Question

Antihistamine drugs are antagonists for which receptor?

(a) H1 receptor antagonist

(b) H2 receptor antagonist

(c) H3 receptor antagonist

(d) H4 receptor antagonist

I have been asked this question at a job interview.

Question is from Drug Concentration and Pharmacologic Response in division Applications of Pharmacokinetic Principles, Diuretics, Drug Concentration and Pharmacologic Response of Drug Biotechnology

Answer 1

Correct choice is (a) H1 receptor antagonist

For explanation: A drug that reduces or eliminates the effects mediated by the chemical histamine. True antihistamines produce a therapeutic effect which will be mediated by negative modulation of histamine receptors. The term antihistamine only refers to H1 receptor antagonists. Antihistamines compete with histamine for binding sites at the receptors. Antihistamine cannot remove the histamine if it is already bound.