aka Toxicology Conundrum 025
Think you’re ready for the toxidrome challenge? You’re about to find out…
How this works
The toxidromes included are those most relevant to the differential diagnosis of serotonin toxicity (see Toxicology Conundrum #024). For each toxidrome see if you can describe the classic findings for each of the clinical features listed below – click on the link to show/hide the answer.
Toxidrome challenge
What history of drug exposure is present?
- — 5HT2A or 5HT1A serotonin receptor agonists e.g. citalopram, ecstasy, tramadol, lithium
- — Dopamine antagonists e.g haloperidol, thioridazine
- — Anticholinergic agents e.g. hyoscine, scopolamine, doxylamine
- — Inhalational anesthetics, suxamethonium
What is the usual cadence of the toxidrome?
- — <12h
- — days
- — <12h
- — minutes-24h
What changes in vital signs are expected?
- — increased T, P, R, BP
- — increased T, P, R, BP
- — increased T, P, R, BP
- — increased T, P, R, BP (notice the recurring theme?)
What are the classic pupil findings?
- — mydriasis
- — mydriasis or normal
- — mydriasis
- — normal
What skin findings are classically described?
- — sweaty
- — sweaty and pallor
- — hot, red and dry
- — sweaty and mottled
Are bowel sounds normal, decreased, absent or hyperactive?
- — hyperactive
- — normal
- — decreased or absent
- — decreased
What are the typical alterations in neuromuscular tone?
- — increased, especially lower limbs
- — lead-pipe rigidity
- — normal
- — generalised rigidity
What are the classic changes in deep tendon reflexes?
- — hyperreflexia and clonus
- — bradyreflexia
- — normal
- — hyporeflexia
What mental status changes are typically found?
- — agitation progresses to coma
- — mutism, staring, bradykinesia, coma
- — agitated delirium
- — agitation
Reference
- Murray L, Daly FFS, Little M, and Cadogan M. Chapter 2.5 Serotonin Syndrome; in Toxicology Handbook, Elsevier Australia, 2007. [Google Books Preview]
PDF 
About Chris Nickson
