cholinergic drugs Flashcards
cholinergic drugs
-drugs that stim the parasympathetic nervous system
-aka parasympathomimetics
- mimic acetylcholine
2 types of cholinergic receptors
- nicotinic receptors
- muscarinic receptors
nicotinic receptors
in the ganglia of both systems
can be stimulated by nicotine
muscarinic receptors
- postsynaptically in effector organs of parasympathetic system (smooth, cardiac muscle, glands)
cholinergic drug MOA
direct acting (bind to receptors activating them)
indirect-acting (cholinesterase inhibitors which is the enzyme that breaks down ACh)
indirect acting reversible
binds to cholinesterase for short period of time
indirect acting irreversible
- binds for long period of time
- forms a covalent bond
- body must make new cholinesterase to break these bonds
drug effects
- rest and digest
- stim intestines and bladder (Increased gastric secretions, GI motility, urinary freq)
- stim pupils (constriction and reduce intraocular pressure)
- increased salivation and sweating
cardiovascular drug effects
decreased HR and vasodilation
resp drug effects
bronchial constriction, narrowed airways
at recommended doses cholinergic primarily affect
muscarinic receptors
at high doses cholinergics stimulate
nicotinic receptors
(can cause undesirable effects)
direct acting indications
reduce intraocular pressure and useful for glaucoma and intraocular surgery
eye drop direct acting ex
pilocarpine
direct acting bethanechol indication
- increases GI activity
- PO or subcut
direct acting succinylcholine
- neuromuscular blocker in general anesthesia
- IV
indirect acting indications
- increases ACh concentrations to stim effector cells
- causes skeletal muscle contractions
- diagnosis and treatment of myasthenia gravis
- reverse neuromuscular blocking drugs
- reverse anticholinergic poisoning