Neuroleptic malignant syndrome

Definition

• Adverse reaction to medication that blocks dopamine

Clinical Presentation

• Current antipsychotic use
  • Can occur at any time
  • Especially common with first-generation antipsychotics like haloperidol
• FARM: fever, autonomic dysfunction, rigidity, mental status changes
• Hyperthermia
• Autonomic dysfunction
  • Hypertension
  • Tachycardia
  • Tachypnea
  • Sweating
• Rigidity
• Mental status changes
• Compared to serotonin syndrome, NMS is more likely to have:
  • More severe rigidity and hyperthermia
  • Bradyreflexia
  • Less acute onset
  • Normal bowel sounds and pupils

Investigations

• Labs
  • CK will be elevated (rhabdomyolysis)

Management

• Discontinue offending medication
• Supportive therapy
  • IV fluids
  • Antipyretics
  • Cooling blankets
• Dantrolene, sometimes
• D2 agonists like bromocriptine, maybe
• If myoglobinuria: alkaline diuresis

Prognosis

• Mortality is high at 10-20%