Chp 21 Cholinergic-Blocking Drugs

Question 1

Cholinergic-Blocking Drugs

Answer 1

(anticholinergics, parasympatholytics, antimuscarinic drugs) the class of drugs that block or inhibit the actions of acetylcholine in the parasympathetic nervous system.

Question 2

How do Cholinergic-Blocking Drugs work?

Answer 2

compete with ACh for binding at muscarinic receptors in the PSNS. As a result, ACh is unable to bind to the receptor site and cause a cholinergic effect.

Question 3

What are some examples of Cholinergic-Blocking Drugs?

Answer 3

atropine
dicyclomine (Bentyl)
glycopyrrolate (Robinul)
oxybutynin (Ditropan)
scopolamine (Transderm-Scop)
tolterodine (Detrol)

Question 4

What are the cardiovascular effects of Cholinergic-Blocking Drugs?

Answer 4

• Small doses decrease heart rate

- Large doses increase heart rate

Question 5

What are the CNS effects of Cholinergic-Blocking Drugs?

Answer 5

• Small doses decrease muscle rigidity and tremors

- Large doses cause drowsiness, disorientation, and hallucinations

Question 6

What are the effects of Cholinergic-Blocking Drugs on the eyes?

Answer 6

• Dilated pupils (mydriasis)

- Decreased accommodation caused by paralysis of ciliary muscles (cycloplegia)

Question 7

What are the gastrointestinal effects of Cholinergic-Blocking Drugs?

Answer 7

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

Question 8

What are the symptoms of atropine overdose?

Answer 8

flushing, dry skin and mucous membranes, mydriasis, altered mental status, and fever.
More serious effects include sinus tachycardia, urinary retention, hypertension, hallucinations, and cardiovascular collapse.

Question 9

What is used to treat atropine overdose?

Answer 9

activated charcoal is usually given along with supportive therapy

Question 10

What are the genitourinary effects of Cholinergic-Blocking Drugs?

Answer 10

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

Question 11

What are the glandular effects of Cholinergic-Blocking Drugs?

Answer 11

• decreased bronchial secretions, salivation, sweating

Question 12

What are the respiratory effects of Cholinergic-Blocking Drugs?

Answer 12

• decreased bronchial secretions

- dilated bronchial airways

Question 13

What condition of the DNS are Cholinergic-Blocking Drugs used to treat?

Answer 13

• Parkinson’s disease

- Drug-induced extrapyramidal reactions

Question 14

What cardiovascular conditions are Cholinergic-Blocking Drugs used to treat?

Answer 14

-conditions that affect the hearts conduction system

Question 15

What is atropine used to treat?

Answer 15

Used primarily for cardiovascular disorders:

• diagnosis of sinus node dysfuntion
• Symptomatic second degree heart block
• Sever sinus bradycardia with hemodynamic compromise (advanced life support)