American Academy of Pain Medicine - 23rd annual meeting.

Once-daily extended-release (ER) morphine sulfate (Avinza, Ligand) proved superior to twice-a-day, controlled-release oxycodone HCl (OxyContin, Purdue Pharma) for chronic, moderate-to-severe low back pain in patients naive to sustained-release opioids. Researchers enrolled 392 individuals into an open-label, randomized, parallel-group, multicenter study. The patients underwent titration of their opioid dose for three to six weeks; 132 patients were assigned to receive morphine, and 134 received oxycodone. Opioid dose stabilization, as established by a pain score of less than 4 millimeters (mm) for three consecutive days with two or fewer doses of ibuprofen pain rescue medication per day, was achieved in 266 patients. These subjects were then entered into the eight-week evaluation phase of the study. Patients taking morphine achieved significantly better around-the-clock pain control than those taking oxycodone, as demonstrated by a greater decrease in pain scores from baseline. The patients were at evaluated six, nine, and 12 hours after the morning doses of both opioids (P ≤ .02). Morphine once daily was also more effective than twice-daily oxycodone in terms of quality of sleep achieved, as measured by the Pittsburgh Sleep Quality Index (PSQI) for the entire evaluation period from weeks one to eight (P < .04). The number of ibuprofen rescue medication doses required for breakthrough pain, adjusted for the number of patient days, was lower in the morphine group than in the oxycodone group. The total daily opioid dose was significantly higher with oxycodone than with morphine when oxycodone was converted to morphine equivalents (median, oxycodone 84 mg/day vs. morphone 58 mg/day; P = .0144). The two drugs were comparable in safety and tolerability.