Physostigmine
Physostigmine is a parasympathomimetic, specifically, a reversible cholinesterase inhibitor. By interfering with the metabolism of acetylcholine, physostigmine inderectly stimulates both nicotinic and muscarinic receptors. Physostigmine is used to treat glaucoma. Because it crosses the blood-brain barrier, it is also used to treat the central nervous system effects of atropine overdose.