Intravenous promethazine versus lorazepam for the treatment of peripheral vertigo in the emergency department: A double blind, randomized clinical trial of efficacy and safety

Abstract

Vertigo imposes considerable health restrictions with significant impact on the patient's quality of life. The most effective antivertigo agent is undetermined thus far. This study was performed to assess whether promethazine has superior vertigo reduction compared with lorazepam in ED patients. In this randomized, double-blind, parallel group trial 184 patients were assigned (1:1 ratio) to receive either promethazine, 25 mg intravenously, or lorazepam, 2 mg intravenously. Primary endpoint was mean change in vertigo intensity at 2 hours measured using visual analog scale (VAS). Secondary endpoints were mean change in nausea score, need for second dose of study medications, and adverse events (AEs). Promethazine was associated with significantly more reduction (46.5 mm) in vertigo than lorazepam (25.7 mm, p< 0.001). Mean change in nausea score 2 hours after drug injection on the VAS was 28.7 mm for promethazine and 22.8 for lorazepam (p=0.002). The most frequently reported AEs were lethargy (14.1% in lorazepam group, 4.3% in promethazine group, p=0.013) and drowsiness (10.8% for promethazine, 2.1% for lorazepam, p=0.017). Our study demonstrated the evidence that promethazine is superior to lorazepam in management of peripheral vertigo and vertigo-related nausea in ED adults.