UMEM Educational Pearls

Title: Serotonin Syndrome (Part 2) - What Causes It?

Category: Neurology

Keywords: serotonin syndrome, SSRI, SNRI, MAOI, TCA (PubMed Search)

Posted: 10/14/2015 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Last month we discussed symptoms of serotonin syndrome and its diagnosis by the Hunter Criteria. Let's move on to what causes serotonin syndrome.

Serotonin Syndrome - What Causes It?

Serotonin syndrome is not an idiopathic drug reaction, but the result of excess serotonin in the nervous system.
It is classically associated with adminstration of two serotonergic agents, but it can occur after initiation of a single agent or increasing the dose of a serotonergic agent in individuals who are particularly sensitive to serotonin.
Although selective serotonin reuptake inhibitors (SSRIs) are most commonly implicated, there are other medications encountered in the Emergency Department that can also play a role in serotonin syndrome.

There are also reports of serotonin syndrome occuring with methadone, trazodone, and metaxalone (Skelaxin).
Serotonin syndrome is often under-recognized if the symptoms are not severe. Thus a thorough medication history is important in its purely clinical diagnosis.

** Stay tuned for the conclusion on management of serotonin syndrome **

Nordstrom K, Vilke GM, Wilson MP. Psychiatric emergencies for clinicians: emergency department management of serotonin syndrome. J Emerg Med 2015 Oct 7 [Epub ahead of print].

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