Serotonin Syndrome

Serotonin Syndrome

Combination of 2 agents that affect serotonin transmission

• Activity at 5HT1A and/or 5 HT2A receptors

Highest frequency of SS

• MAOIs (Selegine)

High frequency of SS

• SSRI (Fluoxetine) 

• SNRI (Vortioxetine)

• Clomipramine

Adjunctive risk frequency of SS

• Busprione

• Dextromethorphan

• Lithium

• Select opions (Fentanyl, Meperidine)

• Linezolid

• Stimulants

• Tramadol

Questionable frequency of SS

• Triptans

  • Serotonin agonist but on different serotonin receptors

SS Symptoms: Autonomic Instability

• Diaphoresis

• Hyperthermia

SS Symptoms: Neuromuscular Hyperactivity

• Myoclonus

• Rigidity

• Tremors

• Incoordination

SS Symptoms: Altered mental status

• Agitation

• Confusion

• Hypomaniac

SS Severity: Mild

• Altered mental status (agitation, confusion, mania)

• Autonomic dysfunction (diaphoresis, diarrhea, fever, shivering, labile blood pressure)

• Neuromuscular abnormalities (clonus, hyperreflexia, myoclonus, tremor)

• May also present with mild HTN, tachycardia and mydriasis

SS Severity: Moderate

• The above, plus:

• Temp >40oC (104oF)

• Hyperactive bowel sounds

• Ocular clonus

• Agitation

• Pressured speech 

SS Severity: Severe

• Temp> 41* C (105.8oF)

• Dramatic changes in blood pressure

• Labile heart rate

• Delirium

• Muscle rigidity

SS Tx: Mild

Setting: Observe for at least 6 hours

• Discontinue causative agents

• Supportive Care (hydration, cooling measures, stabilize vital signs)

• Agitation, mild HTN, fever and tachycardia: benzodiazepines maybe

SS Tx: Moderate

Setting: Admit to hospital (cardiac monitoring and observation)

• Asper mild severity, plus:

• Supportive measures: IV hydration, maintain O2 saturation, correct autonomic instability

• Severe agitation and hyperthermia: cyproheptadine

• Avoid physical restraints 

SS Tx: Severe

Setting: Admit to Intensive Care Unit: Ventilator, sedated, and intubated

• As per mild and moderate severity, plus:

• Severe HTN/tachycardia: esmolol, nitroprusside

• Sedation and paralysis with a non-depolarizing agent + intubation/ventilation

First Line Tx for Tx-Resistant Depression

• Quetiapine

• Risperidone

Second Line Tx for Tx-Resistant Depression

• Bupropion

• Lithum

• Mirtazapine

Third Line Tx for Tx-Resistant Depression

• Other antidepressants

• Other stimulants

• TCAs

Experimental Tx for Tx-Resistant Depression

• Ketamine