A comparison of nalbuphine and pethidine for postoperative pain relief after orthopaedic surgery.

Nalbuphine hydrochloride (Nubain; Du Pont Pharmaceuticals), a synthetic agonist-antagonist analgesic, in a dose of 20 mg was compared with pethidine 100 mg in 60 patients after elective surgery in a random double-blind study. Both drugs were given intramuscularly on the first day after surgery. The pain intensity and visual analogue scales would seem to indicate that nalbuphine has a longer duration of action than pethidine (P less than 0,05). The respiration rates in the pethidine group were significantly more depressed 30 minutes after the injection than in the nalbuphine group (P less than 0,05). Nalbuphine caused less depression of both systolic and diastolic blood pressure at both 30 and 60 minutes (P less than 0,001). The results of the study show that nalbuphine, in the dose used here, may prove to be a useful substitute for pethidine.