Comparison of nalbuphine, pethidine and placebo as premedication for minor gynaecological surgery.

In a randomized double-blind placebo-controlled trial involving 80 patients nalbuphine 10 mg and 20 mg were compared with pethidine 100 mg and a placebo given i.m. at least 90 min before minor gynaecological surgery. Nalbuphine proved a suitable alternative to pethidine, producing beneficial sedation which was maximum at 60 min after injection. Both nalbuphine and pethidine reduced the excitatory sequelae of methohexitone induction. Increasing the dose of nalbuphine from 10 mg to 20 mg produced no significant additional sedation or intraoperative benefit. Short-lived pain at the injection site was a feature of the use of nalbuphine in either dose. The main disadvantage of nalbuphine was nausea and vomiting of delayed onset, the frequency of which was similar after either dose.