Neuroleptic Malignant Syndrome CCC


life-threatening extrapyramidal complication of using neuroleptic drugs


  • ? -> 2 theories
  • neuroleptic-induced alteration of central neuroregulatory mechanisms -> impaired heat dissipation
  • abnormal reaction of predisposed skeletal muscle (like MH)


  • develops over 24-72 hrs
  • hyperthermia
  • rigidity
  • rhabdomyolysis
  • RESP – decreased chest wall compliance, tachypnoea, pulmonary infection
  • NEURO – dyskinesia, dysarthria, parkinsonianism, agitation, stupour, coma, GTC seizures, chorea, babinski, chorea, trismus
  • RENAL – renal faliure
  • CVS – tachycardia, high BP, autonomic dysfunction
  • HAEM – high WCC
  • HEPATIC – increased LFT’s


  • phenothiazines (chlorpromazine, promethazine)
  • butyrophenones (droperidol, haloperidol)
  • thioxanthenes (chlorprothixene)
  • benzamides (sulpiride)
  • clozapine
  • respiradone
  • abrupt ceasing of neuroleptic or PD drugs
  • alcoholics
  • exhaustion
  • dehydration
  • malnutrition

Important differences between serotonin syndrome and neuroleptic malignant syndrome:

(1) NMS is a idiosyncratic reaction after prolonged exposure to neuroleptics or after withdrawal of a dopamine receptor agonist.
(2) NMS usually develops over days or weeks
(3) NMS usually accompanied by hyperthermia, severe muscle rigidity and rhabdomyolysis (not mydriasis, diarrhoea, hyperreflexia, myoclonus)
(4) NMS frequently associated with multi-organ failure



(1) early recognition
(2) withdrawal of precipitents
(3) supportive care


  • airway assessment and securing if not patent (jaw trismus)
  • hyperventilation
  • liberal fluid resuscitation
  • cool
  • cardiovascular support (may require cautious beta-blockade)
  • paralyse -> rigidity will respond to NDNMBS

Electrolytes and Acid-base

  • hypermetabolic syndrome
  • may require bicarbonate therapy if there is documented severe acidosis that is unresponsive to specific treatment

Specific Therapy

  • bromocriptine
  • amantidine
  • dantrolene

Underlying cause

  • stop agents

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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