Ondansetron or promethazine: Which one is better for the treatment of acute peripheral vertigo?

Background: Vertigo is a common annoying complaint needing emergent treatment. There are various treatment options for this condition with different outcomes and side effects. Objectives: Assessment and comparison of the effectiveness of Ondansetron and Promethazine in the treatment of acute peripheral vertigo. Materials and methods: This clinical trial was conducted in an academic hospital in the north of Iran in 2017. A total of 170 eligible patients were randomly allocated to groups A: received intramuscular (IM) promethazine; and B: received intravenous (IV) Ondansetron, using quadripartite blocks. The severity of vertigo, nausea, blood pressure, heart rate, side-effects, need for re-administration, and the time to become asymptomatic were assessed before the injections, 30 min after and 2 h after the injections. Results: Excellent improvement in vertigo occurred in both groups (P < 0.001), with a more significant reduction in the promethazine-treated group (P < 0.001). Nausea was reduced more significantly in the ondansetron-treated group (P < 0.05). There were more side-effects seen in the promethazine-treated when compared to the group with ondansetron treatment (P < 0.001). No significant differences were seen in the blood pressures between groups (P > 0.05). Heart rates were reduced in both groups but the changes were insignificant (P > 0.05). The ondansetron-treated group showed a greater need for re-administration of the medication (50.6% vs. 27.1%). The relief score was significantly higher in the ondansetron-treated group compared with the group received promethazine (P < 0.001). The time to become asymptomatic showed no statistically significant difference between groups (p = 0.28). Conclusion: Our results indicated that while promethazine cures peripheral vertigo more efficiently, ondansetron is more beneficial for the improvement of nausea and vomiting.