PHRM 311 Lecture Notes - Domperidone, Muscarinic Antagonist, Metoclopramide
Document Summary
List the receptors involved in nausea & vomiting. Muscarinic receptors are gpcrs gq/11 (m1, m3, m5) or gi/go (m2, m4) Atropine, l-hyoscine (natural alkaloids) non-selective muscarinic antagonists. L-hyoscine crosses bbb much more readily than atropine, centrally-acting antiemesis, drowsiness. Point out structural features & differentiate classes of antihistamines that contribute to their activity against n/v. Expressed in the smooth muscle of lungs, gut, and uterus, as well as endothelium, cns, and nerve endings. Gpcr coupled to gq/11 stimulates phospholipase c. In cerebral cortex, activation leads to inhibition of cell membrane potassium channels, bringing the cell closer to its firing threshold (i. e. excitatory) Antagonism/inverse agonism reverses neuronal excitation and causes drowsiness (antiemetics are 1st generation antihistamines) Dimenhydrinate 8-chlorotheophillinate salt of diphenhydramine (targets the h1 receptor as an inverse agonist) 8-chlorotheophilline acts as a stimulant by inhibiting. Ability to cross bbb linked to lipophilicity, low mw, pka, lack of recognition by.
