Serotonin Syndrome

Pt with h/o depression, seizure disorder, bipolar disorder polysubstance abuse presents with sudden onset agitation s/p suicide attempt with SSRI. Reports concomitant onset of xerostomia, palpitations, diarrhea. Recently started SSRI, SNRI, tricyclic antidepressant, and sumatriptan. Additional medications include carbamazepine, valproic acid, lithium, cyclobenzaprine, Zofran, dextromethorphan. Hypertension, tachycardia, fever pupillary dilation, ocular clonus, diaphoresis, tremor, hyperreflexia, clonus on exam.

  • Obtain CBC, CMP, creatinine kinase, PT/PTT/INR, urine drug screen

  • Consider lumbar puncture

  • Obtain EKG, CXR, head CT

  • Treatment

    • Discontinue all serotonergic medications; do not start fentanyl

    • Administer 1L saline bolus

    • Administer lorazepam 2 mg IV and evaluate response

    • Start cyproheptadine 12 mg loading dose and then 4 mg q2h PRN for symptom control

  • T > 41.1C and/or CK > 10,000:

    • Administer vecuronium 0.1 mg/kg and intubate

    • Continue vecuronium 1.2 mcg/kg/min for 24 hours

Notes

  • Medications prescribed for seizure and bipolar disorders may be serotonergic. However, seizure and bipolar disorders do not inherently increase risk for serotonin syndrome.

  • MDMA and PCP intoxication can mimic serotonin syndrome

  • Symptoms typically resolve within 24 hours