👉🏻 Cholinergic muscarinic agonists are drugs that bind to and activate muscarinic cholinergic receptors and increase the activity of the parasympathetic nervous system. They are most commonly used when it is desirable to increase smooth muscle tone, especially in the GI tract, urinary bladder, and eye. They may also be used to reduce heart rate. 👉🏻 Direct cholinergic agonists work by resisting acetylcholinesterase, thus preventing its breakdown. Drugs in this class include bethanechol, carbachol, and methacholine, and pilocarpine. 👉🏻 Indirect cholinergic agonists work by inhibiting the acetylcholinesterase enzyme preventing the degradation of acetylcholine. Drugs in this class include neostigmine, physostigmine, galantamine, donepezil, and rivastigmine.