Additive anti-emetic efficacy of prophylactic ondansetron with droperidol in out-patient gynecological laparoscopy.

PURPOSE

To determine the efficacy of ondansetron and droperidol, alone and in combination, administered for prophylaxis of postoperative nausea and vomiting (PONV) in women undergoing general anesthesia for outpatient gynecological laparoscopy.

METHODS

Following Institutional Ethics Board approval and patient consent, 160 female out- patients scheduled for laparoscopy were randomly allotted in a double-blind fashion to receive: i) saline (placebo), ii) 4 mg ondansetron, iii) 1.25 mg droperidol, or iv) 4 mg ondansetron and 1.25 mg droperidol combination intravenously on induction. Following a standardized general anesthesia, patients were interviewed and assessed for PONV at various times.

RESULTS

During the first 24 hr after surgery, the incidence of PONV in the placebo group was 71%. This was reduced to 61% with droperidol alone (P = 0.334), to 46% with ondansetron alone (P = 0.027), and to 23% with the combination group (P<0.001). A statistically significant difference was observed between combination and droperidol (P<0.001) and between combination and ondansetron (P = 0.036). There were fewer requests for rescue medication from the combination group (7.7%) than from the ondansetron and placebo groups.

CONCLUSION

The results of this study suggest that the combination of 4 mg ondansetron and 1.25 mg droperidol is more efficacious as a prophylactic anti-emetic than either agent alone during the 24 hr post-surgery. This additive effect may be due to the different mechanisms of action of ondansetron and droperidol.