Treatment of Chronic Moderate-to-severe Non-malignant Pain with Polymer-coated Extended-release Morphine Sulfate Capsules

Objective: To demonstrate the efficacy and tolerability of polymer-coated extended-release morphine sulfate (P-ERMS)(KADIAN) for the treatment of chronic, moderate-to-severe, non-malignant pain in a community-based outpatient population not satisfactorily relieved with their current therapies.

Design: Phase IV, prospective, randomized, open-label, blinded endpoint.

Participants: Adults (N = 1428) with chronic, moderate-to-severe, non-malignant pain with visual numeric scale scores >or= 4 (0 = no pain; 10 = worst pain).

Interventions: Patients were randomized to P-ERMS once daily in AM or PM for a 4-week treatment period. Dose increases were allowed; however, switching to twice-daily dosing was reserved until week 2.

Main Outcome Measures: Improvement from baseline in pain and sleep scales (0-10) (after weeks 2 and 4), quality of life (physical and mental component summary scores of the SF-36v2 Health Survey) (week 4), and patient (weeks 2 and 4) and clinician (week 4) assessments of current therapy (-4 to +4). Patient satisfaction was assessed again 1 month after the study.

Results: Approximately 70% of patients completed the study, with 2.4% (n = 34) discontinuing due to lack of efficacy, and 9.6% (n = 136) discontinuing due to an adverse event. Improvements were seen in pain and sleep scores, physical and mental component scores of the SF-36v2, and patient and clinician global assessment scores (p < 0.0001, all assessments). Patients attained similar results regardless of AM vs. PM dosing. More than half (55.4%) of patients were maintained on once-daily therapy, with the remainder on a twice-daily regimen, in accordance with the prescribing information. Most adverse events (71.6%) were mild to moderate in severity, the most common being constipation (11.6%) and nausea (9.2%). One-month follow-up indicated continued satisfaction with P-ERMS vs. previous medication (p < 0.0001).

Conclusions: P-ERMS was efficacious and well tolerated in patients with chronic, moderate-to-severe, non-malignant pain when used once or twice daily.