Analgesic efficacy and safety of two oral controlled-release morphine preparations in orthopedic postoperative pain

Abstract

This single-dose, double-blind, randomized, parallel-group study compared the analgesic efficacy and safety of MS Contin (MSC) and Oramorph SR (OSR), two controlled-release preparations of oral morphine sulfate, in patients following orthopedic surgery. One hundred patients received MSC 30 mg, MSC 60 mg, or OSR 60 mg (two 30-mg tablets) when postoperative pain became moderate or severe. Patients self-rated pain intensity and relief on categorical (CAT) and visual analogue scales (VAS) hourly for up to 12 hours. MSC 60 mg produced the greatest peak analgesic effect and was more efficacious than OSR 60 mg through the sixth hour, with statistical significance achieved at 1, 2, and 3 hours postdosage. Compared with OSR 60 mg, both MSC dosages provided significantly more rapid times to peak effect by CAT and VAS ratings. The OSR group experienced almost twice as many adverse events as did the two MSC groups and also reported somnolence and dizziness more frequently. MSC 60 mg provided more rapid and greater peak analgesia with fewer adverse effects than did OSR 60 mg.