Autonomics: Acetylcholinesterase Inhibitors Flashcards
What long-term drug is used to treat myasthenia gravis?
Pyridostigmine
What three acetylcholinesterase inhibitors can treat Alzheimer’s?
Galantamine (think of the gala of old people) Rivastigmine (“reverse the stigma!”) Donepazil (“done with the puzzle!”)
Pralidoxime binds to organophosphate-bound acetylcholinesterase, which helps treat organophosphate poisoning, but it only works ___________.
quickly after poisoning (think of the old man spraying poison on the dumpster)
Explain how physostigmine can correct atropine overdose.
Atropine blocks muscarinic receptors, leading to parasympatholytic symptoms (“mad as a hatter, blind as a bat, hot as a hare”). Physostigmine can generate more acetylcholine, thus outcompeting atropine for muscarinic sites.
What’s one of the main distinctions between direct-acting muscarinic agonists and indirect-acting cholinesterase inhibitors?
The inhibitors stimulate the nicotinic acetylcholine receptors, too.
What is the dumbbells mnemonic for parasympathetic symptoms?
All things that come from muscarinic activation: DiarrheaUrinationMiosisBradycardiaBronchospasmLacrimationSalivation
What is the clinical role of edrophonium?
Because it is short-acting, it is not useful for treating MG. However, some patients with MG might present with worsening weakness that could be due to insufficient acetylcholine or too much acetylcholine (called cholinergic crisis – results from refractory synapses). Giving edrophonium can differentiate the two.
Explain how succinylcholine is a depolarizing agent.
It mimics acetylcholine and depolarizes the membrane, but it does not get degraded as easily – preventing further action potentials.
What drug can correct organophosphate poisoning?
Pralidoxime (“Put a LID on the tOXic pesticide”) for the peripheral side effects and atropine
