Cholinergic Drugs Flashcards
M1 receptor
Locations: autonomic ganglia and CNS
Gq signaling
Responses: Excitatory postsynaptic potential. Arousal, attention, analgesia
M2 receptor
Locations: SA and AV nodes; atrium and ventricle
Gi signaling
Responses: Slowed spontaneous depolariztion, hyperpolarization, decr conduction velocity, decr refractory period, decr contractile force, decr contractility
M3 receptor
Location: Smooth muscle
Gq signaling
Contraction of smooth muscle
M4 receptor
Location: CNS
Gi signaling
M5 receptor
location: CNS
Gq signaling
Nm receptor
Location: Skeletal muscle at neuromuscular junction
Na/K channels
End-plate depol; skeletal muscle contraction
Nn receptor
Location: autonomic ganglia; adrenal medulla; CNS
Na/K channels
Depol and firing of postganglionic neuron; secretion of catecholamines; arousal, attn, analgesia
Donepezil, rivastigmine, galantamine
AChE inhibitors; used in tx of Alzheimer’s
S/e include diarrhea, N & V, cramps, anorexia, vivid dreams
Benztropine and trihexyphenidyl
Anti-muscarinics that reduce cholinergic tone in CNS to treat pts w/ Parkinson’s disease
Scopolamine, atropine, and hyoscyamine
Anti-muscarinics used to induce mydriasis (dilated pupils) to observe structures w/in inner eye
Pilocarpine and physostigmine
Muscarinic agonist/AChhE inhibitor used to treat acute angle glaucoma by inducing miosis
Ipratropium and tiatropium
M3-antagonists used to treat asthma as alternatives to beta-2 agonists
Complications include paralytic ileus, anaphylaxis, oropharyngeal edema
Tiotropium has a long T1/2 and is also used for COPD tx
Oxybutynin, glycopyrrolate, and benztropine
Anti-cholinergics that treat hyperhidrosis (excessive sweating)
Atropine
Muscarinic antagonist
Used to treat bradycardia, amanita mushroom poisoning, excess salivation
Contraindicated in narrow angle glaucoma
S/e include cardiac arrhythmia, respiratory depression, incr intraocular pressure, xerostomia, constipation
Oxybutynin
Muscarinic antagonist used to treat frequent urination and hyperhidrosis
Neostigmine
Used to treat paralytic ileus (disruption of normal peristaltic movements of GI tract)
Pilocarpine
Cholinergic agonist used to treat xerostomia (dry mouth) and acute angle glaucoma by inducing miosis
Pirenzepine
M1-antagonist that blocks muscarinic input on enterochromaffin-like cells, blocking their stimulation and release of histamine (histamine binds to parietal cells in stomach and causes incr acid release)
Pyridostigmine
AChE inhibitor used to treat pseudoobstruction of GI tract
Amanita muscaria
Deadly mushroom that secretes muscarine, which overly stimulates muscarinic receptors, leading to weakness, bradycardia, bronchoconstriction,dehydration due to sweating
Antidote is a muscarinic antagonist such as atropine
Organophosphates
Inhibits AChE, causing excessive contraction of muscles, excess sweating, bradycardia, bronchoconstriction, hypotension
Tetanus toxin
Degrades SNARE protein synaptobrevin, which is v-SNARE that binds to SNAP-25 and syntaxin and brings the vesicle to the membrane
Results in inability to release GABA into the synapse, leading to trismus (lockjaw, risus sardomicus (facial spasms), and opisthotonos (arched back contraction)
Scopolamine
Anti-muscarinic that treats motion sickness and is given to induce mydiasis fot examination of inner eye structures
Contraindicated in narrow angle glaucoma
S/e include psychosis, somnolence, xerostomia, blurred vision
Lambert-Eaton Syndrome
Caused by antibodies (AB) attacking voltage gated Ca channels in the terminal persynaptic axons. Leads to weakness, fatigue, blurred vision
Myasthenia gravis
Caused by autoimmune attack of cholinergic nicotinic receptors on postganglionic neuron. Symptoms are weakness, fatigue, blurred vision. Symptoms can be improved by giving an AChE inhibitor
Hemicholinium-3
Blocks choline reuptake; no clinical apps
Vesamicol
Blocks ACh uptake into transport vesicles; no clinical apps
Botulinum toxin
Digest one of the SNARE proteins to inhibit ACh transmission into the synapse
Used for focal dystonia, torticolis, wrinkles, hyperhidrosis, blepharospasm (uncontrolled muscle contraction)
S/e include cardiac arrhythmias, syncope, anaphylaxis, hepatotoxicity
AChE inhibitors
Edrophonium, neostigmine, pyridostigmine, ambenonium, physostigmine
Used to treat acute angle glaucoma, urinary/GI motility deficiencies, myasthenia gravis, antidote to anti-cholinergic toxicity
S/e include bronchoconstriction, bradycardia, cardiac arrest, hypotension, salivation, hyperhidrosis
Methacoline
Muscarinic agonist used for diff diagnosis of allergic asthma
Contraindicated in MI, CVA, aortic aneurysm, uncontrolled HT
Carbachol, bethanechol, cevimeline, pilocarpine
Tx of glaucoma, facilitate UG tract motility, xerostomia
Pancuronium, tubocurarine, vecuronium, rocuronium, mivacurium
Nicotinic receptor antagonists used to block muscle movement during surgery
Complications include HT, tachyarrhythmia, apnea, bronchospasm
