Anticholinergic Drugs

Question 1

Name the 2 anticholinergic drugs and give basic differences between them.

Answer 1

Atropine (faster onset, shorter peak, shorter duration)

Glycopyrrolate (slower onset, longer peak, longer duration)

Question 2

What is another name for anticholinergic drugs?

Answer 2

Parasympatholytic Drugs

Question 3

What is the mechanism for atropine/glycopyrrolate?

Answer 3

atropine/glycopyrrolate is an anticholinergic. As such, it blocks acetylcholine from bonding with the muscarinic receptors (at the target organs) in the parasympathetic nervous system. Therefore, it inhibits the parasympathetic (calming) effects, encouraging more sympathetic nervous system effects (more flight or fight, increased heart rate).

Question 4

What effect does atropine/glycopyrrolate have on the central nervous system?

Answer 4

+ effects: minimal effect

- effects: n/a

Question 5

What effect does atropine/glycopyrrolate have on the cardiovascular system?

Answer 5

+ effects:
+prevents bradycardia (increases heart rate in animals that have bradycardia)

• effects:
• cardiac arrhythmia (therefore contraindicated in animals with cardiac disease or elevated heart rate)
• temporary bradycardia (atropine)

Question 6

What effect does atropine/glycopyrrolate have on the mucus/secretions?

Answer 6

+ effects:
+ in dogs, decreases secretions/excess salivation

• effects:
• in cats and ruminants, can cause thickened respiratory secretions that may lead to airway blockage (therefore contraindicated in cats and ruminants)

Question 7

What effect does atropine/glycopyrrolate have on the eyes?

Answer 7

+ effects:
None

• effects:
• mydriasis (pupil dilation)
• corneal drying

Question 8

What effect does atropine/glycopyrrolate have on the respiratory system?

Answer 8

+ effects:
+ bronchodilation

• effects:
• none

Question 9

What effect does atropine/glycopyrrolate have on the GI system?

Answer 9

+ effects:
+ none

• effects:
• intestinal peristalsis inhibition (therefore contraindicated in horses, b/c may lead to colic, and ruminants, b/c may lead to bloat)

Question 10

What are the differences in effects between atropine and glycopyrrolate?

Answer 10

They have mostly similar effects. The main difference in duration. Atropine has a faster onset, shorter peak, and shorter duration. Glycopyrrolate has a slower onset, longer peak, and longer duration. The only other difference is that atropine can cause a temporary bradycardia when given, whereas glycopyrrolate does not.