Cholinomimetics Flashcards
Name the 5 direct-acting cholinergic agonists.
Nicotine, muscarine, bethanechol, pilocarpine, cevimeline
Name the 6 indirect-acting, AChE inhibiting cholinomimetics
Neostigmine, physostigmine, donepezil, edrophonium, echothiophate, and soman
What is the one indirect-acting cholinomimetic that is not an AChE inhibitor? How does it work?
Pralidoxime; regenerates phosphorylated AChE
Name the 2 indirect-acting carbamic acids.
Neostigmine and physostigmine
Name the 2 indirect-acting non-ester alkaloids.
Donepezil and edrophonium
Name the 2 indirect-acting organophosphates.
Echothiophate and soman
Besides muscarine, what are the other 3 direct-acting cholinomimetics that act on muscarinic receptors?
Pilocarpine, cevimeline, and bethanechol
Which direct-acting cholinomimetic is a choline ester / carbamic acid?
Bethanechol
Which receptors do indirect cholinomimetics affect: nicotinic or muscarinic receptors?
Both, because the indirect cholinergic agonists inhibit AChE, leading to a global increase in ACh at all cholinergic receptors
What condition is pilocarpine used to treat, and how does it work?
Glaucoma - activate papillary sphincter and ciliary muscles to decrease intraocular pressure
What condition is cevimeline used to treat, and how does it work?
Dry mouth (ex. from Sjogren’s or radiation therapy) - increase salivation
Do most direct-acting cholinomimetics target nicotinic or muscarinic receptors, and what kind of effects occur as a result?
Activate muscarinic receptors, which increases parasympathetic responses such as bradycardia, vasodilation, pupillary constriction, salivation, etc.
What conditions is bethanechol used to treat, and how does it work?
Ileus and urinary retention - activate bowel and bladder smooth muscle
Do the indirect-acting cholinomimetics affect nicotine or muscarinic receptors? Do they cause sympathetic or parasympathetic effects?
Activate both muscarinic and nicotinic receptors, broadly increase ACh for both parasympathetic and sympathetic effects.
Rank the following AChE inhibitors from shortest to longest half life: neostigmine, physostigmine, edrophonium, echothiophate
Edrophonium (~10 min) - neostigmine and physostigmine (~1 hour) - echothiophate (>100 hours)
What is the major use for nicotine?
Reduce cravings in smoking cessation
What 3 cholinomimetics are used to treat glaucoma?
Pilocarpine, physostigmine, and echothiophate
Pralidoxime is a strong nucleophile that acts indirectly on Ach synapses. How is it used therapeutically?
Used to counter nerve gas or insecticide poisoning
Soman and Sarin are indirect acting organophosphate nerve gases that can lead to paralysis and death. How do they cause toxicity?
They inhibit AChE, leading to increased ACh signalling
What 2 cholinomimetics can be used to treat post-operative and neurogenic ileus as well as urinary retention? What third cholinomimetic can also treat ileus?
Bethanechol and neostigmine; edrophonium
What 2 cholinergic agonists are used to treat myasthenia gravis? Which one can be used to diagnose the disease?
Neostigmine and edrophonium; edrophonium can diagnose
What condition is donepezil used to treat? What feature of its molecular structure makes it well suited for this function?
Alzheimer’s; it is hydrophobic so can cross BBB
What 2 drugs are used to counter poisoning by soman and other organophosphates, and how does each one work?
Pralidoxime regenerates phosphorylated AChE, and atrophine inhibits the ACh-receptor
All cholinergic agonists except pralidoxime can cause SLUDGE as side effects. What does SLUDGE stand for, and what drug can counter these effects?
Salivation, Lacrimation, Urination, Defecation, GI distress, and Emesis; atropine
