Tropisetron versus metoclopramide for the treatment of nausea and vomiting in the emergency department: A randomized, double-blinded, clinical trial.

Aim: We aimed to compare the relative efficacy of tropisetron and metoclopramide in treating nausea/vomiting in undifferentiated ED patients.

Methods: We undertook a randomized, double-blinded, clinical trial. Adult patients requiring treatment for nausea/vomiting were randomly assigned to either tropisetron (5 mg) or metoclopramide (10 mg), by i.v. bolus. The primary end-point was incidence of vomiting. Secondary end-points were decrease in nausea score from baseline (0-100 VAS), the requirement of 'rescue' anti-emetics, ongoing nausea over 48 h and side-effects.

Results: Fifty patients were enrolled in each group. The demographic variables, presenting complaints and nausea scores at baseline did not differ (P > 0.05). By 180 min, two (4.0%) and nine (18.0%) patients had vomited in the tropisetron and metoclopramide groups respectively (difference 14.0%, 95% CI 0.1-28.0, P= 0.05). Also, there were two and 20 episodes of vomiting respectively. Vomiting rates were 0.02 and 0.16 episodes/person-hour (difference 0.14 episodes/person-hour, 95% CI 0.07-0.21, P < 0.001) respectively. By 60 min and thereafter, the decrease in nausea score from baseline was greater (although not significantly so) in the tropisetron group. At 180 min, the decreases were 47.9 mm and 37.0 mm respectively (difference 10.9 mm, 95% CI -0.7-22.6). Five (10.0%) and 13 (26.0%) patients required a rescue anti-emetic respectively (difference 16.0%, 95% CI -0.7-32.7, P= 0.07). Of patients followed up, 13/47 (27.7%) and 20/49 (40.8%) had ongoing nausea respectively (difference 13.2%, 95% CI -7.7-34.0, P= 0.25). The tropisetron group had less akathisia.

Conclusions: Tropisetron was associated with a significantly lower vomiting rate and shows promise as an alternative anti-emetic in the ED.