Review of the comparative analgesic efficacy of salicylates, acetaminophen, and pyrazolones.

Use of salicylates, acetaminophen, and pyrazolones has become increasingly complex, extending from the treatment of acute, mild pain to chronic, moderately severe pain. The intensity, rather than the nature, of the pain determines the efficacy of aspirin. A clinical dose-response relationship has been established, and time-effect curves indicate that the total threshold-raising effect depends on dosage frequency. Contrary to popular belief, aspirin and acetaminophen appear to be equipotent and equianalgesic for the relief of most pain. The combination of aspirin (650 mg) plus codeine (30 mg) is only slightly more effective than aspirin alone. The same holds true for acetaminophen (600 mg) plus codeine (60 mg); the efficacy of the combination is only slightly better than that of acetaminophen alone.