Methylatropine is an antagonist of muscarinic acetylcholine receptors (IC50= <0.1 nM in a radioligand binding assay using isolated porcine brain membranes) and a derivative of atropine .1,2It reduces acetylcholine-induced decreases in blood pressure in rats when administered intravenously with an ED50value of 5.5 μg/kg.2Methylatropine reduces salivation, induces mydriasis, and increases heart rate in dogs.3