Through its actions on the histamine receptors, betahistine provides relief from vertigo associated with Ménière's disease. This explains the efficacy of betahistine in the treatment of vertigo. This explains the potent vasodilatory effects of betahistine in the inner ear. The increased amounts of histamine released from histaminergic nerve endings stimulates H1 receptors, thus augmenting the direct agonistic effects of betahistine on these receptors. In addition, betahistine has a powerful antagonistic effects at H3 receptors, and increases the levels of neurotransmitters released from the nerve endings. It appears to act on the precapillary sphincter in the stria vascularis of the inner ear, thus reducing the pressure in the endolymphatic space. Primarily, it has a direct stimulating (agonistic) effect on H1 receptors located on blood vessels in the inner ear. The active ingredient is a specific histamine agonist with virtually no H2-activity.īetago has two modes of action. Betago has a very strong affinity as an antagonist for histamine H3 receptors and a weak affinity as an agonist for histamine H1 receptors. The mechanism of action of betahistine is known partially.
