Contraindications to Haloperidol
Haloperidol is absolutely contraindicated in patients with severe toxic central nervous system depression, comatose states from any cause, hypersensitivity to the drug, and Parkinson's disease. 1, 2
Absolute Contraindications
- Severe CNS depression or comatose states: Haloperidol can further depress CNS function and worsen outcomes in these patients 1, 2
- Hypersensitivity to haloperidol: Previous allergic reactions to the medication contraindicate its use 1, 2
- Parkinson's disease: Haloperidol blocks dopamine receptors and can severely worsen parkinsonian symptoms 1, 2
- Dementia with Lewy bodies: Similar to Parkinson's disease, these patients are extremely sensitive to extrapyramidal side effects 3
Relative Contraindications and High-Risk Conditions
Cardiac Conditions
- QT prolongation: Baseline QTc >500ms or conditions predisposing to QT prolongation 4
- Concurrent use of other QT-prolonging medications: Increases risk of torsades de pointes 4
- History of ventricular arrhythmias: Higher risk of cardiac complications 4
Neurological Conditions
- History of neuroleptic malignant syndrome: Risk of recurrence 4
- History of seizures: May lower seizure threshold 4
Other High-Risk Conditions
- Elderly patients: Higher sensitivity to side effects, requiring lower starting doses and closer monitoring 4
- Hepatic impairment: Impaired drug metabolism increases risk of toxicity 3
- Severe renal impairment: May affect drug clearance 3
- Pregnancy: Use only when benefits clearly outweigh risks due to potential for neonatal extrapyramidal symptoms 4
Cautions When Using Haloperidol
Monitoring Requirements
- ECG monitoring: Recommended when using doses >5mg IV 5
- Telemetry: For high-risk cardiac patients or those receiving cumulative doses ≥100mg 5
- QTc monitoring: Discontinue if QTc >500ms 4
Dose Considerations
- Start low: Particularly in elderly or frail patients (0.25-0.5mg) 3
- Titrate gradually: To minimize risk of extrapyramidal symptoms 3
- Use lowest effective dose for shortest duration: To reduce risk of tardive dyskinesia 4
Management of Common Side Effects
- Extrapyramidal symptoms: Dose reduction is first-line approach rather than adding anticholinergics 4
- Acute dystonia: Treat with diphenhydramine or benzodiazepines 4
- Akathisia: Manage with dose reduction, beta-blockers, or low-dose benzodiazepines 4
- Orthostatic hypotension: Advise patients to change positions slowly 4
By understanding these contraindications and implementing appropriate monitoring and management strategies, clinicians can minimize the risks associated with haloperidol use while effectively treating conditions where it remains a valuable therapeutic option.