When is Haldol (haloperidol) contraindicated and what medications cannot be co-administered with it?

Contraindications and Drug Interactions for Haloperidol (Haldol)

Haloperidol is contraindicated in patients with severe toxic central nervous system depression, comatose states from any cause, Parkinson's disease, and in individuals who are hypersensitive to this drug. 1

Absolute Contraindications

• Severe toxic central nervous system depression or comatose states from any cause 1
• Hypersensitivity to haloperidol 1
• Parkinson's disease 1
• Patients with baseline prolongation of QTc interval 2
• Patients receiving concomitant medications known to prolong the QTc interval 2
• Patients with a history of torsades de pointes 2
• Concomitant use with monoamine oxidase inhibitors (MAOIs) 2, 1

Relative Contraindications/Use with Caution

• Severe cardiovascular disorders due to risk of transient hypotension and/or precipitation of anginal pain 1
• Patients with history of seizures or EEG abnormalities (haloperidol may lower seizure threshold) 1
• Patients with known allergies or history of allergic reactions to drugs 1
• Patients receiving anticoagulants (potential interference with anticoagulant effects) 1
• Patients with thyrotoxicosis (risk of severe neurotoxicity including rigidity and inability to walk or talk) 1
• Patients with preexisting low white blood cell count or history of drug-induced leukopenia/neutropenia 1
• Elderly patients (increased risk of mortality compared to other antipsychotics) 3
• Dementia-related psychosis (higher mortality risk) 3

Drug Interactions to Avoid

• Monoamine oxidase inhibitors (MAOIs) - contraindicated due to risk of serotonin syndrome 2
• QT-prolonging medications - increased risk of torsades de pointes 2
• Epinephrine - haloperidol may block its vasopressor activity and cause paradoxical further lowering of blood pressure 1
• Rifampin - can decrease haloperidol plasma levels by approximately 70% 1
• CNS depressants including anesthetics, opiates, and alcohol - haloperidol may potentiate their effects 1
• Anticholinergic drugs - may increase intraocular pressure when administered concomitantly with haloperidol 1
• Benzodiazepines - potential for additive sedation and respiratory depression 2

Special Considerations for Specific Patient Populations

• In patients with delirium, haloperidol should not be used for prevention of delirium in ICU patients 2
• Atypical antipsychotics are preferred over haloperidol for elderly patients with dementia due to lower mortality risk 3
• For patients at risk of extrapyramidal symptoms, consider atypical antipsychotics which have a diminished risk compared to haloperidol 2
• In patients with pneumonia or cardiovascular disease, haloperidol is associated with higher mortality compared to other antipsychotics such as risperidone, quetiapine, sulpiride, and chlorpromazine 3

Monitoring Requirements When Using Haloperidol

• Regular monitoring of complete blood count in patients with risk factors for leukopenia/neutropenia 1
• ECG monitoring for QTc prolongation, especially with higher doses 2, 4
• Monitoring for extrapyramidal symptoms, which are common adverse effects 2
• Vigilance for signs of neuroleptic malignant syndrome 1

Alternative Medications to Consider

• For delirium management: dexmedetomidine is preferred over haloperidol for sedation in ICU patients with delirium 2
• For agitation in dementia: atypical antipsychotics such as risperidone, olanzapine, or quetiapine have lower risk of extrapyramidal symptoms 2
• For psychosis in Parkinson's disease: quetiapine is preferred due to lower risk of extrapyramidal symptoms 2

Haloperidol remains widely used despite these contraindications and potential interactions, but careful patient selection and monitoring are essential to minimize adverse outcomes and mortality risk 3, 5.