Synergism between analgesics.

The concept and value of 'multimodal' or 'balanced' analgesia in the treatment of postoperative pain is reviewed. Based upon the relatively few multimodal studies compared to unimodal studies, it is concluded that a combination of analgesics will improve pain relief including movement-associated pain. Since analgesic combination therapy is rational, further studies are needed to evaluate the optimal combination for each surgical procedure, as well as to assess the risk of side effects and need for surveillance in large-scale studies.