Cholinergics:Muscarinic Receptor Antagonist

Question 1

competitively block muscarinic receptors (parasympatholytics, antimuscarinics)

Answer 1

Muscarinic receptor antagonist

Question 2

Are muscarinic receptor antagonists selective for receptor subtypes?

Answer 2

no

Question 3

Effect of muscarinic receptor antagonist:

_____ iris sphincter and ciliary muscles – mydriasis and paralysis of accommodation (cycloplegia)

Answer 3

relax

Question 4

Effect of muscarinic receptor antagonist:

_______ non-vascular smooth muscle (airways, GI tract, urinary bladder)

Answer 4

relax

Question 5

Effect of muscarinic receptor antagonist:

_______ heart rate

Answer 5

increase

Question 6

Effect of muscarinic receptor antagonist:

______ exocrine gland secretion (sweat, salivary, lacrimal, intestinal, mucosal glands)

Answer 6

inhibit

Question 7

Effect of muscarinic receptor antagonist:
CNS effects
- low (therapeutic) doses produce _______
- higher, toxic doses produce _________

Answer 7

sedation

excitement, delirium, agitation, toxic psychosis

Question 8

muscarinic receptor antagonist:

effectively treat bradyarrhythmias due to high vagal tone~~~ specifically MI or hyperactive carotid reflex

Answer 8

Atropine

Question 9

muscarinic receptor antagonist:

to produce mydriasis (dilation) and cylcoplegia (paralysis of accommodation)

Answer 9

Atropine

Question 10

Duration of action of Atropine

Answer 10

• long duration of action (7-10 days) -

Question 11

What drug would I use to allow for thorough examination of the retina and optic disc
and to allow certain surgical procedures - treat acute iritis or choroiditis

Answer 11

Atropine

Question 12

muscarinic receptor antagonist:
uses in anesthesia: - commonly given to block responses to vagal reflexes induced by
surgical manipulation of visceral organs

Answer 12

Atropine

Question 13

• use to treat anticholinesterase or muscarinic toxicity

Answer 13

Atropine

Question 14

tx motion sickness

Answer 14

Scopolamine

Question 15

Which penetrates CNS better: scopolamine or atropine

Answer 15

scopolamine

Question 16

which alkaloid muscarinic receptor antagonist works through CNS?

Answer 16

scopolamine

Question 17

Use to tx vestibular disease

Answer 17

scopolamine

Question 18

Used to tx crhonic obstructive pulmonary disease

Answer 18

Ipratropium

Question 19

Good for COPD but less so for asthma

Answer 19

Ipratropium

Question 20

Drug that reduces secreations and reduces bronchoconstriction

Answer 20

Ipratropium

Question 21

Adminstration of Ipratropium

Answer 21

inhialer

Question 22

Does Ipratropium penetrate CNS?

Answer 22

No

Question 23

How does Ipratropium tx COPD

Answer 23

reduces bronchoconstriction and reduced secreations

Question 24

Good for fast eye dialation

Answer 24

Tropicamide

Question 25

Tropicamide effects

Answer 25

dialation and paralysis of ciliary muscle so loss of accomidation

Question 26

Tropicamide is what type of drug

Answer 26

Muscarinic receptor antagonist

Question 27

Tropicamide has fast/slow onset and long or short duration

Answer 27

fast onset and short duration

Question 28

- used to treat overactive bladder and incontinence | bad choice

Answer 28

Oxybutynin

Question 29

Whats the downside of using oxybutynin?

Answer 29

- high incidence of anti-muscarinic side effects | - xerostomia mainly, but also blurred vision, GI (constipation) & CNS (drowsiness, confusion) antimuscarinic effects

Question 30

- used to treat overactive bladder and incontinence (good choice)

Answer 30

Darifenacin

Question 31

Why is darifenacin a better choice then oxybutynin for overactive bladder?

Answer 31

selective M3 blocker so less CNS side effects

Question 32

used to block parasympathomimetic effects during reversal of neuromuscular blockade with anticholinesterase agents

Answer 32

Glycopyrrolate

Question 33

Glycopyrrolate penetrate CNS?

Answer 33

quaternary amine so no CNS penetration

Question 34

If you use neostigmine to reverse skeletal muscle paralysis, you get parasympathomimetic effect... you can use _______ so we don't overdo it with the neostigmine

Answer 34

Glycopyrrolate

Question 35

Glycopyrrolate stops what type of symptoms from neostigmine

Answer 35

SLUDGE

Question 36

Side effects of muscarinic receptor agonists

Answer 36

- Hot as a hare (no sweating) - Dry as a bone (dry mouth, dry hot skin, no sweating) - Red as a beet (due to excessive heat and no sweating) - Blind as a bat (mydriasis, cycloplegia, blurred vision) - Drowsiness (CNS action)

Question 37

Three pt profiles to be careful when using muscarinic receptor antagonists

Answer 37

Glaucoma (d/t eye issues) Benign Prosthetic hyperplasia (already have issues urinating) Any pt with tachycardia

Question 38

What drug do we use to tx poisoning of muscarinic receptor agonists?

Answer 38

physostigmine if severe bc it's an AchE inhibitor that will penetrate CNS