Cholinergic Drugs Flashcards
Botulinum Toxin
Action: metalloprotease; cleaves a protein in cholinergic nerve terminal and blocks ACh release.
Uses: treatment of muscle spasms, strabismus, anal fissure, migraines, overactive bladder, & excessive sweating; smooth facial wrinkles.
Toxicity: paralysis may spread beyond site of injection; difficulties in swallowing and breathing; urinary retention; facial paralysis; dysphagia.
Other: duration of action can last for many weeks; “Real” generic names: onabotulinumtoxinA, abobotulinumtoxinA, rimabotulinumtoxinB.
Donepezil (“Donut-Puzzle”)
Class: acetylcholinesterase inhibitor (“a-seagull-cola-nest with inhibiting chains”).
Indication: Alzheimer’s disease (“old-timer clock being lead home by puzzle pieces”, slows decline in cognition and functional independence).
Side effects: nausua/vomitting (“seagull vomitting”); dizziness (“dizzy seagull”); insomnia; bradycardia.
Ecothiophate
Action: organophosphate (irreversible) acetylcholinesterase inhibitor.
Uses: opthalmic administration; produce miosis to increase drainage of aqueous humor in glaucoma.
Toxicity: lacrimation; blurred vision.
Neostigmine (“Neon-Stick-Man”)
Action: carbamate (covalent reversible) acetylcholinesterase inhibitor (“a-seagull-cola-nest with inhibiting chains”).
Uses: reversal of neuromuscular blockade (“neon-stick-man reversing car through blocks”); urinary retention; myasthenia gravis (“neon-stick-man punching mice-in-graves”).
Toxicity (“DUMBBELSS gym”): lacrimation; diarrhea; urinary urgency; miosis; fasciculations; respiratory depression; bradycardia; bronchoconstriction; cholinergic crisis.
Other: 4° ammonium, does not enter CNS after systemic administration.
Physostigmine (“Fly-Stick-Man”)
Action: carbamate (covalent reversible) acetylcholinesterase inhibitor (“a-seagull-cola-nest with inhibiting chains”); crosses BBB (“fly-stick-man carrying cola-mime over BBB wall”).
Uses: reversal of neuromuscular blockade; treatment of muscarinic antagonist toxicity (@-trooper with overdose-pill-bottle”); topical for acute glaucoma relief (“glock-eye”).
Toxicity (“DUMBBELSS”): lacrimation; diarrhea; urinary urgency; miosis; fasciculations; respiratory depression; bradycardia; bronchoconstriction.
Edrophonium (“Edward-Phone-Thumb”)
Action: non-covalent reversible acetylcholinesterase inhibitor (“a-seagull-cola-nest with inhibiting chains”).
Uses: diagnosis of myasthenia gravis (“mice-in-graves with DX screen”); titration of cholinesterase dose in myasthenia.
Toxicity (“DUMBBELSS”): cholinergic crisis; lacrimation; diarrhea; urinary urgency; miosis; fasciculations; respiratory depression; bradycardia; bronchoconstriction.
Other: rapidly eliminated by kidneys; very short duration of action.
Pralidoxine (“Piranha-Duck”)
Action: reactivation of acetylcholinesterase after organophosphate toxicity (“piranha-duck biting at a-seagull-cola-nest with inhibiting chains”).
Uses: organophsphate poisoning.
Toxicity: blurred vision; tachycardia; hypertension.
Other: usually given with atropine (“@-trooper shooting at a-seagull-cola-nest with inhibiting chains”).
Acetylcholine
Action: agonist at nicotinic and muscarinic receptors.
Uses: miosis for cataract surgery.
Toxicity: bradycardia; hypotension; respiratory distress.
Succinylcholine (“Sucker-In-Cola”)
Action: depolarizing (“D-polar-bear”) neuromuscular blocker (“nerve-muscle block roller coaster”); partial agonist at nicotinic acetylcholine receptor (“dragonist drinking a-seagull-cola receptor while dumping sucker-cola on a motor-cigarette-receptor”); paralysis due to desensitization of nAChR.
Uses: muscle relaxant (“paralyzed guy in wheelchair”).
Toxicity: respiratory paralysis; malignant hyperthermia.
Other: hydrolyzed by plasma cholinesterse; short-acting; phase 1 = cells kept in depolarized state, cannot be reversed (“man locked in wheelchair during phase 1-wand of roller coaster”); phase 2 = cells are repolarizing, can be reversed by neostigmine (“neon-stick-man pulling man out of wheelchair during phase-tutu of roller coaster”).
Mivacurium
Action: Competitive antagonist at neuromuscular nicotinic receptors.
Uses: Muscle relaxant.
Toxicity: Respiratory paralysis.
Tubocurarine chloride (d-tubocurarine)
Action: Competitive antagonist at neuromuscular nicotinic receptors.
Uses: Muscle relaxant.
Toxicity: Respiration paralysis.
Other: Rarely used.
Dantrolene
Action: Blocks calcium release from SER (acts at ryanodine receptor).
Uses: Succinylcholine-induced malignant hyperthermia.
Toxicity: Hepatotoxicity.
Nicotine
Action: Agonist at ganglionic (nicotinic) and muscle nicotinic receptors.
Uses: Cessation of smoking.
Toxicity: Hypertension, tachycardia; diarrhea.
Bethanecol
Action: Muscarinic agonist.
Uses: Increase motility in GI and urinary tracts.
Toxicity: Bronchoconstriction; hypotension; diarrhea; urinary urgency.
Other: Caution in patients with asthma.
Carbamylcholine (carbachol)
Action: Agonist at nicotinic and muscarinic receptors.
Uses: Miosis for surgury; decrease intraoccular pressure.
Toxicity: None.
Other: Caution in patients with asthma.
