prescribers were free to choose the laxative. The standard doses were PEG 13.1 g per day, SPS 10 mg per day, and lactulose 10 g per day. An increase in dose was allowed if participants were directed to do so by the prescriber.

During the five-day data collection phase, investigators assessed participants daily on mobility and pain assessment. Constipation was assessed by documentation of defecation rates, number of participants with lack of bowel movement for more than 72 hours, subjective intensity of constipation using a numeric scale, and consumption of laxatives.

Average defecation rate of all patients was calculated as defecations per patient per five days. The number of patients reporting nausea or emesis also was documented. The daily doses of the original opioid (oral morphine, hydromorphone, oxycodone, tramadol, or transdermal fentanyl) were transferred into morphine equivalent doses for uniform comparison.

• The study reported on a sample of 348 patients.
• Mean patient age was 62.4 years in the PEG group, 62.2 years in the SPS group, 65.6 years in the lactulose group, and 58.3 years in the NL group.
• Demographic and medical data were similar in all groups.
• The sample was 60% male and 40% female.
• Key disease characteristics were cancer-related pain, opioid therapy with mu agonists (equivalent doses of oral morphine, hydromorphone, oxycodone, tramadol, or transdermal fentanyl), ambulatory treatment, patient cooperation, and Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 3.
• Patients were excluded from the study if they had used opioid antagonists, been referred for nonambulatory treatment, diarrhea at the beginning of therapy, disease likely to cause diarrhea (e.g., pancreatic cancer), opioid dose variations, conditions linked to opioid dose variations (e.g., breakthrough pain), communication deficits, hepatic or renal impairment, current chemotherapy or radiation therapy, nonambulatory status, terminal stage of disease, infection, prior history of drug or alcohol addiction or abuse, concurrent treatment with laxatives other than study medication, used more than a single laxative, partial agonists, and antagonist/agonist combinations.

• Single site
• Outpatient
• Pain Clinic, University Hospital, Bonn, Germany

• Patients were undergoing chronic pain management for cancer diagnoses.
• The study has clinical applicability for palliative care.
   

This was a controlled, prospective, open-label study.

• ECOG Performance Status for mobility
• European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ) for pain assessment
• Constipation Assessment Tool
• Numerical Rating Scale (NRS) for constipation and pain

• No patients in the study discontinued opioid therapy.
• NRS values for pain were comparable in all groups.
• After 28 days, PEG was the most frequently used laxative (n = 95, 27.3%) compared to SPS (n = 36, 10.3%) and lactulose (n = 32, 9.2%).
• Fifty-three percent of patients (n = 185) discontinued laxative therapy.

In this prospective study, PEG was more frequently prescribed than SPS and lactulose. However, the data did not prove the superiority of PEG over SPS and lactulose for the management of constipation in ambulatory patients with cancer on opioid therapy.

• The study took place at a single site and may be biased in that respect.
• No data exist to support whether opioid-induced constipation is dose-related or substance-related.
• Daily opioid doses in study groups differed significantly (p = 0.011).
• Medications were not blinded.
• Physician preference of PEG over SPS and lactulose may show bias.
• Some antiemetics used may have constipating effects.

No recommendation can be made.