Neuroleptic Poisoning
Description Diagnostic criteria General and supportive measures Medicine treatment Referral ICD-10 code: T43.5 DESCRIPTION Neuroleptic overdose may cause a depressed level of consciousness, hypotension, tachycardia and cardiac dysrhythmias and seizures. Commonly used neuroleptics include chlorpromazine, haloperidol and phenothiazine anti-emetics (e.g. promethazine). Acute dystonic reactions
Description
Diagnostic criteria
General and supportive measures
Medicine treatment
Referral
ICD-10 code: T43.5
DESCRIPTION
Neuroleptic overdose may cause a depressed level of consciousness, hypotension, tachycardia and cardiac dysrhythmias and seizures. Commonly used neuroleptics include chlorpromazine, haloperidol and phenothiazine anti-emetics (e.g. promethazine).
Acute dystonic reactions/extrapyramidal symptoms are distressing adverse reactions (sustained muscle spasms) occurring after an overdose or during chronic therapy with neuroleptics. A typical dystonic reaction includes hyperextension or hyperflexion of the limbs with abnormal posturing of the trunk. Other extrapyramidal symptoms may occur.
The neuroleptic malignant syndrome is uncommon following an overdose and is an idiosyncratic life threatening reaction, presenting with:
- temperature dysregulation,
- autonomic instability,
- altered mental state,
- diaphoresis,
- musculoskeletal effects (pipe-like rigidity).
DIAGNOSTIC CRITERIA
- Dystonic reactions.
- Other extrapyramidal symptoms.
GENERAL AND SUPPORTIVE MEASURES
- Observe asymptomatic patients for a minimum of 6 hours.
- Admit all symptomatic patients for continuous cardiac monitoring.
- Patients with hyperthermia, muscular rigidity or seizures are more at risk for rhabdomyolysis and subsequent renal failure; test urine for myoglobin (urine test strip for haemoglobin) and serum for creatine kinase and creatinine.
MEDICINE TREATMENT
- Activated charcoal, see: Poisoning, Treatment.
For acute dystonic reactions:
- Biperidin, IV, slow injection.
- If < 1 year of age: 1 mg.
- If 1–6 years of age: 2 mg.
- If 6–10 years of age: 3 mg.
If concomitant significant anticholinergic findings are present, such as fever and dry skin and mucous membranes, a benzodiazepine is preferred.
REFERRAL
- Patients with neuroleptic malignant syndrome.
- Patient with conduction abnormalities (prolonged QT).
- Patients with acute kidney injury.
Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Paediatrics, 2023 Edition
Chapter 18: Poisoning, 18.1 Poisoning, 18.1.8 Neuroleptic Poisoning