Pyrilamine maleate, also known as pyrilamine maleate, is a first generation histamine H
1 receptor antagonist. Pyrilamine 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. Pyrilamine permeates the blood-brain barrier causing drowsiness. Pyrilamine also has anticholinergic properties. For reference, we also have related first generation histamine H
1 receptor antagonists, such as pheniramine maleate [
P2271], chlorpheniramine maleate [
C0873] and bromopheniramine maleate [
B5167]. (The product is for research purpose only.)