Paracetamol and selective and non-selective non-steroidal anti-inflammatory drugs (NSAIDs) for the reduction of morphine-related side effects after major surgery: a systematic review

24-hour morphine consumption decreased by 6.3 mg to 10.9 mg, compared to placebo, when paracetamol, NSAID or COX-2 inhibitors were added to PCA morphine following surgery. Differences in effect between the three drug classes were small and unlikely to be of clinical significance. There does not appear to be a strong case for recommending routine addition of any of the three non-opioids to PCA morphine in the 24 hours immediately after surgery, or for favouring one drug class above the others.