Neuroleptic malignant syndrome is a rare, life-threatening reaction to drugs that block dopamine, such as antipsychotics, or to sudden withdrawal of Parkinson medicines. It usually builds over days and causes high fever, severe muscle rigidity, altered mental status and unstable vital signs.
Key symptoms
- High fever and heavy sweating
- Stiff muscles that feel like lead pipes
- Confusion, agitation or reduced responsiveness
- Trouble swallowing, drooling and slurred speech
What you find on exam
- Temperature, often above 38 °C (100.4 °F)
- Generalized lead-pipe rigidity and tremor
- Fast heart rate and swinging blood pressure
- Mental status and Glasgow Coma Scale
Tests
- Creatine kinase (CK), often very high
- Electrolytes, kidney function and urine for myoglobin
- Blood count; white cells often raised
- Rule out infection, serotonin syndrome and heat stroke: cultures, imaging, lumbar puncture as needed
Treatment basics
- Stop the antipsychotic or restart the withdrawn dopamine drug
- Cooling, intravenous fluids and close monitoring, often in the ICU
- Benzodiazepines such as lorazepam for agitation and rigidity
- Dantrolene or bromocriptine in severe cases
- Prevent clots and protect the kidneys; wait at least 2 weeks before a careful rechallenge
Red flags
- Temperature above 40 °C (104 °F)
- Dark urine or falling urine output
- Breathing difficulty or a falling level of consciousness
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Sources: NCCPA PANCE Content Blueprint; NCSBN 2026 NCLEX-RN Test Plan; Open RN, Nursing Pharmacology 2e. Written by Making Synapses. Making Synapses is not affiliated with these organizations.