The effect of nefopam on morphine overconsumption induced by large-dose remifentanil during propofol anesthesia for major abdominal surgery.

Opioids may activate pain facilitatory systems opposing analgesia. We investigated whether large-dose remifentanil given during IV anesthesia caused postoperative morphine overconsumption and whether nefopam (a centrally acting analgesic) could reduce this. Sixty patients scheduled for abdominal surgery were included in this prospective, randomized study.