An appraisal of codeine as an analgesic: single-dose analysis.

Codeine, a relatively weak oral narcotic agent, is the most frequently prescribed oral opiate drug. It is also frequently utilized as a control drug in comparative analgesic efficacy studies. These studies are often single dose analysis of pain relief following surgery or childbirth. We conducted a single dose, post-operative analysis of 116 patients who were randomly assigned to receive codeine 60 mg, acetaminophen 600 mg, the combination of codeine and acetaminophen at these doses, or a placebo. Only the combination agent was uniformly superior to placebo. Codeine 60 mg was not consistently superior to placebo in this post-operative single dose analysis. A review of the literature confirms the difficulty in unequivocally establishing the value of codeine as an analgesic, in acceptable oral doses, in the single dose setting. Previous reports, however, suggest that the multiple doses of codeine may afford adequate analgesia. Interpretation of single dose studies with extrapolation to repeated dosing in the practice setting is difficult.