Ondansetron versus Metoclopramide, both Combined with Dexamethasone, in Prevention of Emesis induced by Chemotherapy

Abstract

Background:
Prophylactic use of 5-hydroxytryptamines receptor antagonists after the first 24 h of exposure to emetic chemotherapy (to decrease the incidence of delayed phase emesis) cause an increase in the cost of treatment.
Objective:
We designed a study to evaluate the efficacy of a setron (ondansetron) in the acute and delayed phase, compared with metoclopramide, each combined with a corticosteroid.
Patients and methods:
On their course of single day emetic chemotherapy (cisplatin, carboplatin, doxorubicin, cyclophosphamide and others), one hundred patients completed this study and were divided into two groups: first group involves 52 patients received ondansetron 8 mg i.v. + dexamethasone 8 mg i.v. on day 1 as pre-chemotherapy, followed for 5 days by ondansetron 8 mg tid orally + dexamethasone 4 mg bid orally, second group involves 48 patients received metoclopramide 10 mg i.v. + dexamethasone 8 mg i.v. on day 1 as pre-chemotherapy, followed for 5 days by metoclopramide 10 mg tid orally + dexamethasone 4 mg bid_orally. Patients evaluated the results using a diary card. Results:
Control of acute emesis in both arms was similar (86% for ondansetron gr. and 85% for metoclopramide gr.). These well controlled patients also had control of delayed emesis in 81% of ondansetron and 84% of metoclopramide treated cases. Patients experiencing acute emesis had poor control in the delayed phase. Incidence of toxicity was variable between the two arms.
Conclusion:
Administration of i.v. ondansetron with dexamethasone achieves an extremely high control of acute emesis. Our data suggest that routine prescription of setrons for delayed phase control is not advisable as it increases the cost without any benefit over metoclopramide for the majority of patients. Delayed emesis in the rare patients with acute phase emesis remains an unsolved problem.