Muscarinic Receptor Blocking Agents

Question 1

MOA: Atropine

Answer 1

Competitive antagonist of acetylcholine at muscarinic receptor site

Used for reversal of anti-ChE effects (Edrophonium); txmt of brady, heart block; Crosses BBB, ↑ CNS effects

Question 2

Indications: Atropine

Answer 2

• Bradycardia
• block responses to vagal reflexes induced by surgical manipulation of visceral organs
• when reversing ND - NMB, used with edrophonium to block parasympathomimetic effects
• large doses for the treatment of poisoning by anticholinesterase
  organophosphorus
  insecticides

Question 3

Side Effects: Atropine

Answer 3

Mydriasis, dry mouth, hyperthermia, tachycardia, flushing, blurred vision, urinary retention, constipation, arrhythmias

paradoxical bradycardia with low doses

Question 4

Doses: Atropine

Answer 4

Reversal: 0.01mg/kg

Bolus: 0.4mg or 1mg every 3-5 min (max total dose 3mg)

0.01-0.02 mg/kg IV/IM up to 0.4-0.6 mg

Question 5

Half Life: Atropine

Answer 5

2-3 Hours

Question 6

Glycopyrrolate

Answer 6

?

Question 7

Scopolamine

Answer 7

Centrally acting antagonist at muscarinic receptors

Indications:

• Antisialagogue
• Motion Sickness
• PONV

Side Effects:
Dry mouth, somnolence, mydriasis, and dizziness