Atropine sulfate
Atropine Sulfate is the sulfate salt of atropine, a naturally-occurring alkaloid isolated from the plant Atropa belladonna.  Atropine functions as a sympathetic, competitive antagonist of muscarinic cholinergic receptors, thereby abolishing the effects of parasympathetic stimulation.  This agent may induce tachycardia, inhibit secretions, and relax smooth muscles. (NCI04)