SynapsesWhat exactly IS serotonin syndrome?

It’s caused by the excess of serotonin and presents classically as:

  • Altered mental status
  • Autonomic instability
  • Neuromuscular hyperactivity

Fortunately, there’s a nice algorithm (Hunter’s decision rule) which helps you decide whether it is serotonin syndrome or not. I also include a table, which I adapted from the New England Journal of Medicine review article on Serotonin Syndrome, which helps you to differentiate it from its mimickers, such as anticholinergic syndrome, neuroleptic malignant syndrome, and malignant hyperthermia.


Adapted from  1,2
See other Paucis Verbis cards.

A video to remind you what clonus looks like:

Thanks to Dr. Steve MacDade (Univ of Florida, Jacksonville EM resident) for the idea!

1.
Boyer E, Shannon M. The serotonin syndrome. N Engl J Med. 2005;352(11):1112-1120. [PubMed]
2.
Ables A, Nagubilli R. Prevention, recognition, and management of serotonin syndrome. Am Fam Physician. 2010;81(9):1139-1142. [PubMed]
Michelle Lin, MD
ALiEM Editor-in-Chief
Academy Endowed Chair of EM Education
Professor of Clinical Emergency Medicine
University of California, San Francisco
Michelle Lin, MD
Michelle Lin, MD

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