Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PNS/Cardiology > Muscarinic Agonists and Antagonists > Flashcards

Muscarinic Agonists and Antagonists Flashcards

1
Q

What G protein receptor is used for M1, M2, and M3?

A

M1 and M3 - Gq

M2 - Gi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the postreceptor mechanism of Gq?

A

Phospholipase C, IP3, DAG mediated cascade, causes intracellular release of calcium
= muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the postreceptor mechanism of Gi?

A

Blocks adenylylcyclase, causing inhibition of cAMP production and activation of K+ channels
= prevention of muscle relaxation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What drugs are muscarinic agonists?

A

Carbamylcholine (carbachol)
Acetyl-beta-methylcholine (methacholine)
Bethanechol
Pilocarpine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which muscarinic agonist is not resistant to hydrolysis by AChE?

A

Acetyl-beta-methylcholine (methacholine)

Slowly hydrolyzed by AChE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which muscarinic agonists are selective for specific muscarinic receptors?

A

None! No selective agonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which muscarinic agonist is more selective for nicotinic receptors than muscarinic?

A

Carbamylcholine (carbachol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which muscarinic agonist has best potency at M2 receptors (cardiac)?

A

Acetyl-beta-methylcholine (methacholine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which muscarinic agonist has no selectivity for nicotinic receptors?

A

Bethanechol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which muscarinic agonist can penetrate the BBB and membranes?

A

Pilocarpine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are symptoms of parasympathetic overstimulation?

A 
DUMBBELSS
Diarrhea
Urination
Miosis
Bronchoconstriction
Bradycardia
Emesis
Lacrimation
Salivation
Sweating
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the clinical uses of carbamylcholine (carbachol)?

A

Glaucoma (constriction of sphincter and drainage of fluid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the clinical uses of acetyl-beta-methylcholine (methacholine)?

A

When inhaled, causes bronchoconstriction (challenge test for asthma diagnosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the clinical uses of bethanechol?

A

GI disorders: postoperative ileus, congenital megacolon, GERD

Urinary retention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the clinical uses of pilocarpine?

A

Glaucoma (constriction of sphincter and drainage of fluid)

Xerostomia (dry mouth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the clinical uses of miochol (just is drug name for ACh)?

A

Cataract extraction

17
Q

What are contraindications to the use of muscarinic agonists?

A

Asthma - don’t want to bronchoconstrict
Hyperthyroidism - tendency for atrial fibrillation, don’t want to affect heart pacing
Coronary insufficiency - bradycardia, reduced cardiac output, reduced blood flow through coronary vessels
Peptic ulcer - activation of M1 receptors increases gastric secretion
Mechanical obstruction of GI tract - gastric motility contraindicated

18
Q

What drugs are muscarinic antagonists?

A 
Atropine
Scopolamine
Tropicamide
Glycopyrrolate
Cyclopentolate
Pirenzepine
Tiotropium, Ipatropium
Tolterodine, Darifenacin
19
Q

Which muscarinic antagonists are non-selective?

A 
Atropine
Scopolamine
Tropicamide
Glycopyrrolate
Cyclopentolate
20
Q

Which muscarinic antagonists are highly selective for M1?

A

Pirenzepine

Tiotropium, Ipatropium

21
Q

Which muscarinic antagonists are highly selective for M3?

A

Tiotropium, Ipatropium
Tolterodine
Darifenacin

22
Q

What are symptoms of blockade of parasympathetic stimulation?

A 
Blocks DUMBBELSS, causing:
Reduced GI motility
Urinary retention
Mydriasis
Bronchodilation
Tachycardia
Lack of emesis
Decreased lacrimation (dry eye)
Decreased sweat (dry skin)
Decreased salivation (dry mouth)
23
Q

What muscarinic antagonists are used to treat respiratory illnesses like cold and chronic bronchitis and emphysema?

A

Tiotropium, Ipatropium

Opens bronchi, reduce secretions, but no effect on sputum viscosity

24
Q

What muscarinic antagonists are used to treat GI hypermotility?

A

Glycopyrrolate

25
Q

What muscarinic antagonists are used to treat stomach ulcers?

A

Pirenzepine

26
Q

What muscarinic antagonists are used to treat overactive bladder?

A

Darifenacin, Tolterodine

M3 selective; have higher selectivity for M3 in detrussor muscle than in salivary glands

27
Q

What muscarinic antagonists are used Pre-anesthesia (to inhibit salivation and respiratory secretions to put in endotracheal tube)?

A

Atropine

Glycopyrrolate

28
Q

What muscarinic antagonists are used Post-anesthesia (prevent muscarinic activation by AChE inhibitor given to counteract muscle relaxant given earlier)?

A

Atropine
Glycopyrrolate

Scopolamine also used post anesthesia but used because at high doses it may tranquilize and produce amnesia following surgery

29
Q

What muscarinic antagonists are used to cause mydriasis for eye examination?

A

Tropicamide

Cyclopentolate

30
Q

What muscarinic antagonists are used to treat motion sickness?

A

Scopolamine

Transdermal patch behind ear allows diffusion of scopolamine to M1 receptors in inner ear

31
Q

What are contraindications to the use of muscarinic antagonists?

A

Narrow-angle glaucoma - dilated iris blocks exit of aqueous humor through trabeculum
Cardiac arrhythmia - similar to muscarinic agonists, do not want to disrupt heart rhythm
Chronic lung disease - via drying effect

32
Q

What is a common cause of muscarine poisoning?

A

Mushrooms, specifically Inocybe, Clitocybe, Amanita muscaria

33
Q

What is the treatment for muscarine poisoning?

A

Atropine

PNS/Cardiology (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions