Comparison of oral ketorolac, intramuscular morphine, and placebo for treatment of pain after orthopedic surgery.

ABSTRACT

Using a randomized, double-blind, placebo-controlled, parallel, single-dose, single-center, 6-hour study, we compared the analgesic response and tolerability of oral ketorolac tromethamine and intramuscular morphine sulfate and placebo. The study group comprised 176 patients with moderate, severe, or very severe pain after hip or knee surgery at a teaching hospital. Patients received either 10 mg of ketorolac orally, 10 mg of morphine intramuscularly, 5 mg of morphine IM, or placebo. Patients rated pain intensity at baseline and pain intensity and pain relief at 30 minutes, 1 hour, and hourly thereafter for 6 hours. At study completion, we evaluated overall patient ratings of pain relief and occurrence of adverse events. Summed pain intensity difference scores and total pain relief scores showed the active medications to be significantly superior to placebo and not significantly different from each other. The 10-mg dose of morphine showed a small advantage over ketorolac in peak analgesic effect, but the onset of pain relief was comparable among the active agents. The incidence of adverse events among the active-treatment groups was similar, though there was a numerical trend favoring ketorolac over 10 mg of morphine. We found oral ketorolac to be an effective alternative to parenteral opioids for the treatment of pain after hip or knee surgery in patients who can tolerate oral medication.