Serotonin Syndrome
Serotonin syndrome is a potentially life-threatening reaction caused by excess serotonin in the body — usually from combining serotonergic medications. Symptoms range from mild to fatal.
Table of Contents
Quick Facts
- ICD-10: G25.81
- Common cause: Drug interactions
- Severity: Can be life-threatening
When to Call 911
Call 911 for:
- High fever after starting a new medication
- Severe agitation or confusion
- Muscle rigidity or twitching
- Seizures
- Rapid heart rate and dangerous changes in blood pressure
Symptoms
Mental status
- Agitation, restlessness
- Confusion
Autonomic
- Sweating, fever
- Rapid heart rate
- Diarrhea
- Blood pressure changes
Neuromuscular
- Muscle twitching (clonus, especially of the legs)
- Hyperreflexia
- Tremor
- Muscle rigidity (severe cases)
Common Causative Combinations
- Two SSRIs/SNRIs together
- SSRI/SNRI + MAOI
- SSRI + tramadol, triptans, linezolid, or methylene blue
- SSRI + St. John's wort or recreational drugs (MDMA, cocaine)
- Overdose of any serotonergic agent
Treatment
- Stop all serotonergic medications immediately
- Hospitalization for supportive care
- Cooling for hyperthermia
- Benzodiazepines for agitation and muscle activity
- Cyproheptadine in severe cases
- ICU care for severe presentations
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. If you are experiencing a medical emergency, call your local emergency number immediately.
References
- Mayo Clinic. Serotonin Syndrome.