Antimuscarinic Drugs

Front 1

What are the three major groups which classify drugs that block ACh receptors?

Back 1

Neuromuscular blockers, ganglion blockers, and antimuscarinic blockers

Front 2

Neuromuscular Blockers

Back 2

-are antagonist at nicotinic ACh receptors in skeletal muscle tissue, part of the somatic nervous system

Front 3

Ganglion Blockers

Back 3

Antagonize nicotinic ACh receptors in the ganglia

Front 4

Antimuscarinic Drugs

Back 4

ACh receptor antagonist

Front 5

What are the 2 naturally occuring antimuscarinic drugs?

Back 5

Atropine and Scopolamine

Front 6

What two plant sources can atropine be isolated from?

Back 6

Atropa belladonna (deadly nightshade) and Datura stramonum (jimsonweed)

Front 7

How does Atropine occur in nature relative to commerical purposes?

Back 7

In nature, Atropine occurs as a single enantiomer, but when isolated for commercial purposes it forms a racemic mixture.

Front 8

When Atropine is in its natural, single enantiomer state, what is referred to?

Back 8

Hyoscyamine

Front 9

What is the synthetic derivative that is very similar in chemical structuire to the naturally occurring atropine and scopolamine?

Back 9

Homatropine

Front 10

Quaternary Amine Antimuscarinics

Back 10

1. Have a permanently charged nitrogen atom that increases the overall polarity relative to the tertiary amine antimuscarinics.
2. Have more peripheral effects

Front 11

TRUE/FALSE. Polar drugs distribute well to the CNS.

Back 11

FALSE. Polar drugs DO NOT distribute well to the CNS

Front 12

Name 3 Quaternary Amine antimuscarinic drugs.

Back 12

Ipratropium, Tiotropium, and Trospium Chloride

Front 13

Tertiary Amines

Back 13

1. Have more CNS effects
2. Less polar then quaternary amine antimuscarinics

Front 14

Name the 6 Tertiary Amine Antimuscarinic drugs.

Back 14

Benztropine, Dicyclomine, Oxybutynin, Tolterodine, Darifenacin, Solifenacin "SOB DDT"

Front 15

TRUE/FALSE. Synthetic antimuscarinic analogs tend to have less selectivity to muscarinic ACh receptors.

Back 15

TRUE. Synthetic antimuscarinic analogs tend to have less selectivity to muscarinic ACh receptors.

Front 16

What should be used when a patient has cholinergic poisoning?

Back 16

With cholinergic poisoning, both CNS and PNS toxicity must be reversed. Atropine is extremely useful as an antidote for life-threatening toxicity secondary to nerve gas or insecticides (in both cases, typically an organophosphatase acetylcholinesterase inhibitor)

Front 17

Why are quaternary amine antimuscarinic drugs not used for cholinergic poisoning?

Back 17

Therefore, antimuscarinic agents that are quaternary amines must not be used for this purpose, because they don't distribute to the CNS due to the polar nature secondary to their permanently charged state.

Front 18

What effects do the antimuscarinics have on the eye?

Back 18

-They block M3 receptors in the eye resulting in
1. Cyclopegia (paralysis of the ciliary muscle leading to loss of ability to focus
2. Mydriasis (pupil dilation due to loss of pupillary constrictor muscle activity on the iris)

Front 19

When are cyclopegia and Mydriasis desired?

Back 19

During an ophthalmic exam

Front 20

Name 3 examples of antimuscarinic drugs which are used for the eye examinations?

Back 20

Atropine, Homatropine, and scopolamine

Front 21

What effects do the antimuscarinics have on the cardiovascular system?

Back 21

Blockade of muscarinic (M2) ACh receptors in the heart leads to loss of vagal slowing of the heart rate.
Positive Chronotrophic effect (increase in heart rate)

Front 22

What is the major cardiovasuclar use of atropine?

Back 22

The major use of atropine is for acute treatment of sinus bradycardia, particularily in life-threatening situations such as myocardial infarction.

Front 23

What effects do antimuscarinics have on the respiratory tract?

Back 23

Broncodilation and a reduction in respriatory secretion in patients with airway diseases such as COPD by blockade of M3 postsynaptic receptors.

Front 24

What 2 drugs are used most often for respiratory diseases?

Back 24

Ipratropium and Tiotropium

Front 25

What is commonly used in the management of asthma?

Back 25

Aerosolized delivery of ipratropium, often in conjunction with Albuterol (a beta-adrenergic agonist)

Front 26

What is used for the reduction of bronchial secretions secondary to the use of general anesthetic agents?

Back 26

Ipratropium

Front 27

What effects do the antimuscarinics have on the GI tract?

Back 27

-Secretory activity is supressed, resulting in significant reduction in saliva production leading to dry mouth.
-Gut motility is decreased secoondary to relaxation of GI smooth muscle tissue
-Overall, this has an antidiarrheal effect which may lead to constipation

Front 28

Which two drugs in combination have been used extensively for the treatment of mild to moderate diarrhea?

Back 28

Atropine in combination with Diphenoxylate (an opioid antidiarrheal agent)--> brand name Lomotil. The inclusion of Atropine is mostly for the benefit of preventing abuse of the opioid diphenoxylate.

Front 29

What effects do antimuscarinics have in the Gentitourinary Tract?

Back 29

-Antagonism of M3 ACh receptors results in:
1. relaxation of smooth muscle in the urinary bladder and
2. Ureter contraction of the urinary sphincter.
-Overall, this leads to decrease in urinary bladder urgency and voiding frequency, improvement of urinary incontinence, and an increase in urinary retention.

Front 30

The effects of antimuscarinics on the Gentitourinary tract are useful for the management of?

Back 30

Mild to moderate urinary bladder spasm secondary to surgery, inflammation, or other neurologic conditions, such as neurogenic bladder (often referred to as overactive bladder)

Front 31

Name the 5 antimuscarinic drugs useful for an overactive bladder.

Back 31

Oxybutynin, Tolterodine, darifenacin, solifenacin, and trospium chloride.

Front 32

Which antimuscarinic drug is selective for M3 receptors, why is this impt.?

Back 32

Darifenacin is selective for M3 receptors, and therefore may have less antimuscarinic-related adverse effects due to lack of blockade of other muscarinic receptor subtypes.

Front 33

What effects do the antimuscarinics have on the CNS at usual doses?

Back 33

-At usual doses, antimuscarinic agents (tertiary amines ONLY) have long-lasting sedative effects in the CNS, causing drowsiness and somnolence.

Front 34

What effects do the antimuscarinics have on the CNS at high and toxic doses?

Back 34

Antimuscarinic drugs (tertiary ONLY), may cause tremor, delirium, and hallucinations

Front 35

What are the symptoms of Parkinson's disease attributed to? What is one way to manage this disease?

Back 35

The symptoms of Parkinson's disease are due, in part, to an excess of ACh activity relative to dopamine activity in the CNS.
-One way to manage this disease is to use centrally-acting antimuscarinic agents to decrease ACh activity.

Front 36

What antimuscarinic drug has been used for the management of Parkinson's disease?

Back 36

Benzotropine

Front 37

What is the old saying regarding typical antimuscarinic side effects, that summerizes the major adverse effects?

Back 37

Dry as a bone, blind as a bat, red as a beet, mad as a hatter. This saying is referring to the adverse effects of dry mouth, cyclopegia, hot and flushed skin, and the delirium and hallucinations that accompany large doses of antimuscarinic drugs.

Front 38

Name 6 typical antimuscarinic adverse effects:

Back 38

dry mouth, urinary retention, erectile dysfunction, constipation, and sedation

Front 39

TRUE/FALSE. Use of the antimuscarinic agents needs to be carefully considered in patients for which of the adverse effects may exacerbate existing disease states.

Back 39

TRUE. For example: antimuscarinic-induced urinary retention would make symptoms of prostatic hypertrophy worse.

Front 40

The use of antimuscarinic should be carefully considered in? Why?

Back 40

Pediatric and geriatric populations.

Front 41

Why should antimuscarinics be carefully considered in pediatric patients

Back 41

Mainly for the increased sensitivity in children to antimuscarinic-induced hyperthermia

Front 42

Why should antimuscarinics be carefully considered in geriatric patients?

Back 42

Mainly for the increased sensitivity in geriatrics to constipation and genitourinary adverse effects.

Front 43

What may be given if anitmuscarinic poisoning occurs?

Back 43

In severe cases, the use of a AChE inhibitor, such as physotigmine or neostigmine.

Front 44

What drug interaction could occur with antimuscarinics?

Back 44

Medications that also have significant anticholinergic effects. For example, Amitriptyline, a tricyclic antidepressant with anticholinergic adverse effects, would be expected to add to dry mouht, constipation, and genitourinary adverse effetcs that a patient is experiencing from an antimuscarinic drug.

Front 45

Name 12 antimuscarinic drugs.

Back 45

Atropine, benztropine, darfenacin, dicyclomine, Homatropine, Ipratropium, Oxybutynin, Scopolamine, Solifenacin, Tiotropium, Tolterodine, and Trospium Chloride
"T SAID BOTH STD"