UMEM Educational Pearls

Title: Serotonin Syndrome (Part 3) - How to Treat It?

Category: Neurology

Keywords: serotonin syndrome, SSRI, cyproheptadine (PubMed Search)

Posted: 11/11/2015 by WanTsu Wendy Chang, MD (Updated: 11/12/2015)
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Last month we discussed causes of serotonin syndrome including common ED medications such as cyclobenzaprine (Flexeril), tramadol (Ultram), metoclopramide (Reglan), and ondansetron (Zofran).

Let’s conclude this series and discuss how to treat serotonin syndrome:

Treatment of serotonin syndrome is mainly supportive.
Discontinuation of all serotonergic agents is crucial, and may be all that's needed in mild cases.
In moderate to severe cases, use benzodiazepines and titrate to patient sedation and normalization of vital signs.
- Avoid droperidol and haloperidol due to their anticholinergic properties that inhibit sweating and dissipation of body heat.
- Caution if using antipsychotics as neuroleptic malignant syndrome can be misdiagnosed as serotonin syndrome.
Severely intoxicated patients may exhibit autonomic instability with large and rapid changes in blood pressure and heart rate.
- This should be managed with short-acting agents, such as esmolol or nicardipine.
Aggressive control of hyperthermia associated with serotonin syndrome can potentially minimize severe complications such as seizures, coma, DIC, and metabolic acidosis.
- There is a limited role for antipyretics as the mechanism is due to muscle tone rather than central thermoregulation.
- In cases of uncontrollable hyperthermia, intubation and paralytics may be required.
Cyproheptadine is an antihistamine with anti-serotonergic properties that should be used if no significant response to supportive measures.
- Adult dosing is 12 mg PO followed by 2 mg every 2 hours if symptomatic. Max 32 mg in 24 hours.
A case series reported the use of dexmedetomidine for the treatment of refractory serotonin syndrome.

This concludes our 3-part series on serotonin syndrome!

References

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].
Rushton WF, Charlton NP. Dexmedetomidine in the treatment of serotonin syndrome. Ann Pharmacother. 2014;48(12):1651-4.

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