Drug Receptor Function

Question 1

How is acetylcholine synthesized? By what enzyme?

Answer 1

Synthesized from acetyl CoA and choline by choline acteyltransferase

Question 2

What is the rate limiting step of ACh synthesis?

Answer 2

Getting choline into the nerve

Question 3

How is ACh degraded? Into what products? By what enzyme? Where is the enzyme located?

Answer 3

ACh is degraded into acetic acid and choline by acteylcholinesterase located on the post-synaptic cell membrane

Question 4

What is the relative affinity for ACh to the nicotinic and muscarinic receptors?

Answer 4

Equal

Question 5

What are the muscarinic receptor subtypes and their location?

Answer 5

M1: Neuronal CNS/ ANS Presynaptic; M2: Cardiac; M3: Smooth Muscle and Glands and Vascular endothelium

Question 6

What are the classes of direct-acting cholinergic receptor agonists?

Answer 6

Choline esters and alkaloids

Question 7

What are the classes of cholinesterase inhibitors?

Answer 7

Carbamates and organophosphates

Question 8

What kind of drug is bethanechol? What are its uses?

Answer 8

Bethanechol is a choline ester muscarinic agonist used to prevent acute postoperative or postpartum non-obstructive urinary retention

Question 9

What kind of drug is carbachol? What are its uses?

Answer 9

A choline ester muscarinic and nicotinic agonist used to produce miosis during ocular surgery

Question 10

What kind of drug is pilocarpine? What are its uses?

Answer 10

Pilocarpine is an alkaloid selective muscarinic agonist used topically to treat glaucoma, xerostomia (dry mouth) or for Sjogren’s Syndrome

Question 11

What is Sjogren’s syndrome?

Answer 11

An autoimmune disease associated with dryness (lack of sweating, salivation)

Question 12

What kind of drug is cevimeline?

Answer 12

A synthetic muscarinic agonist approved for treatment of Sjogren’s syndrome

Question 13

What drugs are belladonna alkaloids that are muscarinic antagonists? What are the semi-synthetic derivatives of these drugs?

Answer 13

Atropine and scopolamine; Ipratropium, Tolterodine, Oxybutynin

Question 14

What are the symptoms of atropine overdose?

Answer 14

Dry, hot, red, blind, CNS problems/confusion (mad)

Question 15

What kind of drug is trimethaphan? What are its uses?

Answer 15

Trimethaphan is a ganglionic nicotinic antagonist used to produce controlled hypotension

Question 16

What are NMJ blockers used for?

Answer 16

To promote skeletal muscle relaxation during surgery

Question 17

What drug is a long duration, non-depolarizing NMJ blocker?

Answer 17

Tubocurarine

Question 18

What drug is a intermidiate duration, non-depolarizing NMJ blocker? Short duration?

Answer 18

Pancuronium; Mivacurium

Question 19

Why is succinylcholine considered an NMJ blocker even though it evokes depolarization upon binding?

Answer 19

It activates the nicotinic NMJ receptor longer than ACh, which leads to depletion of Ca++ stores and flaccid paralysis

Question 20

Is it better to use depolarizing or non-depolarizing NMJ blockers for short surgeries?

Answer 20

Depolarizing

Question 21

What is the antidote for overdose of non-depolarizing NMJ blocking agents? What kind of drug is it?

Answer 21

Neostigmine; AChE inhibitor

Question 22

What is the antidote for neostigmine overdose?

Answer 22

Tubocurarine

Question 23

What cholinergic drug can cause life-threatening hyperkalemia or malignant hyperthermia? What drug can be used to treat the malignant hyperthermia?

Answer 23

Succinylcholine; Dantolene

Question 24

How does Botox or Botulinum toxin work?

Answer 24

It cleaves SNARE proteins involved in the exocytosis of ACh vesicles, inhibiting the release

Question 25

What are the different categories of Cholinesterase inhibitors?

Answer 25

Short-acting (non-covalent inhibitors); Medium-duration (reversible carbamates); and Long-duration (‘irreversible organophosphates’)

Question 26

What kind of drug is edrophonium? What is it used for?

Answer 26

A very short acting, non-covalent, cholinesterase inhibitor used as a diagnostic agent for Myasthenia Gravis

Question 27

What are examples of carbamates that bind to the esteratic site of AChE?

Answer 27

Physostigmine, Neostigmine, and Pyridostigmine

Question 28

What is the drug of choice to treat poisoning with atropinic agents?

Answer 28

Physostigmine

Question 29

Which of the reversible carbamates readily penetrates the CNS? What conditions is it used to treat?

Answer 29

Physostigmine; Alzheimer’s and dementia

Question 30

What are Neostigmine and Pyridostigmine used to treat?

Answer 30

Myasthenia gravis or glaucoma

Question 31

What is the antidote used for overdose of organophosphate cholinesterase inhibitors?

Answer 31

2-PAM