A randomized, controlled trial to compare the efficacy of oral rofecoxib and intra-muscular diclofenac sodium for the treatment of post-operative pain after major orthopedic surgery

Objective: To compare the efficacy of oral rofecoxib, intramuscular diclofenac and placebo in the amount of PCA morphine used during postoperative orthopedic surgery period. Design: Randomized (1:1:1) double-blind controlled trial Setting: King Chulalongkorn Memorial Hospital Methods: One hundred and two healthy patients undergoing major orthopedic surgery were recruited for the study and 96 patients completed the study. Patients were randomized into three treatment groups; placebo group (n=31) received oral placebo and placebo injection, rofecoxib group (n=32) received 50 mg preoperative oral rofecoxib and placebo injection, and diclofenac group (n=33) received oral placebo and post-operative intramuscular diclofenac injection 12 hourly. All patient received intravenous morphine by patient controlled analgesia (PCA) system. Amount of morphine used, numerical pain score and patient satisfaction were recorded for 24 hours. Adverse event was also monitored. Results: There was no statistical significant different of the amount of PCA morphine used between rofecoxib group and diclofenac group (p=0.762). The amount of PCA morphine used at 24 hours in patients who received oral rofecoxib and placebo was significantly different (17.5 mg vs 35 mg, p=0.003, 50% less) and the amount of PCA morphine used at 24 hours in patients who received diclofenac injection and patients in placebo group was significantly different (20 mg vs 35 mg, p<0.001, 43% less). Numerical pain scores between rofecoxib group and placebo group were not different. Numerical pain scores between diclofenac group and placebo group were significantly different at 4 hour post-operatively (p=0.003). Ninety eight percent of the patients reported satisfactory score between "satisfy", "very satisfy" and "most satisfy" to the treatment of postoperative pain. No serious adverse event occurred and there were 11% adverse events (6% nausea, 2% hypotension, 1% dizziness, 1% pruritus and 1% dyspepsia). Conclusion: Single dose preoperatively administered rofecoxib is as efficacious for the treatment of postoperative pain as post-operative injection of diclofenac sodium 12 hourly in the first 24 hours after major orthopedic surgery