Introduction
Azatadine is a pharmacological agent celebrated for its role as an antihistamine, contributing to the management of allergic conditions. As a selective antagonist at H1 histamine receptors, azatadine efficiently mitigates the effects of histamine, offering relief from common allergic symptoms such as itching, sneezing, and a runny nose. Widely employed in the treatment of allergic rhinitis and conjunctivitis, azatadine serves as a valuable tool in alleviating discomfort associated with hay fever and other allergic reactions. Available in oral formulations, including tablets and syrups, its administration provides convenience in addressing allergy-related manifestations.
Structure
Synthesis
Route I. From: 2-Chloro-3-phenethylpyridine
Route II. From: Phenylacetonitrile
Mechanism of action
Azatadine exerts its pharmacological effects through its action as a selective antagonist at H1 histamine receptors. The primary mechanism of action includes:
- Antagonism at H1 Histamine Receptors:
- Azatadine competitively binds to and blocks the activity of H1 histamine receptors.
- By inhibiting histamine from binding to these receptors, azatadine mitigates the effects of histamine, thereby alleviating symptoms associated with allergic reactions.
- Reduction in Cholinergic Effects:
- Azatadine may also have some anticholinergic effects, contributing to its use in conditions where a decrease in acetylcholine activity is desired.
- This reduction in cholinergic effects can be beneficial in certain clinical situations.
Properties and uses:
Azatadine is a potent, long-acting antihistaminic with ant-serotonin activity. In early testing, azatadine exhibited more than three times the potency of chlorpheniramine in the isolated guinea pig ileum screening and more than seven times the oral potency of chlorpheniramine in the protection of guinea pig against a double lethal dose of intravenously administered histamine.