Antihistamines provide superior two hour relief of vertigo symptoms compared to benzodiazepines according to the results a meta-analysis
Antihistamines are able to provide a greater level of symptom relief, 2 hours post-dose in patients with vertigo in comparison to benzodiazepines. However, neither class of drugs seems to be better than placebo after only one week. These were the key findings from a systematic review and meta-analysis by researchers from the Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, US.
Vertigo is a symptom of vestibular dysfunction and described as a sensation of motion, most commonly rotational motion. The term dizziness is non-specific but usually refers to a sense of disorientation with vertigo being a subtype of dizziness. The sensation of dizziness is common condition and affects about 15% to 20% of adults annually and vestibular vertigo accounts for about a quarter of dizziness cases with an annual prevalence of 5%.
Pharmacological treatments for the management of vertigo are referred to as vestibular suppressants and there are a wide of drug classes such as anticholinergics (scopolamine), antihistamines (cinnarizine), benzodiazepines (clonazepam) and dopamine receptor antagonist (prochlorperazine) and histamine-1 receptor antagonists (betahistine).
In a 2017 updated clinical practice guideline, it was recommended that benzodiazepines and/or antihistamines could be used in the management of one of the most common forms of vertigo, benign paroxysmal positional vertigo. Despite this, there is an absence of comparative data for these two drug classes.
As a result, for the present study, the US team undertook a systematic review and meta-analysis to assess the efficacy of both drug classes in the management of acute vertigo due to any underlying cause.
The team searched for randomised trials which included any antihistamine or benzodiazepine compared with an active comparator, placebo or no intervention in patients with acute vertigo and which had lasted for less than 2 weeks. The primary outcome of interest was the change in a 10 or 100-point vertigo or dizziness visual analogue scale (VAS) score at 2 hours post-treatment. Secondary outcomes included change in nausea VAS score at 2 hours and resolution of vertigo after one week and a month.
Antihistamines and improvement in vertigo scores
A total of 27 trials met the inclusion criteria, of which, 17 with 1586 participants were included in the meta-analysis.
For the primary outcome, 7 trials with 802 were included. Antihistamines were associated with a 16.1-point (95% CI 7.2 – 25) greater decrease in mean VAS vertigo scores compared to benzodiazepines. However, when compared to other active treatments, antihistamines performed to a similar extent (mean difference = 7.4, 95% CI -1.12 to 15.8).
For the secondary outcomes, after one week, there was no evidence to suggest a higher likelihood of complete symptom resolution from antihistamines (relative risk, RR = 1.03, 95% CI 0.56 – 1.89) or after 4 weeks. Similarly, the improvement with benzodiazepines was no better than placebo after one or 4 weeks.
The authors concluded that there was moderately strong evidence to show that single dose antihistamines provided better relief of vertigo symptoms after 2 hours than benzodiazepines. Furthermore, the evidence did not support an association between benzodiazepine use with an improvement in acute vertigo.
Hunter BR et al. Efficacy of Benzodiazepines or Antihistamines for Patients With Acute Vertigo: A Systematic Review and Meta-analysis JAMA Neurol 2022.