Comparison of the effect of Promethazine, Ondansetron, and Diazepam on Peripheral Vertigo; A Randomized Clinical Trial Study

Vertigo is one of the common causes of the admission of patients to the emergency department. The aim of this study was to compare the effects of promethazine, ondansetron, and diazepam in the treatment and management of vertigo.

This was a randomized clinical trial study conducted in Alzahra and Kashani hospitals, Isfahan, Iran, in 2019. 105 patients with peripheral vertigo were randomly divided into three groups of 35, which received 25 mg of promethazine (intramuscularly), 4 mg of ondansetron (intravenously), and 5 mg of diazepam (intravenously), respectively. The intensity of vertigo was measured before and after injection, and was compared between the three groups.

The mean severity of vertigo before and after treatment was 6.98 ± 1.26 and 3.43 ± 2.29 in promethazine group, 6.97 ± 1.01 and 2.14 ± 1.15 in ondansetron group, and 6.4 ± 1.26 and 2.97 ± 2.09 in diazepam group, respectively (P < 0.001). The percentage of reduction in dizziness severity was 49.4 ± 33.5, 67.57 ± 24.4, and 54.0 ± 32.0 percent in promethazine, ondansetron, and diazepam groups, respectively, and the reduction in the severity of dizziness was significantly different between the three groups (P = 0.035).

All promethazine, ondansetron, and diazepam drugs are effective in improving vertigo symptoms, but ondansetron is more effective than the two other drugs.