Muscarinic Antagonists

Question 1

Effects of M1, M3, and M5 activation?

Answer 1

Signal via intracellular Ca2+ increase and PKC activity

Question 2

Effects of M2, M4 activation?

Answer 2

Signal via cAMP, decrease cAMP-dependent PK activity

Question 3

Important sites of M1?

Answer 3

Present in CNS, sympathetic postganglionic, and presynaptic sites

Question 4

Important sites of M3?

Answer 4

Smooth Muscle, Lungs, Eyes, Effector Cell Membranes

Question 5

Important sites of M2?

Answer 5

Myocardium, Smooth Muscle, Presynaptic sites

slows the heart rate

Question 6

Important sites of M4?

Answer 6

CNS

Question 7

Primary clinical uses for anti-muscarinic drugs?

Answer 7

Ocular Exams
Incontinence
Irritable Bowel Syndrome

Question 8

Use of anti-muscarinic drugs in ocular exams?

Answer 8

Inhibit ACh activation of M3 of pupillary constrictor–> Mydyriasis
Inhibit ACh on M3 in cilliary muscle –> Cycloplegia

Question 9

What is cycloplegia

Answer 9

Loss of accomodation/regulation of lens thickness

Question 10

Effects of anti-muscarinic drugs on incontinence?

Answer 10

Trigger bladder relaxation via blockage of the M3 receptor (which normally contracts the bladder), and M2 (indirectly), which would inhibit relaxation

Question 11

use of anti-muscarinic drugs in treatment of IBS?

Answer 11

Induce GI tract intestinal paralysis

Reduce secretions

Question 12

Name the anti-muscarinic drug used to treat IBS?

Answer 12

Mebeverine

Question 13

Less popular uses for anti-muscarinic drugs?

Answer 13

COPD (can decrease secretions, dilate bronchioles)
Pre-Operative anti-secretor
Motion Sickness
Parkinson’s (as an adjunct to L-dopa)

Question 14

What are the two types of muscarinic antagonists?

Answer 14

Those with a tertiary amine and those with a quaternary amine

Question 15

Downside of muscarinic antagonists with a quaternary amine?

Answer 15

Solubility issues – only for GI or peripheral applications

Question 16

Within the antagonist structure you can recognize which structure…

Answer 16

acetylcholine

Question 17

How are tertiary amines muscarinic antagonists?

Answer 17

Ocular and CNS applications

Question 18

Two common non-selective muscarinic antagonists?

Answer 18

Atropine and Scopolamine

Question 19

Use of Atropine and Scopolamine?

Answer 19

Long duration of action

useful in treatment of GI/urinary conditions, COPD, and motion sickness

Question 20

Atropine and Scopolamine. Who penetrates the CNS more?

Answer 20

Scopolamine

Thats why is can cause CNS side effects (ex. drowsiness)

Question 21

Uses of Scopolamine specifically?

Answer 21

Surgical amnesia

Motion sickness patch

Question 22

Problems with Scopolamine use?

Answer 22

Prolonged use can cause withdrawl effects upon termination of treatment

Question 23

How to treat Scopolamine withdrawl?

Answer 23

Anti-histamines

Leave the patch on to squeeze out meds over an extended period

Question 24

Indication for Tropicamide?

Answer 24

Cause cycloplegia and mydriasis with shorter duration than atropine. Allows for examination of the terminal ends of the optic nerve.

Question 25

What are the four types of urinary incontinence?

Answer 25

Stress Incontinence Urge Incontinence Outflow Incontinence Functional Incontinence

Question 26

Important Information for Stress Incontinence?

Answer 26

Laxity of pelvic floor muscle Associated with leak with cough/laugh, vaginal childbirth Treat with adrenergic agonists

Question 27

Important information for Urge Incontinence?

Answer 27

Increased detrusor muscle activity (Overactive bladder) Nocturia, small volume, increased frequency Treat with anti cholinergics

Question 28

Important information about outflow incontinence?

Answer 28

Urinary retention secondary to obstruction or bladder atony Nocturia, small volume, increased frequency Treat with cholinergics (atony), alpha antagonists (obstruction)

Question 29

Cause of functional incontinence

Answer 29

Large volume intake

Question 30

Diabetic cystopathy can lead to what kind of incontinence?

Answer 30

Outflow incontinence

Question 31

Effect of gestational diabetes on bladder fxn?

Answer 31

damage to bladder sphincter

Question 32

leftover urine is a problem because it can lead to...

Answer 32

Increased urge and frequency

Question 33

Effect of muscarinic antagonists on urinary incontinence?

Answer 33

Suppress bladder contraction | Increase maximal urine volume that causes contraction

Question 34

Examples of M3 selective muscarinic antagonists in treating incontinence? Whats so cool about them?

Answer 34

Darifenacin and Solifenacin | Longer acting than oxybutiin

Question 35

Examples of M2/M3 selective muscarinic antagonists used in urinary incontinence? Whats so cool about them?

Answer 35

Tolterodine | Fewer Side Effects

Question 36

Example of an M1/M3 selective muscarinic antagonists used for urinary incontinence?

Answer 36

Oxybutynin

Question 37

What is Probanthine? When do you use it?

Answer 37

A quaternary aminemuscarinic antagonist used in treatment of GI spasms, peptic ulcers.

Question 38

Three examples of muscarinic antagonists used as anti-spasmodics.

Answer 38

Atropine Dicyclomine Hyoscyamine

Question 39

Who shouldn't be taking muscarinic antagonist anti-spasmodic drugs?

Answer 39

Glaucoma patients | Long term use

Question 40

What drugs are used in muscarinic antagonist treatment of COPD?

Answer 40

IPRAtropium (short acting rescue inhaler) TIOtropium (long acting daily inhaler) LAMA (Long acting Musc. antagonists).

Question 41

muscarinic antagonist treatments of COPD are typically paired with...

Answer 41

beta-adrenergic agonists

Question 42

muscarinic antagonists used in treatment of Parkinsons?

Answer 42

Benztropine | Trihexyphenidyl

Question 43

What receptor do Benztropine and Trihexyphenidyl act on?

Answer 43

M1 Receptor

Question 44

Benztropine and Trihexyphenidyl are adjunct therapies paired with ______

Answer 44

L-dopa

Question 45

What do Benztropine and Trihexyphenidyl do to help Parkinson's?

Answer 45

Improve the balance between dopaminergic and cholinergic neurotransmission

Question 46

List drug classes known to have anti-cholinergic activity

Answer 46

Anti-histamines Anti-psychotics Tricyclic Antidepressants Anti-arrythmetics

Question 47

Nortriptyline is preferred the preferred TCA for the elderly. Why?

Answer 47

Mild/Moderate anti-cholinergic effects

Question 48

Four common contraindications for antimuscarinic drugs?

Answer 48

Open/Narrow Angle Glaucoma Tachycardia Ileus (Intestinal Obstruction) Urinary Obstruction (causes benign prostatic hyperplasia)