Comparison of The Effectiveness of Ondansetron and Metoclopramide in Nausea and Vomiting: Literature Review

Abstract

Nausea and vomiting are common clinical manifestations across various medical conditions, including renal colic, acute gastroenteritis, postoperative recovery, and inpatient care, thereby requiring the use of effective antiemetic agents. Ondansetron, a selective 5-HT₃ receptor antagonist, and metoclopramide, a dopamine D₂ antagonist with additional prokinetic activity, are among the most widely used antiemetics, yet their effectiveness varies depending on clinical indications. This literature review aimed to compare the effectiveness and safety profiles of ondansetron and metoclopramide by synthesizing evidence from five eligible studies selected through a systematic PRISMA-based screening of articles retrieved from Google Scholar, PubMed, and ScienceDirect using predefined keywords. The studies demonstrated consistent findings that ondansetron is more effective in reducing or stopping vomiting across several conditions, including renal colic, acute gastroenteritis in children, and postoperative nausea and vomiting (PONV), with superior symptom control observed within the first hours after administration. Meanwhile, metoclopramide showed clinically relevant benefits in adult inpatients with mixed etiologies of nausea, particularly in cases associated with delayed gastric emptying, although its overall effectiveness was reported to be slightly lower than that of ondansetron. In terms of safety, ondansetron was associated mainly with headache and constipation, whereas metoclopramide exhibited risks of extrapyramidal symptoms despite low incidence in the included studies. Overall, the findings indicate that ondansetron provides more consistent and rapid control of vomiting, while metoclopramide remains applicable in selected cases requiring prokinetic effects. These results emphasize the importance of considering individual patient profiles, clinical indications, and potential adverse effects when selecting antiemetics and highlight the need for further standardized comparative studies to strengthen the evidence base for clinical decision-making.