Neuroleptic malignant syndrome

Question 1

What are neuroleptic drugs also known as ?

Answer 1

Anti-psychotics

Question 2

What is neurleptic malignant syndrome?

Answer 2

A rare but potentially life-threatening reaction to anti-psychotics (neuroleptics)

Question 3

What is the underlying pathological abnormality which causes neuroleptic malignant syndrome ?

Answer 3

Central D2 receptor blockade or dopamine depletion in the hypothalamus and nigrostriatal/spinal pathways.

Question 4

What are the signs and symptoms of neuroleptic malignant syndrome ?

Answer 4

• Patients may report dyspnoea (due to hypoventilation caused by muscle rigidity), dysphagia or difficulty walking with the development of a shuffling gait.
• There may be increasing tremor or involuntary movements.
• Rarely, there may be oculogyric crises, opisthotonos, seizures or chorea.
• NMS is most common after initiation or increase in dosage of neuroleptic therapy and in 90% of cases this occurs within 10 days
• There will be hyperthermia with temperature above 38°C.
• Muscular rigidity (lead-pipe type) will always be present.
• There is likely to be an alteration in mental status with confusion or agitation and altered consciousness.
• Autonomic instability may manifest as pallor, tachycardia, fluctuating blood pressure, excessive sweating/salivation, tremor and incontinence.

Question 5

What is the management of neuroleptic malignant syndrome ?

Answer 5

• Airway and breathing need to be protected if there is evidence of compromise.
• Agitated patients require intravenous (IV) benzodiazepines. Physical restraint is best avoided or minimised, as it can worsen the hyperthermia.
• The offending drug should be discontinued - and don’t start any new anti-psychotics, hence if agitation then haloperidol not first line
• IV fluids should be given for dehydration.
• Cooling devices and antipyretics are used to treat hyperthermia.
• If rhabdomyolysis and acute kidney injury occur then alkalinisation of urine and dialysis are often required.
• Dopaminergic drugs (dopamine agonists), such as bromocriptine and amantadine and muscle relaxants, such as dantrolene sodium, used
• Electroconvulsive therapy (ECT) is sometimes used if medication fails to improve the condition