Direct-Acting Cholinergic Agonists Flashcards
involved in memory
M1
cause coronary vasodilation by nitric oxide (seen when ACh is injected IV)
M3
muscarinic agonist cardiovascular effects
blood vessels aren’t innervated by PNS, vagal stimulation isn’t much at therapeutic levels
respiratory effects of muscarinic stimulation
bronchoconstriction –> contraindicated in asthma, COPD
muscarinic agonist with the most GU and GI effects
Bethanechol
muscarinic agonists GU/GI effects
relax all the sphincters for urination/defecation
stimulate bladder detrusor muscle (push out urine)
increased secretory activity and peristalsis
muscarinic agonist that cause the most salivary secretion
pilocarpine**, cevimeline
pilocarpine is used to treat
narrow angle glaucoma, xerostomia
GI reasons not to give muscarinic agonists
peptic ulcer disease (increase secretions) bowel obstruction (increased peristalsis)
Side effects of pilocarpine
brow ache??
sweating
blurry vision
2 alkaloid muscarinic agonists
pilocarpine, muscarine
Xerostomia DOC and why
cevimeline
It’s selective for M1 receptors and therefore has fewer side effects
Longer lasting
treatments (2) for muscarine poisoning (poison mushrooms)
atropine (muscarinic antagonist)
albuterol (bronchodilates)
bethanechol is a
ester, quarternary ammonium compound (no CNS)
if continuously stimulated, nicotinic receptors
desensitize rapidly since nicotine is not rapidly hydrolyzed
low dose central effects of nicotinic stimulation
increases alertness/attention
dopamine release causes pleasure
high dose central effects of nicotinic stimulation
tremor, vomiting, increased respiration
peripheral effects of nicotinic stimulation
similar to discharge of both parasympathetic and sympathetic neurons
cardiac peripheral effects of nicotinic stimulation
sympathetic tone prevails: HTN, increased HR (modulated by reflex bradycardia)
GU/GU peripheral effects of nicotinic stimulation
parasympathetic tone prevails: N/V, urination
NMJ peripheral effects of nicotinic stimulation
muscle contractions followed by receptor desensitization
flaccid paralysis
treatment for nicotine poisoning
atropine (muscarinic antagonist)
anticonvulsants
mechanical respiration
nicotine poisoning symptoms
Vomiting convulsions coma respiratory arrest paralysis htn cardiac arrhythmias
partial agonist on Nn in brain
varenicline
uses of varenicline
smoking cessation: provides some dopamine to block cravings yet as a partial agonist decreases the full effects of nicotine (if smoked)
varencicline general side effects
N/V/C
HA
fatigue
flatulence
varencicline CNS side effects
sleep disturbance vivid nightmares psychosis mania anxiety suicide
