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
