Haldol (haloperidol) is a first-generation (typical) antipsychotic medication belonging to the butyrophenone class. It is primarily indicated for the management of manifestations of psychotic disorders, including schizophrenia, and for the control of tics and vocal utterances in Tourette’s Syndrome. It is also used in the short-term treatment of severe agitation and hyperexcitability in pediatric populations and for the management of severe behavioral problems in children. Haldol exerts its therapeutic effects through strong antagonism of central dopamine D2 receptors, particularly in the mesolimbic pathway, which is implicated in the positive symptoms of psychosis. Its high potency and long half-life make it a cornerstone in acute and maintenance psychiatric treatment protocols, though its use requires careful monitoring due to a significant side effect profile, particularly extrapyramidal symptoms (EPS).

Features

• Active Ingredient: Haloperidol
• Drug Class: First-generation (typical) antipsychotic, Butyrophenone derivative
• Available Formulations: Oral tablets, oral concentrate solution, short-acting intramuscular (IM) injection, long-acting decanoate (IM) injection
• Receptor Affinity: High affinity dopamine D2 receptor antagonist; also exhibits antagonism at alpha-1 adrenergic receptors and muscarinic receptors
• Bioavailability: Approximately 60-70% orally; 100% via intramuscular injection
• Half-Life: Oral: 18-24 hours; Haloperidol Decanoate: approximately 3 weeks
• Metabolism: Hepatic, primarily via CYP3A4 and to a lesser extent CYP2D6
• Excretion: Primarily renal (urine) and fecal

Benefits

• Provides rapid and effective control of positive psychotic symptoms such as hallucinations, delusions, and thought disorder.
• Offers a long-acting injectable (LAI) formulation (Decanoate) for enhanced adherence and stable plasma levels in maintenance therapy.
• Effective in managing acute agitation and violent behavior in emergency psychiatric settings via IM administration.
• Can reduce the frequency and severity of tics in patients with Tourette’s Syndrome.
• Useful in the management of intractable hiccups, nausea, and vomiting, and as an adjunct in delirium.
• Its established history and low cost make it a widely accessible treatment option within formulary systems.

Common use

Haldol is most commonly prescribed for the treatment of schizophrenia and related psychotic disorders. It is highly effective for managing the “positive” symptoms of psychosis, including hallucinations, delusions, and disorganized thinking. It is also a standard agent for the rapid tranquilization of acutely agitated patients in hospital emergency departments and inpatient psychiatric units. Beyond psychosis, it is FDA-approved for the treatment of Tourette’s Syndrome in children and adults. Off-label, it is frequently used as a first-line pharmacologic intervention for delirium in hospitalized patients, particularly in critical care settings. It is also employed for severe behavioral disturbances in children with conduct disorder or intellectual disabilities, and for the treatment of intractable hiccups and chemotherapy-induced nausea and vomiting.

Dosage and direction

Dosage is highly individualized and must be titrated to the lowest effective dose for each patient.

Schizophrenia (Oral):

• Adults: Initial dose is often 0.5 mg to 5 mg, 2 or 3 times daily. Dosage may be increased gradually, often by 1-2 mg every few days, based on response and tolerance. The usual therapeutic range is 5 mg to 20 mg daily, though some patients with severe symptoms may require higher doses. The daily dosage should be divided into 2 or 3 doses.
• Elderly/Debilitated Patients: Initiate with a lower dose, typically 0.5 mg to 2 mg daily, in divided doses. Increase gradually, if necessary.

Haloperidol Decanoate (Long-Acting Injection):

• This formulation is ONLY for intramuscular (IM) gluteal injection. The initial decanoate dose is generally 10 to 15 times the previous daily oral dose, administered every 4 weeks. The dose and dosing interval must be carefully individualized. Oral antipsychotic therapy should be maintained for several weeks after the first injection until decanoate levels have stabilized.

Agitation (IM Injection - lactate formulation):

• Adults: A usual dose is 2 mg to 5 mg, which may be repeated every 60 minutes, as necessary. Some patients may require up to 10 mg per dose. The frequency of administration should be reduced as soon as possible.

Tourette’s Syndrome (Children 3-12 years, weighing 15-40 kg):

• Initial dose is 0.5 mg to 1.5 mg daily, in divided doses. The dose may be increased by 0.5 mg increments every 5-7 days until a satisfactory response is achieved. The maintenance dose is typically 0.05 mg to 0.075 mg/kg/day.

Direction:

• Oral Tablets/Concentrate: Can be taken with or without food. The oral concentrate must be diluted with water, juice, or a soft drink before administration. Do not mix with caffeine-containing drinks (coffee, tea) or apple juice.
• IM Injection: Administer deep into the upper outer quadrant of the gluteus muscle. Aspirate to avoid intravascular injection.

Precautions

• Neurologic Malignant Syndrome (NMS): A rare but life-threatening reaction characterized by hyperpyrexia, muscle rigidity, altered mental status, and autonomic instability. Discontinue Haldol immediately and initiate intensive medical treatment if NMS is suspected.
• Tardive Dyskinesia (TD): Potentially irreversible, involuntary, dyskinetic movements may develop with chronic treatment. The risk appears highest in elderly patients, especially women. The syndrome can develop after relatively brief treatment periods at low doses. Use the smallest effective dose for the shortest duration to minimize risk.
• QT Prolongation: Haldol is associated with dose-related QT interval prolongation, which can lead to serious ventricular arrhythmias, including Torsades de Pointes. Use with extreme caution in patients with known cardiovascular disease, a history of arrhythmias, or electrolyte imbalance (e.g., hypokalemia, hypomagnesemia). Avoid use with other drugs known to prolong the QT interval. A baseline ECG is recommended.
• Extrapyramidal Symptoms (EPS): High risk of causing parkinsonism, akathisia, dystonia, and oculogyric crises. These are dose-related and often require dose reduction or concomitant administration of an anticholinergic agent (e.g., benztropine).
• Cerebrovascular Adverse Events (CVAE): An increased incidence of CVAEs, including stroke, has been observed in elderly patients with dementia-related psychosis treated with antipsychotic drugs. Haldol is not approved for the treatment of patients with dementia-related psychosis.
• Sedation and Impairment: May impair mental and/or physical abilities, especially during the initial dose-titration period. Caution patients against operating hazardous machinery, including automobiles.
• Hyperprolactinemia: Dopamine blockade can lead to elevated prolactin levels, potentially causing galactorrhea, amenorrhea, gynecomastia, and impotence.

Contraindications

• Known hypersensitivity to haloperidol or any component of the formulation.
• Patients with severe toxic central nervous system depression or comatose states from any cause.
• Patients with Parkinson’s disease or dementia with Lewy bodies (due to extreme sensitivity to EPS).
• Use is contraindicated in conditions where CNS depression is desirable to be avoided.

Possible side effect

• Very Common (>10%): Extrapyramidal symptoms (akathisia, dystonia, parkinsonism), sedation/somnolence.
• Common (1-10%): Insomnia, restlessness, headache, anxiety, dizziness, hyperprolactinemia, blurred vision, constipation, dry mouth, nausea, weight gain.
• Uncommon (0.1-1%): Tardive dyskinesia, hypotension, hypertension, tachycardia, ECG changes (including QT prolongation), rash, urinary retention.
• Rare (<0.1%): Neurologic Malignant Syndrome, leukopenia/neutropenia, agranulocytosis, seizures, jaundice, lens and corneal opacities, retinopathy.
• Other: Neuroleptic-induced deficit syndrome (apathy, emotional blunting).

Drug interaction

• CNS Depressants (e.g., alcohol, benzodiazepines, opioids, sedating antihistamines): Concomitant use can result in additive CNS depression, profound sedation, and respiratory depression.
• QT-Prolonging Agents (e.g., Class Ia & III antiarrhythmics, certain antibiotics like macrolides/fluoroquinolones, antidepressants, other antipsychotics): Concomitant use significantly increases the risk of life-threatening cardiac arrhythmias. Avoid combination if possible.
• Enzyme Inhibitors (e.g., CYP3A4 inhibitors like ketoconazole, itraconazole, clarithromycin; CYP2D6 inhibitors like fluoxetine, paroxetine): May increase haloperidol plasma concentrations, increasing the risk of toxicity and side effects.
• Enzyme Inducers (e.g., CYP3A4 inducers like carbamazepine, rifampin, St. John’s Wort): May decrease haloperidol plasma concentrations, reducing its therapeutic efficacy.
• Anticholinergic Agents (e.g., benztropine, trihexyphenidyl): May be used to treat EPS but can exacerbate constipation, urinary retention, and blurry vision. They may also counteract the antipsychotic efficacy of Haldol to some degree.
• Levodopa and Dopamine Agonists: Haldol may antagonize the effects of these drugs used to treat Parkinson’s disease.

Missed dose

If a dose is missed, it should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule should be resumed. Do not double the next dose to make up for a missed one. For patients on a once-daily regimen, this is particularly important to avoid excessive plasma concentrations.

Overdose

Symptoms: Severe CNS depression (ranging from sedation to coma), hypotension, tachycardia, ECG changes (prolonged QT interval), extrapyramidal symptoms, agitation, restlessness, seizures, and cardiac arrhythmias. Death has been reported. Management: There is no specific antidote. Management is supportive and symptomatic. Ensure a patent airway and assist ventilation if necessary. ECG monitoring is essential for a minimum of 24 hours due to the risk of delayed arrhythmias. Treat hypotension with IV fluids and vasopressors. Manage severe EPS with anticholinergic agents. Gastric lavage may be considered if ingestion was recent. Forced diuresis is not effective. Dialysis is not expected to be beneficial due to high protein binding and large volume of distribution.

Storage

• Store at controlled room temperature, 20°C to 25°C (68°F to 77°F). Protect from light.
• Keep the oral concentrate in the original container. Do not freeze.
• Keep all medications out of the reach of children and pets.

Disclaimer

This information is for educational and informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The author and publisher are not responsible for any specific health or allergy needs that may require medical supervision and are not liable for any damages or negative consequences from any treatment, action, application, or preparation, to any person reading or following the information in this document.

Reviews

• “Haldol remains the gold standard for rapid control of acute agitation in the ER. Its efficacy is undeniable, though the high incidence of akathisia requires careful management with adjuncts like benzodiazepines or benztropine.” – Board-Certified Emergency Psychiatrist
• “As a long-acting injectable, Haloperidol Decanoate is a workhorse for maintenance therapy in non-adherent schizophrenia patients. It provides predictable pharmacokinetics, but we must vigilantly monitor for tardive dyskinesia at every follow-up appointment.” – Clinical Psychiatric Pharmacist
• “While second-generation antipsychotics are often first-line now due to a better EPS profile, Haldol’s potency, low cost, and availability in multiple formulations secure its place in the psychiatric formulary, especially for treatment-resistant cases.” – Consultation-Liaison Psychiatrist
• “The risk of QT prolongation is a significant clinical consideration. We obtain a baseline ECG on all patients starting Haldol and avoid its use in those with pre-existing cardiac risk factors or polypharmacy with other QT-prolonging drugs.” – Cardiologist