Comparison of intravenous diclofenac, indomethacin and oxycodone as post-operative analgesics in patients undergoing knee surgery.

The non-steroidal anti-inflammatory drugs diclofenac, indomethacin and oxycodone were compared in the treatment of pain after arthroscopy or arthrotomy of the knee in a double-blind, randomized trial. A single and, if needed, a repeated dose of one of the following six dose and drug alternatives was given intravenously for post-operative pain relief: diclofenac 37.5 mg or 75 mg, indomethacin 25 mg or 50 mg and oxycodone 5 mg or 10 mg. Oxycodone 5 mg i.v. was used as a rescue medication whenever the patient needed further pain relief after the two doses of the trial drugs. The observation period was 14 h. In the diclofenac group the patients needed significantly less trial and rescue analgesics than in the indomethacin (P less than 0.001) and oxycodone (P less than 0.05) groups, the latter groups being equal in this respect. Both the duration from the first trial drug infusion to the second trial medication and to the first rescue medication were significantly longer in the diclofenac group than in the indomethacin group (P less than 0.05 and less than 0.01, respectively).