betahistine

Betahistine is a prescription medication used to treat vertigo, particularly that associated with Ménière's disease and other balance disorders. It is commonly marketed under brand names such as Serc in several countries and is typically taken orally in divided doses.

The mechanism of action of betahistine is not fully understood. It acts as a histamine H3 receptor antagonist and has weak histamine H1 receptor agonist activity. By antagonizing H3 receptors, it is thought to increase histamine release and turnover in the brain, which may improve inner ear microcirculation and reduce endolymphatic hydrops, contributing to a reduction in vertigo symptoms. The exact relationship between histaminergic activity and clinical effects remains a subject of research.

In clinical use, betahistine is prescribed to reduce the frequency and severity of vertigo attacks and to improve balance in Ménière's disease. Evidence from randomized trials is mixed, with some studies reporting modest benefit and others showing limited or inconclusive efficacy. Regulatory status varies by country; it is not approved by the U.S. Food and Drug Administration and may not be available in all markets.

Common adverse effects are generally mild and include headaches, gastrointestinal upset, and allergic reactions in rare cases. Like other histaminergic agents, caution is advised in patients with peptic ulcers or gastritis, and data on use during pregnancy and lactation are limited, requiring medical judgment.

Pharmacokinetics of betahistine indicate rapid oral absorption with metabolism occurring in the liver and elimination primarily via the urine. Dosing is individualized and varies by country-approved regimens and formulations. Patients should follow local prescribing guidance and consult their physician for specific dosing information.