Cholinergic Drugs

Question 1

M1 receptor

Answer 1

Locations: autonomic ganglia and CNS

Gq signaling

Responses: Excitatory postsynaptic potential. Arousal, attention, analgesia

Question 2

M2 receptor

Answer 2

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

Question 3

M3 receptor

Answer 3

Location: Smooth muscle

Gq signaling

Contraction of smooth muscle

Question 4

M4 receptor

Answer 4

Location: CNS

Gi signaling

Question 5

M5 receptor

Answer 5

location: CNS

Gq signaling

Question 6

Nm receptor

Answer 6

Location: Skeletal muscle at neuromuscular junction

Na/K channels

End-plate depol; skeletal muscle contraction

Question 7

Nn receptor

Answer 7

Location: autonomic ganglia; adrenal medulla; CNS

Na/K channels

Depol and firing of postganglionic neuron; secretion of catecholamines; arousal, attn, analgesia

Question 8

Donepezil, rivastigmine, galantamine

Answer 8

AChE inhibitors; used in tx of Alzheimer’s

S/e include diarrhea, N & V, cramps, anorexia, vivid dreams

Question 9

Benztropine and trihexyphenidyl

Answer 9

Anti-muscarinics that reduce cholinergic tone in CNS to treat pts w/ Parkinson’s disease

Question 10

Scopolamine, atropine, and hyoscyamine

Answer 10

Anti-muscarinics used to induce mydriasis (dilated pupils) to observe structures w/in inner eye

Question 11

Pilocarpine and physostigmine

Answer 11

Muscarinic agonist/AChhE inhibitor used to treat acute angle glaucoma by inducing miosis

Question 12

Ipratropium and tiatropium

Answer 12

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

Question 13

Oxybutynin, glycopyrrolate, and benztropine

Answer 13

Anti-cholinergics that treat hyperhidrosis (excessive sweating)

Question 14

Atropine

Answer 14

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

Question 15

Oxybutynin

Answer 15

Muscarinic antagonist used to treat frequent urination and hyperhidrosis

Question 16

Neostigmine

Answer 16

Used to treat paralytic ileus (disruption of normal peristaltic movements of GI tract)

Question 17

Pilocarpine

Answer 17

Cholinergic agonist used to treat xerostomia (dry mouth) and acute angle glaucoma by inducing miosis

Question 18

Pirenzepine

Answer 18

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)

Question 19

Pyridostigmine

Answer 19

AChE inhibitor used to treat pseudoobstruction of GI tract

Question 20

Amanita muscaria

Answer 20

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

Question 21

Organophosphates

Answer 21

Inhibits AChE, causing excessive contraction of muscles, excess sweating, bradycardia, bronchoconstriction, hypotension

Question 22

Tetanus toxin

Answer 22

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)

Question 23

Scopolamine

Answer 23

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

Question 24

Lambert-Eaton Syndrome

Answer 24

Caused by antibodies (AB) attacking voltage gated Ca channels in the terminal persynaptic axons. Leads to weakness, fatigue, blurred vision

Question 25

Myasthenia gravis

Answer 25

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

Question 26

Hemicholinium-3

Answer 26

Blocks choline reuptake; no clinical apps

Question 27

Vesamicol

Answer 27

Blocks ACh uptake into transport vesicles; no clinical apps

Question 28

Botulinum toxin

Answer 28

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

Question 29

AChE inhibitors

Answer 29

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

Question 30

Methacoline

Answer 30

Muscarinic agonist used for diff diagnosis of allergic asthma

Contraindicated in MI, CVA, aortic aneurysm, uncontrolled HT

Question 31

Carbachol, bethanechol, cevimeline, pilocarpine

Answer 31

Tx of glaucoma, facilitate UG tract motility, xerostomia

Question 32

Pancuronium, tubocurarine, vecuronium, rocuronium, mivacurium

Answer 32

Nicotinic receptor antagonists used to block muscle movement during surgery

Complications include HT, tachyarrhythmia, apnea, bronchospasm