Haloperidol and chlorpromazine

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Haloperidol and chlorpromazine (brand names Haldol, Thorazine) — Antipsychotic; First-generation (typical) antipsychotics.

Identification

• Therapeutic class: Antipsychotic.
• Pharmacologic class: First-generation (typical) antipsychotics.

Pharmacology

• Mechanism of action: Strong dopamine D2 blockade; high extrapyramidal risk (haloperidol high potency, chlorpromazine low potency and more sedating).
• Onset / peak / duration: IM and IV faster; long-acting decanoate available (haloperidol).
• Half-life / therapeutic level: Long; level not routine.

Clinical use

• Indications: Acute psychosis and agitation, schizophrenia, severe nausea (chlorpromazine), intractable hiccups.
• Usual dose, route, frequency: PO, IM, or IV; haloperidol decanoate monthly.
• Maximum dose / adjustments: Lower in elderly; QT monitoring with IV haloperidol.

Safety

• Contraindications: Parkinson disease, severe CNS depression, dementia-related psychosis.
• Black box warning: Increased mortality in elderly patients with dementia-related psychosis (and a warning of QT prolongation and torsades with IV haloperidol).
• Interactions: QT-prolonging drugs, CNS depressants, anticholinergics, dopamine agonists.
• Pregnancy / lactation: Use only if clearly needed.
• High-alert: No.

Adverse effects

• Common side effects: Extrapyramidal symptoms, sedation, orthostatic hypotension (chlorpromazine), dry mouth.
• Serious effects to report: Neuroleptic malignant syndrome, tardive dyskinesia, acute dystonia, QT prolongation.
• Antidote / reversal: Benztropine or diphenhydramine for acute dystonia; supportive care for neuroleptic malignant syndrome.

Nursing process

• Assessment before administration: Movement baseline, ECG (IV haloperidol), blood pressure.
• Interventions during therapy: Monitor for extrapyramidal symptoms; have anticholinergic available for dystonia.
• Monitor: Movements, ECG with IV use, blood pressure.
• Evaluation / expected outcome: Reduced agitation or psychosis.

Patient teaching

• Patient teaching: Report muscle stiffness, restlessness, or abnormal movements.
• Notify provider if: High fever with rigidity, involuntary movements, fainting.
• Administration tips: IV haloperidol needs cardiac monitoring; protect chlorpromazine from causing photosensitivity.