Cholinergic Agonists

Question 1

Choline esters - name 3.

Answer 1

Methancol
Carbachol
Bethanecol

Question 2

Bethanechol - what is the action?

Answer 2

“Beth - call me to activate your BOWEL and BLADDER”

activates bowel and bladder via Muscarinic receptors
resistant to AChE

Question 3

Carbachol

Answer 3

“A carbon copy of ACh”
stimulates nicotinic and muscarinic
pupillary constriction, relieves intraoccular pressure

Question 4

Methacholine

Answer 4

Stimulates muscarinic receptors in airway when inhaled

Use as challenge test for asthma ddx.

Question 5

Alkaloids - give several examples

Answer 5

Muscarine
Pilocarpine
Oxotremorine
Nicotine

Question 6

What occurs with muscarinic stimulation of the eye?

Answer 6

Constricts pupil
Facilitates NEAR vision
decreases intra ocular pressure
Think: GLAUCOMA - pilocarpine given

Question 7

What occurs with muscarinic stimulation of the heart?

Answer 7

Muscarinic stim –> vagal stimulation = BRADYCARDIA!
Atrial and SA nodes effected
AV NODE IS SLOWED

Question 8

Blood vessels have what type of receptors?

Answer 8

M3

Question 9

Stimulation of M3 receptors on BV leads to what?

Answer 9

Dilation of vessels via NO release.

Question 10

Muscarinic agonists do what to the lungs?

Answer 10

Bronchoconstrict
Increase bronchiole secretions

This is why we give methacholine to challenge asthma ddx.

Question 11

Name a muscarinic agonist that increases cholingergic effect and has a STRANGE side effect.

Answer 11

Arecoline –> causes red saliva

Question 12

When treating glaucoma, what do we use?

Answer 12

Drops into eye to open angle.

Use with atropine to break adhesions between iris and lens.

Question 13

What is a side effect of treating with pilocarpine?

Answer 13

Salivation, sweating.

2-3L sometimes.

Question 14

What is cevimeline?

Answer 14

A selective M3 agonist.
Less side effects, longer action.
Less sweater.

Question 15

Side effects from muscarinic side effects?

Answer 15

Sweat
increased gut activity
drooling
bronchospasm
tears

Question 16

Why is poisoning with mushrooms a concern? What do we treat with?

Answer 16

Mushrooms are muscarine agonists.

Treat with atropine (ANTAGONIST) and Epi.

Question 17

Which receptors sensitize rapidly?

Answer 17

Nicotinic

Question 18

Compare low dose nicotinic stimulation in brain to high dose stimulation?

Answer 18

Low dose:
increased alertness and attention

High Dose
tremor, emesis, increased RR

Toxicity:
convulsions

Question 19

Does Nicotine activate PSNS or SNS?

Answer 19

Both!

Question 20

What are some effects of Nicotine toxicity?

Answer 20

vomiting
CNS overstim (convulsions, coma, respiratory arrest)
Skeletal mm depol (blocks NMJ and get paralysis)
Cardio: HTN and arrhythmia

Question 21

How to treat nicotine poisoning?

Answer 21

Atropine blocks M receptors
Anticonvulsant
Assist Respiration

Question 22

What does Chantix do?

Answer 22

partial agonist on nicotine receptor in brain
prevents cravings
blocks effect of nicotine if smoke

Question 23

Name some cholinesterase inhibitors?

Answer 23

“-stigmines” and “-phoniums”

Neostigmine (myasthenia gravis)
Physostigmine
Donezipil
Edrophonium (myasthenia gravis)

Question 24

What is one toxic substance that works as a cholinesterase inhibitor?

Answer 24

Organophosphates

Question 25

What's are some concerns with Neostigmine?

Answer 25

Use post op to remove neuromuscular blockade (NMB), but has poor oral absorption and doesn't enter CNS. Use to increase bladder motility, treat MG, and reverse NMB

Question 26

What cholinesterase inhibitors enter the CNS?

Answer 26

Physostigmine Think it "phyxs" an atropine overdose Give in the eye

Question 27

Endrophonium - what is it good for?

Answer 27

Cholinesterase inhibitor | reversible, short acting

Question 28

What can we use against organophosphate poisoning?

Answer 28

2PAM - but not for carbamates!

Question 29

What is 2PAM?

Answer 29

binds and inhibits AChE most effective at NMJ does not enter CNS

Question 30

Some effects of AChE inhibitors?

Answer 30

CNS - improved alertness and memory Eye - meiosis GI, Bladder stim Respiratory- salivation, secretion, bronchoconstric

Question 31

Cardio effects of AChE inhibitors?

Answer 31

Sympathetics dominated by Nicotine So - see heart with bradycardia, decreased force BP has little effect - no cholinergic innervation

Question 32

What is Donezipil often used for?

Answer 32

Donezipil = aricept AChE inhibitor that penetrates CNS Also could be Aricept, Exelon, Reminyl, Cognex

Question 33

How does Echothiophate work? What do we use it for?

Answer 33

Organophosphate AChE inhibitor IRREVERSIBLE inhibition of AChE use topically to produce long lasting decrease in Pressure

Question 34

What is DFP? Why is it dangerous?

Answer 34

organophosphate irreversibly binds AChE lipid soluble, penetrates CNS

Question 35

How do soman, sarin, and tabun work?

Answer 35

neve gases | organophosphates

Question 36

How should we treat glaucoma?

Answer 36

Direct agonist: pilocarpine or carbachol (lowers P) Cholinesterase Inhib also could be used

Question 37

Two possible drugs for GI/Urinary?

Answer 37

Bethanechol more common | Used to also be neostigmine

Question 38

Name the TOXICITIES For AChE

Answer 38

``` SLUDGE salivation lacrimation urination defecation gastric distress emesis ```

Question 39

What do we give for organophosphate AChE inhibitor poisoning?

Answer 39

atropine 2-Pam if w/in 3-4hrs of exposure Diazepam for seizures

Question 40

What can cause carbamate AChE poisoning?

Answer 40

Sevin Baygon Temik