NCIt definition : The hydrochloride salt form of guanidine, a strong basic compound with parasympathomimetic
activity. Guanidine hydrochloride enhances the release of acetylcholine following
a nerve impulse and potentiates acetylcholine actions on muscarinic and nicotinic
receptors. It also appears to slow the rates of depolarization and repolarization
of muscle cell membranes. (NCI05);