Analgesic efficacy of piroxicam in the treatment of postoperative pain. Piroxicam, acetylsalicylic acid and placebo for postoperative pain.
Two randomized, double-blind, single-dose studies were conducted to assess the analgesic efficacy and safety of piroxicam for the treatment of moderate or severe postoperative pain. Study 1 evaluated the analgesic efficacy of piroxicam 20 mg compared with that of codeine sulfate 60 mg and placebo. A final patient population of 149 subjects rated pain intensity and pain relief at one half hour and one hour following treatment and then hourly for six hours, with a global assessment made at the completion of 24 hours. Piroxicam 20 mg was significantly more efficacious than placebo for all analgesic variables, including the sum of the pain intensity differences (SPID), total pain relief (TOTAL), percent SPID, duration of effect, and time to remedication. Codeine 60 mg was significantly superior to placebo for percent SPID and some hourly measures. Piroxicam 20 mg was significantly more effective than codeine 60 mg for percent SPID and a few hourly measures including time to remedication. Study 2 assessed the efficacy of piroxicam 20 mg or 40 mg compared with aspirin 648 mg and placebo. Sixty patients rated their pain intensity and relief hourly for 12 hours and at 24 hours after administration of study medication. Both doses of piroxicam were significantly more effective than placebo from Hours 2 to 12 for pain intensity difference (PID) and relief scores, as well as for SPID and TOTAL. Aspirin was significantly more effective than placebo from Hours 2 to 8 for relief and Hours 2 to 10 for PID as well as SPID and TOTAL. Piroxicam 40 mg was significantly more effective than aspirin 648 mg for SPID, TOTAL, and hourly measures beginning with Hour 6 through Hour 12. Piroxicam 20 mg was significantly better than aspirin for a few hourly measures: Hours 7 to 9 for relief and Hour 7 for PID. In addition, effects of piroxicam 20 mg had a significantly longer duration than aspirin. Similarly, piroxicam 20 mg had a significantly longer time to remedication compared with aspirin and placebo. The results of these studies provide evidence in support of the longer duration of analgesic efficacy of piroxicam compared with codeine or aspirin in patients with postoperative pain. A double-blind comparison of the pain-relieving effect of piroxicam 5 and 10 mg, acetylsalicylic acid 648 mg and placebo was performed in 120 patients with moderate to severe pain on the morning after orthopedic surgery. The changes in pain intensity and pain relief during the 8 h following medication were recorded by a trained nurse observer. 67% of the placebo-treated patients needed rescue drugs compared to 41% of the acetylsalicylic acid, 43% of the piroxicam 5 mg, and 45% of the piroxicam 10 mg treated patients. One to three hours after ingestion of the test drug, the piroxicam and the acetylsalicylic acid groups had significantly improved verbal rating pain intensity scores compared to placebo. In the overall assessment of pain relief at the end of the observation period, the patients' own assessment was significantly superior for acetylsalicylic acid and piroxicam 10 mg compared with placebo. In the observer's assessment of overall pain relief, placebo was significantly inferior to the three other groups. Thus piroxicam 5 mg and 10 mg give relief of pain after orthopedic surgery similar to that given by acetylsalicylic acid 648 mg. The pain-relieving effect of these drugs can be distinguished from placebo, but not from each other. They are not potent enough when pain is moderate to severe after orthopedic surgery.
Piroxicam appears to be of similar efficacy to other NSAIDs and intramuscular morphine 10 mg when used as a single oral dose in the treatment of moderate to severe postoperative pain.