Multimodal analgesia is a technique whereby a combination of analgesic drugs with different modes of action can be used to improve analgesia and decrease adverse effects by virtue of synergism. Postoperatively, with adjunctive analgesia, PCA morphine consumption as well as the side effects may be reduced. Non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to be opioid sparing and decrease the adverse effects of PCA morphine. A recent review showed that acetaminophen combined with PCA could induce a significant opioid-sparing effect but the incidence of PCA morphine related side effects were not reduced.