ABSTRACT : Opioids have been the mainstay of post-operative pain relief. They have many side effects on prolonged usage. Therefore, there was a need for the development of compound with fewer side effects. Nalbuphine is a promising mixed agonist-antagonist. The aim of the study was to compare the efficacy of IV nalbuphine with morphine in terms of potency, duration of analgesia, haemodynamic stability and side effects.

METHODS : Fifty patients belonging to ASA physical status I & II, scheduled for elective abdominal hysterectomy under GA were included .The study was a prospective double blinded randomized trial where the patients were randomly allocated to one of the two groups to receive IV morphine 0.1 mg/kg (Group M) or nalbuphine 0.2 mg/kg (Group N) before induction of GA.

RESULTS : We found that post intubation BP was low with nalbuphine compared to morphine. Even after 2 hours, SBP was low which was statistically significant and clinically acceptable. DBP was also low. 30 minutes following extubation till 180 minutes statistically significant low BP (SBP & DBP) was noted with nalbuphine which was within the clinical acceptable limits. The duration of analgesia was 437±63.87 with nalbuphine compared to 255.0±43.75 min with morphine. Side effects like sedation were more with nalbuphine for first 60 min.

CONCLUSIONS : IV nalbuphine produced clinically acceptable haemodynamic changes with significantly prolonged duration of analgesia compared to morphine.