Question

Describe the anticholinergic toxidrome - what phrase can you use to remember it ? What 4 classes of drugs can cause it?

Answer 1

Anticholinergic toxidrome includes symptoms like dilated pupils and dry mouth, and is treated by muscarinic agonists like pilocarpine. Drugs causing this condition include muscarinic antagonists, antihistamines, tricyclic antidepressants, and phenothiazines. For atropine poisoning, the correct antidote is a muscarinic agonist.

Step-by-step explanation:

The anticholinergic toxidrome is characterized by symptoms such as dry mouth, dilated pupils, urinary retention, and decreased bowel sounds, commonly remembered by the phrase “Blind as a bat, mad as a hatter, red as a beet, hot as a hare, and dry as a bone.” This toxidrome can occur due to drugs that inhibit the action of acetylcholine on muscarinic receptors. The antidote for atropine or scopolamine poisoning, both anticholinergic agents, is a muscarinic agonist such as pilocarpine, which can reverse the effects by stimulating the muscarinic receptors.

Four classes of drugs that can cause an anticholinergic toxidrome include:

• Muscarinic antagonists (such as atropine and scopolamine from the Atropa genus)
• Some antihistamines (e.g., diphenhydramine)
• Tricyclic antidepressants (e.g., amitriptyline)
• Phenothiazines (e.g., chlorpromazine)

Answering the student's multiple-choice questions:

1. The antidote to atropine poisoning would be c. muscarinic agonist.
2. Drugs that would have anti-anxiety effects are typically psychoactive drugs, including certain classes of pharmaceuticals that interact with the autonomic nervous system.