Muscarinic Antagonists

Question 1

Anticholinergic drugs do what?

Answer 1

Antagonists that prevent acetylcholine signaling

Question 2

Antimuscarinic acts where?

Answer 2

Post ganglionic neuroeffector junction to block parasympathetic autonomic discharge

Question 3

Neuromuscular blocker acts where?

Answer 3

Neuromuscular junction to block acetylcholine signaling

Question 4

Ganglionic blockers act where?

Answer 4

They act as antagonists at both parasympathetic and sympathetic autonomic ganglia

Question 5

How do Muscarinic Receptors M1, M3, and M5 signal?

Answer 5

Via increase in intracellular Ca2+and PKC activity

Question 6

Where is M1 located? (3)

Answer 6

CNS
Sympathetic postganglionic cells
Presynaptic sites

Question 7

M3 locations? (3)

Answer 7

Smooth muscle
Lungs
Eyes effector cell membranes

Question 8

M2 and M4 are activated how?

Answer 8

Signal via cAMP decreased and reduced cAMP-dependent PK activity

Question 9

Where is M2 located? (3)

Answer 9

Myocardium
Smooth muscle
Presynaptic sites

Question 10

Where is M4? (1)

Answer 10

CNS

Question 11

Atropa Belladonna (deadly nightshade) gave us what?

Answer 11

Atropine

Question 12

Belladonna causes what effect in the eyes?

Answer 12

Increase in pupil size

Question 13

Antimuscarinic drug use in ocular exams? (2)

Answer 13

Mydyriasis (pupil dilation)

Cycloplegia (Loss of focus/regulation of lens thickness)

Question 14

Which M receptor is being targeted in antimuscarinic drugs?

Answer 14

M3

Question 15

How does Muscarinic antagonists affect incontinence?

Answer 15

Triggers bladder relaxation via M3 receptor which mediates contraction of bladder and M2 which inhibits relaxation

Question 16

Drug used in irritable bowel syndrome to induce GI paralysis and reduce secretions?

Answer 16

Mebeverine

Question 17

What other uses are listed for antimuscarinic drugs? (4)

Answer 17

COPD
Pre-Op Anti-Secretory
Motion Sickness
Parkinson’s disease

Question 18

For COPD use what is the effect of muscarinic antagonists? (2)

Answer 18

Reduce secretions

Cause Bronchial dilation

Question 19

In COPD use what would I combine antimuscarinic drugs with?

Answer 19

B-adrenergic agonist

Question 20

What is the purpose of anti-muscarinic in treating Parkinson’s?

Answer 20

Adjunct to L-DOPA

Question 21

What is the mechanism of Antimuscarinic drugs?

Answer 21

Competitive and reversible inhibition of muscarinic receptor activation by preventing the binding of Ach.

Question 22

Two classes of antimuscarinic?

Answer 22

Tertiary Amines (Atropine)
Quaternary Amines/Ammonium (Glycopyrrolate)

Question 23

Main use for Tertiary amines?

Answer 23

Ocular and CNS applications

Question 24

Main use of Quaternary Amines/Ammonium?

Answer 24

GI tract and peripheral application

Question 25

What specific tertiary amine do you use for COPD?

Answer 25

Ipratropium

Question 26

Characteristics of tertiary amines? (2)

Answer 26

Can penetrate CNS | Non-selective antagonists

Question 27

Which tertiary amine is better for CNS penetration?

Answer 27

Scopolamine is better than Atropine

Question 28

What happens in low vs high doses of Scopolamine?

Answer 28

Low doses you get drowsiness | High doses you get hallucination

Question 29

Why is Scopolamine not for children?

Answer 29

Toxicity

Question 30

How do you give Scopolamine locally?

Answer 30

Patch form

Question 31

Why is Scopolamine useful in surgery and childbirth?

Answer 31

Can cause amnesia

Question 32

When Scopolamine treatment is stopped what effects can be seen?

Answer 32

Rebound effects which cause overstimulation of vestibular and reticular formation of the vomiting center

Question 33

Short acting tertiary amine used in optical applications?

Answer 33

Tropicamide (0.25 days)

Question 34

What does Tropicamide cause? (2)

Answer 34

Cycloplegia (loss of accommodation) | Mydriasis

Question 35

Types of Urinary Incontinence? (4)

Answer 35

Stress (Leak) Urge (Nocturia) Outflow (Retention secondary to obstruction) Functional (Large volume intake)

Question 36

What do you treat stress incontinence with?

Answer 36

Adrenergic agonist

Question 37

What do you treat urge incontinence with?

Answer 37

Anti-cholinergics

Question 38

What do you treat outflow incontinence with?

Answer 38

Cholinergics for atony | alpha antagonists for obstruction

Question 39

Diabetic neuropathy can cause what two dysfunctions?

Answer 39

1) Diabetic bladder dysfunction | 2) Diabetic cystopathy

Question 40

What is diabetic bladder dysfunction?

Answer 40

Overactive bladder leading to urge incontinence

Question 41

What is diabetic cystopathy?

Answer 41

Decreased bladder sensation, increased capacity leading to outflow incontinence

Question 42

How does pregnancy affect the bladder?

Answer 42

Increased weight from baby damages bladder sphincter

Question 43

Effect of Congestive heart failure on bladder?

Answer 43

Retention of water causes more water in body causes too much urine causes nocturia

Question 44

What do muscarinic antagonists do for urinary incontinence? (2)

Answer 44

Suppress involuntary bladder contraction | Increase maximal urine volume that causes involuntary bladder contraction

Question 45

Which muscle in the bladder does M2 handle?

Answer 45

Detrusor

Question 46

Benefit of M3 selective Darifenacin or Solifenacin in urinary incontinence?

Answer 46

Longer acting than oxybutinin

Question 47

Benefit of M2/M3 selective Tolterodine?

Answer 47

Fewer side effects than oxybutinin

Question 48

Downside of Tolterodine?

Answer 48

Too much/too long use can lead to acute urinary retention

Question 49

Quaternary amine probanthine used for what?

Answer 49

Gastric disorders such as GI spasms/peptic ulcers

Question 50

What restricts Probanthine from crossing the gut?

Answer 50

Charged Nitrogen

Question 51

What type of restricted is Probanthine?

Answer 51

Peripherally

Question 52

Main antispasmodics for irritable bowel syndrome? (3)

Answer 52

Atropine Dicyclomine Hyoscyamine

Question 53

Who do you avoid giving antispasmodics to?

Answer 53

Glaucoma patients

Question 54

Which muscarinic receptors mediate constriction of bronchial smooth muscle?

Answer 54

M3 | So M3 antagonist will block Ach mediated constriction and open the airways

Question 55

M3 antagonists enhance what?

Answer 55

B-adrenergic agonists in COPD

Question 56

What is known as the "rescue inhaler"?

Answer 56

Ipratropium: short acting

Question 57

What is known as the daily inhaler?

Answer 57

Tiotropium: long acting

Question 58

What do tertiary amines for Parkinson's act on?

Answer 58

CNS M1 receptors

Question 59

What is the preferred Tri-cyclic Anti-depressant in elderly to moderate anticholinergic effects ?

Answer 59

Nortriptyline (Aventyl, Pamelor)

Question 60

Important drug in treating Parkinson's?

Answer 60

Trihexyphenldyl

Question 61

When do you not give anti muscarinic drugs? (4)

Answer 61

Glaucoma Tachycardia Intestinal obstruction Urinary obstruction