Chapter 21 Cholinergic-blocking drugs

Question 1

By blocking the Cholinergic drugs, we are essentially having what type of effects

Answer 1

sympathetic effects
(blocking ACh from binding and having it's cholinergic effects, allows the sympathetic NS to dominate)

Question 2

Give two other names for Cholinergic blockers

Answer 2

• anticholinergics

* parasympatholytics

Question 3

What do cholinergic blockers do?

Answer 3

block the actions of acetylcholine at the muscarinic receptor in the PSNS

Question 4

What happens to ACh when it is released from the stimulated site but then cannot attach to the muscarinic receptor site due to the cholinergic blocker drug?

Answer 4

it will not bind and therefore fails to have it’s cholinergic effect

Question 5

Cholinergic blockers are competitive antagonists, what are they competing with?

Answer 5

ACh

Question 6

Once chilinergic-blockers bind to receptors, what do they inhibit at these receptors?

Answer 6

nerve transmission

Question 7

What do cholinergic blockers block, at which specific receptors, in which specific nervous system?
(answer all three questions)

Answer 7

• block ACh
• at muscarinic receptors
• in PSNS

Question 8

Is the preganglionic fiber short or long?

Is the postganglionic fiber short or long?

Answer 8

• pre= long

* post= short

Question 9

Where is the nicotinic receptor found?

Answer 9

Ganglion

Question 10

At which type of receptor site do cholinergic-blockers have little effect on?
(only in high doses they have partial blocking effects)

Answer 10

Nicotinic receptors

Question 11

Where does the cholinergic -blockers binding to receptors occur mainly?

Answer 11

neuroeffector junction, or where the nerve ending reaches effector organs such as smooth muscle, cardiac muscle and glands

Question 12

What are the drug effects for cholinergic-blockers on the CNS?
small dose: ?
large dose: ?

Answer 12

small dose: decrease muscle rigidity and tremors

Large dose: drowsiness, disorientation, hallucinations

Question 13

What are the drug effects for cholinergic-blockers on the Cardiovascular?
small dose: ?
large dose: ?

Answer 13

small dose: decrease heart rate

large dose: increase heart rate

Question 14

What are the drug effects for cholinergic-blockers on the Respiratory?

Answer 14

decreased bronchial secretions

dilated bronchial airways

Question 15

Since these drugs have little effect at nicotinic receptors, the majority of the site of action takes place at the

Answer 15

heart
respiratory tract
GI tract
Bladder
eye 
exocrine glands

Question 16

These drugs have the opposite effect of cholinergic drugs (ex: so there is blockade of ACh)
true or false?

Answer 16

true

Question 17

List this drugs effects on the eye

Answer 17

• Dilated pupils (mydriasis)

* decreased accommodation caused by paralysis of ciliary muscles (cycloplegia)

Question 18

List the drug effects on the GI

Answer 18

• relax smooth muscle tone of GI tract
• decrease intestinal and gastric secretions
• decrease motility and peristalsis

Question 19

List the drug effects on the genitourinary

bladder

Answer 19

• relaxed detrusor muscle
• increased constriction of internal sphincter
• result: urinary retention

Question 20

drug effects on glandular?

Answer 20

decreased bronchial secretions, salivation, sweating

Question 21

What are the indications for the CNS?
(cholinergic blockers)
(on test)

Answer 21

decreased muscle rigidity and muscle tremors

• Parkinson’s Disease
• Drug-induced extrapyramidal reactions

Question 22

Why do we use these drugs for the cardiovascular system (indications) ?
low dose effect: ?
high dose effect: ?

Answer 22

they can effect the heart’s conduction system
lose dose: slow the HR
high dose: Block inhibitory vagal effects on SA and AV node pacemaker cells (because vagal effect normally reduces HR)
* results in increased (+) HR

Question 23

What is Atropine primarily used for?

Answer 23

CV disorders (normally used when patient is coding (Cardiac Arrest)

Question 24

What are the results to be expected from this drug when used for Respiratory?

Answer 24

• decreased secretion from nose, mouth, pharynx, bronchi
• relaxed smooth muscle in bronchi/bronchioles
• decreased airway resistance
• Bronchodilation

Question 25

Name for things that cholinergic blockers are used to treat

Answer 25

* exercise induced bronchospasms * Chronic bronchitis * Asthma * COPD

Question 26

Blocking the Cholinergic stimulation of the PSNS allows for unopposed action of the ___

Answer 26

SNS (sympathetic NS)

Question 27

When Cholinergics are working on the GI system, rest and digest is happening so there are secretions, contractions in smooth muscle, GI motility and peristalsis. So when a cholinergic-blocker does its job and blocks cholinergic effect, what happens to the GI?

Answer 27

the opposite decrease secretions relaxation of smooth muscle decreased GI motility and peristalsis

Question 28

Name two issues that cholinergic-blockers are used to treat

Answer 28

* IBS (irritable bowel syndrome) | * GI hypersecretory states

Question 29

If cholinergic-blocker drugs interact with antihistamines, phenothiazines, tricyclic antidepressants, or MAOIs, what is the outcome?

Answer 29

it increases the cholinergic effect (does the opposite of what they are meant for)

Question 30

Nursing Implications for cholinergic-blockers. What do we need to know about patient

Answer 30

assess for * allergies * presence of BPH * glaucoma * tachycardia * MI, HF, Hiatal hernia * GI or GU obstruction * baseline assess/ Vital signs

Question 31

When giving opthalmic solutions, what should you do to prevent systemic absorption?

Answer 31

apply pressure to inner canthus

Question 32

What is the antidote from Atropine overdose?

Answer 32

physostigmine

Question 33

Anticholinergics taken by edlerly patients may increase risk for what?

Answer 33

``` heat stroke (emphasis importance of adequate fluid and salt intake) ```

Question 34

therapeutic effects for patients with Parkinson's?

Answer 34

* fewer tremors | * decreased salivation and drooling

Question 35

therapeutic effects for patients with urologic problems?

Answer 35

* improved urinary patterns * less hypermotility * increased time between voiding