Cholinergic Receptors and Agents Acting at the NMJ

Question 0

Two types of nicotinic cholinergic receptors

Answer 0

Muscle type (neuromuscular) and neuronal (ganglional)

Question 1

Acetylcholine synthesis: rate-limiting step

Answer 1

Choline enters a neuron via carrier-mediated transport

Question 2

Tubocurarine: site of drug action

Answer 2

Nicotinic receptor antagonist

Question 3

Alpha-bungarotoxin: site of action

Answer 3

blocks postsynaptic nicotinic receptor

Question 4

Beta-bungarotoxin: site of action

Answer 4

blocks presynaptic RELEASE of neurotransmitters

Question 5

RECALL CHOLINOMIMETIC DRUGS DIAGRAM

Answer 5

RECALL!!!!!!!

Question 6

Direct-acting cholinoceptor agents [2]

Answer 6

Choline esters

Alkaloids

Question 7

Bethanechol, Carbachol: PK features

Answer 7

promotes micturition, B-methyl group present

Bethanechol is muscarinic, carbachol is muscarinic and nicotinic

Question 8

Pilocarpine: PK features

Answer 8

good lipid solubility, for glaucoma

acts on muscarinic receptor

Question 9

Nicotine: PK features

Answer 9

acts on nicotinic, similar to pilocarpine

Question 10

Varenicline: PK features

Answer 10

partial agonist at nicotinic receptors, high lipid solubility, used in nicotine patches

Question 11

[T/F] Site of drug action of peripherally-acting cholinesterases inhibitors is via degradation.

Answer 11

T.
They inhibit Achesterase and buterylcholinesterase to cause increase in concentration of Ach, which enhances cholinergic transmission

Question 12

Anticholinesterase: Edrophonium

Answer 12

short-acting, binds reversibly to anionic site of enzyme, mainly for diagnostic purposes

Question 13

Anticholinesterase: Neostigmine, Pyridostigmine, Physostigmine

Answer 13

medium-duration, maintenance drug for myasthenia gravis

Question 14

Anticholinesterase: Organophosphates

Answer 14

irreversible, permanently binds to and deactivates Achesterase

Question 15

Pralidoxime

Answer 15

a cholinesterase regenerator, antidote to organophosphate toxicity

Question 16

Toxicity of indirect-acting agents: Signs and symptoms

Answer 16

DUMBELS:
Diarrhea
Urination
Myosis
Bronchocostriction
Excitation
Lacrimation
Salivation

Question 17

[T/F] Centrally-acting cholinesterase inhibitors are used in the symptomatic treatment of Alzheimer’s disease and dementia.

Answer 17

T

Question 18

RECALL CHOLINOCEPTOR BLOCKERS AND CHOLINESTERASE REGENERATORS DIAGRAM

Answer 18

RECALL!!!!!!!!

Question 19

Cholinoceptor blockers: MOA

Answer 19

Inhibition of choline uptake
Inhibition of Ach release
Blocking of postsynaptic receptors or ion channels
Persistent postsynaptic depolarization

Question 20

Muscarinic antagonists examples

Answer 20

Atropine, Scopolamine

Question 21

Hemocholinium: site of action

Answer 21

Reuptake, blocks transport of choline

Question 22

Triethylcholine: site of action

Answer 22

Synthesis of NT, block transport of choline forms false NT

Question 23

Aminoglycoside antibiotics: site of action

Answer 23

blocks RELEASE of Ach

Question 24

Ganglion-blocking drugs: Mechanisms

Answer 24

interferes with Ach release
prolonged depolarization
interferes with postsynaptic action of Ach

Question 25

Depolarizing drugs: Mechanism

Answer 25

Phase I: depolarization block

Phase II: desensitizing block