Analysis of the analgesic efficacy of acetaminophen 1000 mg, codeine phosphate 60 mg, and the combination of acetaminophen 1000 mg and codeine phosphate 60 mg in the relief of postoperative pain.

Patients who experienced pain after surgery were administered a single dose of 1 of 3 treatments: acetaminophen 1000 mg, codeine phosphate 60 mg, or a combination of these. Patients rated their pain intensity on ordinal and visual analog scales just prior to medication and at intervals thereafter for up to 5 hours. They also rated pain relief, pain half gone, and any adverse effects. Sum of pain intensity difference and total pain relief scores were analyzed using Dunnett's procedure. The drug combination was statistically superior to codeine as measured by SPID, TOTPAR, pain half gone, and time to remedication. The combination achieved better mean scores than acetaminophen on all efficacy measures, but was (marginally) statistically superior only in pain half gone. No appreciable differences in adverse effects were noted among the treatments. The difficulty of showing the analgesic efficacy of codeine in a single dose trial is discussed.