webmedi.blogspot.com

 BETAHISTINE BRAND NAME:- VERTIN 8mg  tab . BETAHISTINE is an orally active,somewhat H1 selective Histamine analogue, which is used to control vertigo in patients of Meniere's disease: possibly acts by causing vasodilation in the internal ear. It is contraindicated in asthmatics and ulcer patients. PHARMACODYNAMIC:- Betahistine is a strong antagonist of the histamine H3 receptor and a weak agonist of the histamine H1 receptor.[1] Betahistine has two mechanisms of action. Primarily, it is a weak agonist on the H1 receptors located on blood vessels in the inner ear. This gives rise to local vasodilation and increased permeability, which helps to reverse the underlying problem of endolymphatic hydrops. More importantly, betahistine has a powerful antagonistic effects at H3 receptors, thereby increasing the levels of neurotransmitters histamine, acetylcholine, norepinephrine, serotonin, and GABA released from the nerve endings. The increased amounts of histamine released from hist...