Anticholinergics (Atropine, Glycopyrrolate)

Question 1

What do anticholinergics do?

Answer 1

• Blocks action of acetylcholine at the muscarinic receptors of parasympathetic nervous system
• used as treatment for sinus bradycardia, atrioventricular block and sinoatrial arrest.
• will only increase heart rate when bradycardia is due to vagal stimulation
• bradycardua due to hypothermia will not respond
• can cause arrhythmias where initial arrhythmia will get worse for a brief period of time before increase in heart rate is seen

Question 2

What is the anticholinergic drug of choice when it comes to sionartial arrest?

Answer 2

Atropine, as it has a faster onset time compared to glycopyrrolate.

Question 3

Glycopyrrolate

Answer 3

Fewer tendencies to cause severe tachycardia and cardiac arrhythmias compared to atropine

• suppresses salivation more effectively then atropine
• but both drugs can still cause an increase risk of a mucous plug in the endotracheal tube

Question 4

What kind of patients are the only ones needing an anticholinergic in the premedication protocol?

Answer 4

Paediatric patients (less than 12 weeks old) as they rely on heart rate rather than contractility to maintain cardiac output.

Brachycephalic patients and patients undergoing procedures of the head/neck or eye and patients with pre-existing bradycardia