Betahistine in the treatment of vertiginous syndromes: a meta-analysis.

Vertigo is a very frequent disorder, associated with highly disabling symptomatology. Since the aetiology cannot always be easily identified, treatment is often addressed to the symptoms. Betahistine, a drug characterized by a multi-factorial mode of action of the modulatory type, has been widely employed in the management of various vertiginous syndromes. Its use in Italy is, currently, authorized to treat the vertiginous symptoms related to Ménière's disease. A meta-analysis has, therefore, been carried out to assess, the efficacy of betahistine in the treatment of other vertiginous syndromes, such as positional paroxysmal vertigo (cupulo-canalolithiasis) and vertigo secondary to arterial deficiency of the vertebrobasilar area, regardless of the specific cause. A review has been made of the literature concerning clinical trials performed with betahistine versus placebo in a randomised double-blind, parallel-group or cross-over design. Only studies evaluating betahistine in patients with vertiginous symptomatology not related to Ménière's disease were selected. Of the 104 publications, obtained from an analysis of "Medline", "EMBASE" and "CINAHL" databases, 7 clinical studies, which met the selection criteria, for a total of 367 patients, were extrapolated and analysed. The meta-analysis was conducted using the "Cochrane Collaboration's Review Manager" software in all the case series and in the sub-groups identified by the experimental design (parallel or crossover design), range of dosages (32-48 mg/day) and range of treatment duration (from 3 weeks to 4 months). The various parameters used to evaluate efficacy, adopted in the trials, and taken into account in the metaanalysis, as overall judgement of the patient or physician, number of vertiginous episodes and their duration, were classified according to the binary classification of "improved" and "not improved". The results of the meta-analysis confirm the therapeutic benefit of betahistine versus placebo. In particular, the investigation carried out on the overall sample shows an odds ratio of 3.52 (95% confidence interval 2.40-5.18) and a relative risk of 1.78 (95% confidence interval 1.48-2.13), while the analysis of the sub-groups denotes a maximum efficacy after doses of 32 to 36 mg and with a period of treatment of 3-8 weeks. The present meta-analysis confirms the benefit of drug treatment with betahistine for the vertiginous symptomatology related to cupulo-canalolithiasis and vertebro-basilar arterial insufficiency.