Anticholinergic Syndrome

Question 1

Central inhibition of ACh

Answer 1

Agitated (hyperactive) delirium - typically including confusion, restlessness and picking at imaginary objects - which characterises this toxidrome

Question 2

Peripheral inhibition

Answer 2

Variable - hot, dry skin, flushed appearance, mydriasis, tachycardia, decreased bowel sounds and urinary retention

Question 3

Anticholinergic agents

Answer 3

Atropine
Anti-histamine - Diphenhydramine, Doxylamine, Promethazine, Chlorpheniramine, Cyproheptadine
Anti-tussives- Dextromethorphan
Antidepressants- TCAs
Anti-psychotics - Chlorpromazine, Droperidol, Haloperidol, Quetiapine, Olanzapine
Anti-convulsants- Carbamazepine
Anti-emetics/travel sickness - Hyoscine (scopolamine)
Topical ophthalmoplegics - Cyclopentolate, Homatropine
Plants - Deadly nightshade (Atropa belladonna), jimsonweed, mandrake root, lupin beans, Angel’s Trumpet / Datura
Other - Oxybutynin, benztropine, glycopyrrolate

Question 4

Clinical manifestations (mild-mod)

Answer 4

“Hot as a hare”: Fever
“Red as a beet:” Flushed skin
“Blind as a bat”: Mydriasis = dilated
“Dry as a bone”: Dry mouth, dry eyes and decreased sweating
“Mad as a hatter”: Delirium
“Full as a flask” Urinary retention

Question 5

Clinical manifestations (severe)

Answer 5

CNS depression / coma
Seizures
Cardiac conduction abnormalities (QRS widening and increased QT interval)
Circulatory collapse / hypotension
Rhabdomyolysis