Cholinergic Agonists Flashcards
other name for sympathetic divisioin
adrenergic - fight or flight
neurotransmitter - preganglionic
acetylcholine
neurotransmitter - end organs (sympathetic)
norepinephrine
receptors that receive norepinephrine (sympathetic)
alpha and beta
other name for parasympathetic division
cholinergic - rest and digest
what stops (metabolizes) relationship with norepinephrine
MAO and COMT
neurotransmitter (parasympathetic)
acetylcholine
receptors for acetylcholine (parasympathetic)
nicotinic or muscarinic
what stops (catabolizes) relationship (parasympathetic)
acetylcholinesterase or pseudocholinesterase
if a medication is an agonist what does it do
makes it more - promote cholinergic response
if medication is an antagonist what does it do
decreases it - stop it
cholinergic agonist aka
parasympathoneumetic - mimics parasympathetic nervous system
cholinergic agonists (parasympathoneumetics) do this
increase the action of acetycholine - promote rest and digest
direct acting agonist acts just like
acetylcholine - protype is bethanecol
**what does bethanecol do
**used for urinary retention
one class of drugs direct acting on nicotinic
nicotine
indirect acting cholinergic agonists - acts on nicotinic and muscarinic
binding to acetylcholinesterase - promote action of acetylcholine - binds for a short time - reversible drugs
what disease process would indirect acting cholinergic agonists help
myasthenia gravis - immune system is destroying receptors for acetylcholine
prototype for indirect acting cholinergic agonists
neostigmine - lasts 2-4 hours
what binds irreversibly to acetylcholine
nerve gas and insecticides
to reverse cholinergic agonist (toxic effect)
cholinergic antagonist - atropine
if we block acetylcholine what system is going to dominate
sympathetic
antagonizing in cholinergic system acting on muscarinic receptors prototype
atropine - blocks acetylcholine - making sympathetic nervous system dominate
what acts on nicotinic receptors
neuromuscular blockers - acting on nicotinic receptors
2 ways neuromuscular blockers (nicotinic receptors) work
depolarizing or non-depolarizing - acting on skeletal muscles blocking the impulses with a result a paralysis of that muscle
cholinergic agonists have 2 actions what are they
directly (act like acteylcholine)
indirectly (binding to acetylcholinesterase)
prototype for DIRECT acting cholinergic/muscarinic agonist (
bethanecol chloride
bethanecol chloride is given for
post-op/postpartum urinary retention
how does bethanecol work
relaxes sphincter muscles - increases voiding pressure - increasing peristalsis in urinary system
when wouldn’t you want to give bethanecol
a blockage causing rupture (will still cause peristalsis)
what is bethanecol contraindicated for
asthma/copd patients (parasympathetic nervous system constricts bronchioles)
cholinergic adverse effects
reflect system they are stimulating
if you take too much of a cholinergic agonist what will it cause, whether direct or indirect
cholinergic crises
prototype for myasthenia gravis (INDIRECT cholinergic agonist - ache inhibitor)
neostigmine
if pt is in cholinergic crisis what can you give to reverse it
atropine (not long lasting) and supportive therapy
are indirect cholinergic agonists reversible
yes
most common 1st symptom of myasthenia gravis
eye droop/lid lag
what does neostigmine do
makes more acetylcholine, receptors are being destroyed to keep make muscles stronger
what time of day are the muscles exhausted in myasthenia gravis
night-time
what should a pt. on neostigmine do
keep diary - how was muscle strength/when it was time for the next dose
if muscle strength is good at time of next dose what do we do with the dosage
keep the dose the same - if weak muscle, increase dose
what is important for a pt to wear if they are dx with myasthenia gravis
medic alert bracelet
if pt is in ER and we need to determine whether they are in a myasthenia vs a cholinergic crises what can we do
***tensillon or edrophonium test
what happens in a tesnillon/edrophonium test
give smallest dose of indirect acting cholinergic agonist (neostigmine)
if pt is in a myasthenic crises when given a tensillon/edrophonium test will they get better or worse
better
if tensillon is given and pt gets worse what type of crises are they in
cholinergic crises - give atropine
drugs that have a positive charge cant
cross the blood-brain barrier
