Antiemetic effect of ondansetron versus metoclopramide in nauseous isolated head trauma patients: a double-blind randomized clinical trial

Objective: As nausea is one of the most common annoying symptoms in isolated head trauma (IHT) and needs timely management to prevent further adverse outcomes, this study was performed to compare ondansetron and metoclopramide as therapeutic agents in nauseous IHT. Methods: This study was a double-blind clinical trial. Participants were patients visiting the ED with the chief complaint of nauseous IHT event. Group A received 10mg/2ml of metoclopramide and group B 4mg/2ml of ondansetron through slow intravenous (IV) injection. The primary outcome was the severity of nausea 20 minutes after the intervention based on the visual analogue scale (VAS) score. Results: A total of 130 patients participated in the study (65 in each group). The mean age was 30.5 +/- 20.5 years, and 73.1% of the participants were male. The decrease in the mean nausea severity scores was statistically significant in both group A (78.3 +/- 9.7 before vs. 29.8 +/- 16.8 mm after the intervention; P < 0.001) and group B (78.5 +/- 11.1 vs. 27.8 +/- 13.9 mm; P < 0.001). There was no significant difference between the mean nausea severity scores of groups A and B before the intervention (P = 0.93) or after it (P = 0.65). The decrease in the severity score of nausea was 48.5 mm in group A and 50 6 mm in group B, with no significant difference between the two groups (P = 0.63). Conclusion: Both Ondansetron and metoclopramide significantly reduced the severity of nausea in patients with mild IHT visiting ED but no treatment arm was superior. Both drugs showed good safety profiles.