What is "methoctramine"

Methoctramine is a polymethylene tetraamine that acts as a muscarinic antagonist. It preferently binds to the pre-synaptic receptor M2, a muscarinic acetylcholine ganglionic protein complex present basically in heart cells. In normal conditions -absence of methoctramine-, the activation of M2 receptors diminishes the speed of conduction of the sinoatrial and atrioventricular nodes thus reducing the heart rate. Thanks to its apparently high cardioselectivity, it has been studied as a potential parasymphatolitic drug, particularly against bradychardia. However, currently it’s only addressed for research purposes, since the administration to humans is still unavailable.