The long and winding road of non steroidal antinflammatory drugs and paracetamol in cancer pain management: a critical review.

The aim of this review was to assess the value of NSAIDs and paracetamol in patients with cancer pain to update a previous review performed ten years ago on this topic. The approach was analytic and based on clinical considerations, rather than on raw evidence, which often does not provide useful information in clinical practice. Both published reports from an extensive search of electronic data bases were collected from January 2001 to December 2011. A free-text search method was used including the following words and their combination: "Anti-inflammatory drugs OR paracetamol OR acetaminophen" AND/OR "cancer pain". Any randomized-controlled trial was considered. Thirteen reports fulfitted inclusion criteria in this systematic review. Randomized trials have been performed by using different modalities of intervention. Single drugs added on opioid therapy or during opioid substitution with opioids as rescue drugs through a patient controlled analgesia, were compared with placebo or between them. Five studies regarded paracetamol. Other four studies assessed the efficacy dipyrone, ketorolac, dexketoprofen, and subcutaneous ketoprofen in cancer pain management, mainly on top of an opioid regimen. The role of paracetamol and NSAIDs in the management of cancer pain still remains controversial. The papers published in this last decade were unable to answer the main questions. There is no proof that they should be used to start the treatment and how long they should be administered when opioid treatment is added on top. While paracetamol seems to be devoid of any benefit, particularly if given at usual clinical doses which should be less than 4 g/day, ketorolac seems to provide an additive analgesic effect even in patients receiving different doses of opioids. The main indication from the analysis of these data is that NSAIDs could be given in patients receiving opioids, evaluating their benefit and weight on opioid therapy in individual patients who have a favorable response to justify a prolonged use.