Antimuscarinic actions of antihistamines on the heart.

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Liu H, Zheng Q, Farley JM

Antimuscarinic actions of antihistamines on the heart.

J Biomed Sci. 2006 May;13(3):395-401.

PubMed ID

16453179 [ View in PubMed

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Abstract

Antimuscarinic side-effects, which include dry mouth, tachycardia, thickening of mucus possibly sedation, of the antihistamines limited the usefulness of these drugs. The advent of newer agents has reduced the sedative effect of the antihistamine. The data presented here show that one of the newest antihistamines, desloratadine, and a first generation drug, diphenhydramine, are both competitive inhibitors of muscarinic receptor mediated slowing of the heart as measured using a Langendorff preparation. Both agents have apparent sub-micromolar affinities for the muscarinic receptor. Two other agents, cetirizine and fexofenadine, do not interact with muscarinic receptors in the heart at the concentrations used in this study. Structural similarities of the drugs suggest that substitution of a group with a high dipole moment or charge on the side chain nitrogen decreases the binding with muscarinic receptors. We conclude that of the compounds tested fexofenadine and cetirizine have little or no interaction with muscarinic receptors.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Diphenhydramine	Muscarinic acetylcholine receptor M2	Protein	Humans	Unknown	Antagonist	Details