Serotonin Toxicity in the Critically Ill

• Serotonin toxicity (aka serotonin syndrome) can easily be overlooked and misdiagnosed in many of our critically ill patients.
• Several common ED medications are associated with serotonin toxicity and include tramadol, linezolid, ondansetron, and metoclopramide.
• Clues to the diagnosis include hyperthermia, increased muscle tone, hyperreflexia, dilated pupils and clonus.  Of these, clonus is the most sensitive and specific sign.
• A few important treatment pearls:
  • Avoid physical restraints
  • Consider cyproheptadine: only available in PO form; initial dose is 12 mg
  • Avoid dopamine for those that need vasopressors
  • Avoid bromocriptine and dantrolene

References

Bienvenu OJ, Neufeld KJ, Needham DM. Treatment of four psychiatric emergencies in the intensive care unit. Crit Care Med 2012; 40:2662-2670.