PARACETAMOL WITH AND WITHOUT CODEINE IN ACUTE PAIN - A QUANTITATIVE SYSTEMATIC REVIEW

In order to assess the analgesia obtained from single oral doses of pa racetamol alone and in combination with codeine in postoperative pain, we conducted a systematic review of randomised controlled trials. We found 31 trials of paracetamol against placebo with 2515 patients, 19 trials of paracetamol plus codeine against placebo with 1204 patients and 13 trials of paracetamol plus codeine against the same dose of par acetamol with 874 patients. Pain relief information was extracted, and converted into dichotomous information (number of patients with at le ast 50% pain relief). Wide variations in responses to placebo (0-72%) and active drug (3-89%) were observed. In postoperative pain states pa racetamol 1000 mg alone against placebo had an number-needed-to-treat (NNT) of 3.6 (3.0-4.4) and paracetamol 600/650 mg alone an NNT of 5.0 (4.1-6.9). Paracetamol 600/650 mg plus codeine 60 mg against placebo h ad a better NNT of 3.1 (2.6-3.8), with no overlap of 95% confidence in tervals with paracetamol 600/650 mg alone. In direct comparisons of pa racetamol plus codeine with paracetamol alone the additional analgesic effect of 60 mg of codeine added to paracetamol was 12 extra patients in every 100 achieving at least 50% pain relief. In indirect comparis ons of each with placebo it was 14 extra patients per 100. This was an NNT for adding codeine 60 mg of 9.1 (5.8-24). The results confirm tha t paracetamol is an effective analgesic, and that codeine 60 mg added to paracetamol produces worthwhile additional pain relief even in sing le oral doses. (C) 1997 International Association for the Study of Pai n.