Autonomic - Acetylcholinesterase Inhibitors (Indirect Cholinonmimetics) Flashcards
How do acetycholinesterase inhibitors (indirect cholinomimetics) raise acetylcholine levels?
Prevent aetycholinesterase from degrading acetylcholine to raise or increase length of time of acetylcholine.
What is the suffix of most acetycholinesterase inhibitors?
“-stigmine” (STIGMA graffiti)
Where does acetylcholinesterase inhibit acetylcholine?
At the neuromuscular junctions (plug box). Increase activity of nicotinic acetylcholine receptors.
Acetycholinesterase inhibitors increases or decreases strength of contraction?
Increases by increasing activity of nictoinc Ach receptors
What are the symptoms of myasthenia Gravis? How does it cause these symptoms?
Progressive muscle weakness, ptosis, diplopia by creating antibodies against nicotinic Ach receptors at motor end plates, inactivating them.
What does pyridostigmine treat? How?
Pyridostigmine (girl wearing community pride jacket) treats myasthenia gravis by increasing Ach to outcompete MG antibodies.
What does neostigmine treat?
Neostigmine (Neon STIGMA sign) also treats myasthenia gravis. But it is not as common
What does edrophonium treat?
Transiently reverses symptoms of myasthenia gravis.
What are the quaternary amines. What is special about them?
Pyridostigmine, neostigmine, edrophonium. They do not penetrate into the CNS
How is edrophonium used int he Tensilon test?
Because it only relieves muscle weakness for 5-15 minutes it is used as a diagnostic tool. If it is positive tensilon test then the patient is being under treated and needs more medication (phonebooth with person talking on phone and tense phone line). The negative tensilon test means that it failed to reverse muscle weakness and patient needs to reduce amount of medication taking (phone boooth with cut off phone line).
What are non-depolarizing neuromuscular blocking agents? What do they do?
Tubucurarine, pancuronium, cisatracurium (“curare” crayons). Inhibit nicotinic Ach receptors at NMJ endplate.
What drug reverses the non-depolarizing neuromuscular blockade?
Neostigmine (Neon sign store owner kicking out Curare crayon kid).
What is a depolarizing neuromuscular blocking agent? What does it do to do?
Succinylcholine (“SUCKS” graffiti). Overstimulates NMJ causing muscles to remain depolarized and unable to respond to stimulus.
Is the initial Phase-1 of the depolarizing blockade of succinylcholine reversible or irreversible? How does acetycholinesterase inhibitors affect this?
Irreversible. It potentiates the blockade.
What type of drug is succinylcholine?
Nictonic Ach receptor agonist
What can acetylcholinesterase inhibitors be used to treat other than myasthenia gravis?
Urinary retention (bladder hose)
Which drug is an acetycholinesterase inhibitors with central effects?
Physostigmine (PHYS Ed center)
What does physostigmine reverse?
Atropine overdose
Where is atropine naturally occurring?
Belladonna flowers and jimson weed
What are the symptoms of acetycholinesterase inhibitor toxicity (side effects of acetycholinesterase inhibitors)?
DUMBBELS (diarrhea, urination, miosis, bronchospasm, bradycardia, lacrimation, salivation, sweating)
(Dumbbellls in PHYS ED gym)
What other side effect does acetycholinesterase inhibitors cause?
Flaccid paralysis (NMJ nictonic Ach receptor over-activation)
(Weak nicotine kid in PHYS ED building)
What are types of acetycholinesterase inhibitors?
Insecticides (organophosphates): parathion, malthion, echotiophate
(Thiol spray)
What are organophosphates a major cause of?
Acute cholinergic toxicity
What reverses organophosphate toxicity?
Pralidoxime (Closing lid of of garbage dump on toxicity)
What drug reverses cholinergic toxicity including flaccid paralysis? How?
Pralidoxime. Regenerates acetycholinesterase at muscarinic and nicotinic receptors (new toxic waste dumpsters)
What reverses both peripheral and central muscarinic toxicity from organophosphate poisoning?
Atropine
What reverses only peripheral muscarinic toxicity?
Pralidoxime
What does aging of organophosphate lead to?
Irreversible binding (old pest control man that is spraying a hole in the garbage can cuasing acety cola bottles to spill out)
When is pralidoxime ineffective?
Once aging of organophosphate cholinesterase complex has occurred
What is used to treat Alzheimer’s disease?
Gala time (Alzheimer’s Gala), Rivastigmine (Reverse the Stigma), Donepezil (Done with the puzzle)
T/F: Galantine, Rivastigmine, and Donepezil do not penetrate the CNS
F, they do.
