Brompheniramine maleate is a first generation histamine H
1 receptor antagonist. Brompheniramine binds to a G protein-coupled form of the receptor and promotes a G protein-coupled inactive state of the H
1 receptor that interferes with the Gq/11-mediated signaling. Brompheniramine permeates the blood-brain barrier causing drowsiness. Brompheniramine also has anticholinergic properties. For reference, we also have related first generation histamine H
1 receptor antagonists, such as pheniramine maleate [
P2271] (H instead of Br), chlorpheniramine maleate [
C0873] (Cl instead of Br) and pyrilamine maleate [
P2369]. (The product is for research purpose only.)