Effect of ondansetron pretreatment on pain after rocuronium and propofol injection: a randomised, double-blind controlled comparison with lidocaine

In a randomised, controlled, double-blinded trial to study the effect of ondansetron pretreatment on the pain produced after intravenous injection of rocuronium and propofol in comparison with lidocaine, 60 patients were randomly assigned to one of three groups. Group 1 received 5 ml of intravenous 0.9% sodium chloride solution pretreatment, group 2 received ondansetron 4 mg (2 mg.ml-1 solution) diluted into a 5-ml solution, and group 3 received 50 mg lidocaine (5 ml 1% solution); this was followed 1 min later by rocuronium and propofol. Pain was reduced significantly in the ondansetron and lidocaine groups (p < 0.0001) compared with placebo, and significantly better with lidocaine than with ondansetron (p = 0.02). We conclude that ondansetron is effective in relieving the pain of rocuronium but is not as effective as lidocaine.