Comparative effect of paracetamol, NSAIDs or their combination in postoperative pain management: a qualitative review

Background. Quantitative reviews of postoperative pain managementhave demonstrated that the number of patients needed to treatfor one patient to achieve at least 50% pain relief (NNT) is2.7 for ibuprofen (400 mg) and 4.6 for paracetamol (1000 mg),both compared with placebo. However, direct comparisons betweenparacetamol and non-steroidal anti-inflammatory drugs (NSAIDs)have not been extensively reviewed. The aims of this revieware (i) to compare the analgesic and adverse effects of paracetamolwith those of other NSAIDs in postoperative pain, (ii) to comparethe effects of combined paracetamol and NSAID with those ofeither drug alone, and (iii) to discuss whether the adverseeffects of NSAIDs in short-term use are justified by their analgesiceffects, compared with paracetamol. Methods. Medline (1966 to January 2001) and the Cochrane Library(January 2001) were used to perform a systematic, qualitativereview of postoperative pain studies comparing paracetamol (minimum1000 mg) with NSAID in a double-blind, randomized manner.A quantitative review was not performed as too many studiesof high scientific standard (27 out of 41 valid studies, includingall major surgery studies) would have been excluded. Results. NSAIDs were clearly more effective in dental surgery,whereas the efficacy of NSAIDs and paracetamol seemed withoutsubstantial differences in major and orthopaedic surgery, althoughfirm conclusions could not be made because the number of studieswas limited. The addition of an NSAID to paracetamol may conferadditional analgesic efficacy compared with paracetamol alone,and the limited data available also suggest that paracetamolmay enhance analgesia when added to an NSAID, compared withNSAIDs alone. Conclusion. Paracetamol is a viable alternative to the NSAIDs,especially because of the low incidence of adverse effects,and should be the preferred choice in high-risk patients. Itmay be appropriate to combine paracetamol with NSAIDs, but futurestudies are required, especially after major surgery, with specificfocus on a potential increase in side-effects from their combineduse. Br J Anaesth 2002; 88: 199–214