Diazepam and Meclizine Are Equally Effective in the Treatment of Vertigo: An Emergency Department Randomized Double-Blind Placebo-Controlled Trial

J Emerg Med. 2017 Jan;52(1):23-27. doi: 10.1016/j.jemermed.2016.09.016. Epub 2016 Oct 24.


Background: Vertigo is a debilitating disease that is commonly encountered in the emergency department (ED). Diazepam and meclizine are oral medications that are commonly used to alleviate symptoms.

Objectives: We sought to determine whether meclizine or diazepam is superior in the treatment of patients with peripheral vertigo in the ED.

Methods: We performed a double-blind clinical trial at a suburban, teaching ED. We randomized a convenience sample of adult patients with acute peripheral vertigo (APV) to diazepam 5 mg or meclizine 25 mg orally. Demographic and historical features were recorded on a standardized data form. Patients recorded their initial level (t0) of vertigo on a 100-mm visual analog scale (VAS) and after 30 min (t30) and 60 min (t60). The primary outcome parameter was the mean change in VAS score from t0 to t60. Differences between groups and 95% confidence intervals were calculated. Our a priori power calculation estimated that a sample size of 20 patients in each group was required to have an 80% power to detect a difference of 20 mm between treatment groups.

Results: There were 20 patients in the diazepam group and 20 in the meclizine group. The two groups were similar with respect to patient demographics and presenting signs and symptoms. At t60, the mean improvements in the diazepam and meclizine groups were 36 and 40, respectively (difference -4; 95% confidence interval -20 to 12; p = 0.60).

Conclusion: We found no difference between oral diazepam and oral meclizine for the treatment of ED patients with acute peripheral vertigo.

Keywords: benign paroxysmal positional vertigo; diazepam; meclizine; vertigo.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Diazepam / pharmacology*
  • Diazepam / therapeutic use
  • Double-Blind Method
  • Emergency Service, Hospital / organization & administration
  • Emergency Service, Hospital / statistics & numerical data
  • Female
  • Humans
  • Male
  • Meclizine / pharmacology*
  • Meclizine / therapeutic use
  • Middle Aged
  • Prospective Studies
  • Treatment Outcome*
  • Vertigo / drug therapy*


  • Meclizine
  • Diazepam