2 - Cholinoceptor-Activating & Cholinesterase-Inhibiting Drugs

Question 1

Cholinergic drugs are also known as?

Answer 1

Parasympathomimetic agents, mimic ACh actions

Question 2

What are the 2 types of direct-acting drugs?

Answer 2

Alkaloids & Choline esters

Question 3

What receptors do direct-acting drugs act on?

Answer 3

Muscarinic & Nicotinic receptors

Question 4

Where are Muscarinic receptors found?

Answer 4

Nerves, Heart & smooth muscle, Glands & endothelium

Question 5

Where are Nicotinic receptors found?

Answer 5

Neuromuscular end plate, skeletal muscle, autonomic ganglion cells

Question 6

What are the 2 types of indirect-acting drugs?

Answer 6

Reversible & Irreversible

Question 7

Which cholinoceptor agonist crosses the BBB?

Answer 7

Physostigmine

Question 8

What are the 4 choline ester drugs?

Answer 8

ABCM: Acetylcholine, Bethanechol, Carbachol, Methacholine

Question 9

What is Methacholine’s MOA?

Answer 9

Its methyl group blocks nicotinic activity

Question 10

What is Bethanechol’s MOA?

Answer 10

Its carbamoyl group blocks hydrolysis

Question 11

All Muscarinic receptors are ____________ receptors

Answer 11

G-protein coupled

Question 12

What receptor activation results in electrical and ionic changes?

Answer 12

Nicotinic receptor

Question 13

What receptor activation results in depolarization of the nerve cell or neuromuscular end plate membrane, causing a “depolarization blockade”?

Answer 13

Nicotinic receptor (abolishes the effector response)

Question 14

What receptor activation results in prolonged agonist occupancy?

Answer 14

Nicotinic receptor

Question 15

Which receptor activation can result in muscle paralysis?

Answer 15

Nicotinic receptor

Question 16

What receptor activation results in activation of IP3 & DAG cascade?

Answer 16

Muscarinic receptor

Question 17

What receptor activation results in increase of potassium flux?

Answer 17

Muscarinic receptor

Question 18

____ receptors desensitize very quickly upon excessive stimulation

Answer 18

Nicotinic

Question 19

What are the 2 classes of Cholinesterase Reversible Inhibitors?

Answer 19

Simple alcohol ester (Edrophonium) & Carbamates (pseudo-reversible)

Question 20

What is the class of Cholinesterase Irreversible Inhibitors?

Answer 20

Organophosphates

Question 21

What 2 enzymes do cholinesterase inhibitors inhibit?

Answer 21

Acetylcholinesterase (primary) & Butyrylcholinesterase

Question 22

_________ bear a quaternary ammonium group that cannot enter the CNS

Answer 22

Simple alcohols

Question 23

______ bear a quaternary ammonium group that cannot enter the CNS OR a tertiary ammonium group that CAN enter the CNS

Answer 23

Carbamic acid/Carbamate esters

Question 24

________ compete for ACh at the enzyme

Answer 24

Simple alcohols

Question 25

_______ carbamoylate the active site

Answer 25

Carbamic acid/Carbamate esters

Question 26

_______ has a tertiary ammonium group

Answer 26

Physostigmine

Question 27

_______ phosphorylate the active site

Answer 27

Organophosphates

Question 28

_______ reversibly bind to the active site

Answer 28

Quaternary alcohols

Question 29

_______ undergo a two-step hydrolysis

Answer 29

Carbamic acid/Carbamate esters

Question 30

What group causes the longest inhibition time?

Answer 30

Organophosphates

Question 31

What group causes the shortest inhibition time?

Answer 31

Quaternary alcohols

Question 32

In which 2 groups is the enzyme reactivated?

Answer 32

Carbamate esters & Organophosphates

Question 33

What organs have prominent effects from cholinesterase inhibitors?

Answer 33

Cardiovascular & GI systems, eye, skeletal muscle

Question 34

T/F: Cholinesterase inhibitors have a large effect on vascular smooth muscle & blood pressure

Answer 34

False, they have a low effect

Question 35

T/F: Cholinesterase inhibitors amplify the actions of endogenous acetylcholine

Answer 35

True

Question 36

At NMJ, what happens with low concentrations of cholinesterase inhibitors?

Answer 36

Increased force of contraction in neuromuscular junction

Question 37

At NMJ, what happens with high concentrations of cholinesterase inhibitors?

Answer 37

Depolarizing neuromuscular blockade

Question 38

Cholinesterase Inhibitors Toxicity: SLUDGE DUMBBELSS stands for?

Answer 38

Salivation, Lacrimation, Urinary incontinence, Diarrhea, GI cramps, Emesis Diarrhea, Urination, Miosis, Bronchoconstriction, Bradycardia, Excitation/Emesis, Lacrimation, Salivation, Sweating

Question 39

Acute toxicity from cholinesterase inhibitors can be reversed by? (2)

Answer 39

Atropine (muscarinic antagonist) or pralidoxime

Question 40

M1 & M3 antagonist, used for Sjogren's syndrome & post-radiation xerostomia (dry mouth)

Answer 40

Cevimeline

Question 41

Partial agonist of nicotine receptors, used in smoking cessation

Answer 41

Varenicline