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Serotonin syndrome - Symptom

Alternative Names

Hyperserotonemia; Serotonergic syndrome

Symptoms:

Symptoms occur within minutes to hours, and may include:

Agitation or restlessness
Diarrhea
Fast heart beat
Hallucinations
Increased body temperature
Loss of coordination
Nausea
Overactive reflexes
Rapid changes in blood pressure
Vomiting

Signs and tests:

The diagnosis is usually made by asking questions about your medical history, including the types of drugs you take.

To be diagnosed with serotonin syndrome, you must have been taking a drug that changes the body's serotonin levels (serotonergic drug) and have at least three of the following signs or symptoms:

Agitation
Diarrhea
Heavy sweating not due to activity
Fever
Mental status changes such as confusion or hypomania
Muscle spasms (myoclonus)
Overactive reflexes (hyperreflexia)
Shivering
Tremor
Uncoordinated movements (ataxia)

Serotonin syndrome is not diagnosed until all other possible causes have been ruled out, including infections, intoxications, metabolic and hormone problems, and drug withdrawal. Some symptoms of serotonin syndrome can mimic those due to an overdose of cocaine, lithium, or an MAOI.

If you have just start taking or increased the dosage of a tranquilizer (neuroleptic drug), other conditions such as neuroleptic malignant syndrome will be considered.

Tests may include:

Blood cultures (to check for infection)
Complete blood count (CBC)
Drug (toxicology) screen
Electrolyte levels
Electrocardiogram (ECG)
Kidney and liver function tests
Thyroid function tests

Reviewed last on: 7/23/2008
Jacob L. Heller, MD, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington, Clinic. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

References

US Food and Drug Administration. FDA Public Health Advisory: Combined Use of 5-Hydroxytryptamine Receptor Agonists (Triptans), Selective Serotonin Reuptake Inhibitors (SSRIs) or Selective Serotonin/Norepinephrine Reuptake Inhibitors (SNRIs) May Result in Life-threatening Serotonin Syndrome. Rockville, MD: Center for Drug Evaluation and Research; July 19, 2006.

Prator BC. Serotonin syndrome. J Neurosci Nurs. 2006 Apr;38(2):102-5.

Ford MD, Clinical Toxicology. 1st ed. Philadelphia, Pa: WB Saunders; 2001:150, 522, 547, 550.

Bilden EF, Walter FG. Antidepressants. In Marx J, ed. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 6th ed. St. Louis, Mo: Mosby; 2006: chap 149.

Sternbach H. The Serotonin Syndrome. Am J Psychiatry. 1991: 148:705.

Parrot AC. Recreational Ecstasy/MDMA, the serotonin syndrome, and serotonergic neurotoxicity. Pharmacol Biochem Behav. 2002 Apr;71(4):837-44. Review.

Depression

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