What is the treatment for Neuroleptic Malignant Syndrome (NMS)?

Treatment of Neuroleptic Malignant Syndrome (NMS)

The immediate treatment for Neuroleptic Malignant Syndrome (NMS) requires discontinuation of the offending antipsychotic medication and implementation of supportive care, with pharmacological interventions such as bromocriptine or dantrolene reserved for more severe cases. 1, 2

Initial Management

• Immediately discontinue all antipsychotic medications upon suspicion of NMS 1, 3
• Provide aggressive supportive care including:
  • Vigilant nursing care 1
  • Rehydration with intravenous fluids 1, 2
  • Cooling measures for hyperthermia 1
  • Anticoagulation to prevent thrombosis 1
  • Physical therapy to prevent complications of immobility 1

Pharmacological Interventions

• For symptomatic management:

  • Benzodiazepines for agitation and muscle rigidity 1, 4
  • Judicious use of anticholinergics for extrapyramidal symptoms 1

• For moderate to severe cases, consider:

  • Bromocriptine (dopamine agonist) to address dopamine blockade 1, 2, 5
  • Dantrolene sodium (muscle relaxant) for severe rigidity and hyperthermia 1, 2, 5

Second-Line Treatment

• Electroconvulsive therapy (ECT) may be considered when pharmacological interventions fail 1

Clinical Recognition and Monitoring

• Monitor for the tetrad of symptoms that characterize NMS:

  • Mental status changes 6
  • Fever (can reach up to 41.1°C) 6
  • Muscle rigidity ("lead pipe" rigidity) 6
  • Autonomic dysfunction (tachycardia, hypertension, tachypnea) 6

• Laboratory monitoring should include:

  • Complete blood count (leukocytosis is common) 6
  • Creatine kinase (often markedly elevated due to rhabdomyolysis) 6
  • Electrolytes, renal function, and liver function tests 6
  • Arterial blood gas (to assess for metabolic acidosis) 6

Differential Diagnosis

• NMS must be differentiated from other conditions with similar presentations:
  • Serotonin syndrome (more rapid onset, hyperreflexia, clonus) 6
  • Malignant hyperthermia (associated with anesthetics) 6
  • Anticholinergic poisoning (dry mucous membranes, mydriasis) 6

Prevention and Risk Factors

• Be vigilant with patients who have risk factors for NMS:
  • Concomitant use of multiple psychotropic medications 6
  • Dehydration 6
  • Physical exhaustion 6
  • Pre-existing organic brain disease 6
  • Use of long-acting depot antipsychotics 6

Post-NMS Management

• After resolution of NMS, careful consideration should be given before reintroducing antipsychotic medications:
  • Allow sufficient recovery time (at least 2 weeks) 4
  • If antipsychotics are necessary, consider using a different class or atypical antipsychotics 4
  • Start with low doses and titrate slowly 4
  • Monitor closely for recurrence of symptoms 4

Prognosis

• Mortality has decreased from 76% in the 1960s to less than 10-15% with early recognition and treatment 6
• Early diagnosis and prompt intervention are critical to reducing morbidity and mortality 3