Natural or synthetic Antimuscarinic Agents inhibit acetylcholine neurotransmitter action at muscarinic receptors. Antimuscarinic drugs are used as antiarrhythmic, antiparkinson, antiasthmatic, and antispasmodic agents, as well as antidote of the natural mushroom alkaloid muscarine (Amanita muscaria) or to prevent parasympathetic stimulation at neuroeffector junctions. (NCI04)