Comparison of repeat doses of intramuscular ketorolac tromethamine and morphine sulfate for analgesia after major surgery.

A multicenter, randomized, double-blind, parallel study in 542 patients with moderate or severe postoperative pain compared the analgesic efficacy and safety of intramuscular ketorolac 30 mg (324 patients), morphine 6 mg (110 patients), and morphine 12 mg (108 patients) administered as needed as often as every 2 hours for a maximum of 20 doses or 5 days. The efficacy of ketorolac 30 mg was comparable to that of morphine 12 mg on every efficacy measure (average pain intensity, average pain relief, mean overall medication rating, and percentage of patients withdrawing because of inadequate relief). Ketorolac was statistically superior to morphine 6 mg for average pain intensity and mean overall rating. Ketorolac-treated patients had fewer adverse events than those who received either morphine dose.