Haldol

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 is also utilized for the control of tics and vocal utterances in Tourette’s syndrome. As a potent dopamine D2 receptor antagonist, it exerts its therapeutic effects by blocking dopamine receptors in the mesolimbic pathway of the brain, thereby reducing positive symptoms of psychosis such as hallucinations, delusions, and disorganized thinking. Its long history of clinical use, established efficacy in acute agitation, and availability in multiple formulations make it a cornerstone in psychiatric pharmacotherapy, particularly in inpatient and emergency settings where rapid tranquilization is required.

Features

• Active ingredient: Haloperidol
• Available formulations: Oral tablets, oral concentrate, short-acting intramuscular injection, long-acting depot injection (decanoate)
• Standard tablet strengths: 0.5 mg, 1 mg, 2 mg, 5 mg, 10 mg, 20 mg
• Depot injection: 50 mg/mL and 100 mg/mL formulations
• Chemical class: Butyrophenone derivative
• Receptor affinity: High potency dopamine D2 receptor antagonist with additional adrenergic and histaminic blocking properties
• Half-life: Approximately 14-36 hours (oral); 3 weeks (decanoate formulation)
• Metabolism: Hepatic via CYP3A4 and glucuronidation
• Bioavailability: 60-70% (oral); 100% (IM)

Benefits

• Rapid reduction of acute psychotic symptoms and agitation within hours of administration
• Effective management of positive symptoms of schizophrenia including hallucinations and delusions
• Long-acting depot formulation provides sustained symptom control and improves medication adherence
• Proven efficacy in treatment-resistant cases and emergency psychiatric situations
• Cost-effective option compared to many newer antipsychotic medications
• Well-established safety profile with extensive clinical experience spanning decades

Common use

Haldol is primarily prescribed for the treatment of schizophrenia and related psychotic disorders. It is particularly effective in managing the positive symptoms of psychosis, including hallucinations, delusions, and thought disorder. The medication is also FDA-approved for controlling tics and vocal utterances in patients with Tourette’s disorder. Off-label uses include management of behavioral disturbances in dementia (with caution due to black box warning), acute agitation in emergency settings, and as an antiemetic in palliative care. The intramuscular formulation is frequently employed in hospital emergency departments for rapid tranquilization of acutely agitated patients, while the decanoate formulation is used for maintenance therapy in chronic psychotic conditions to prevent relapse.

Dosage and direction

Dosage must be individualized based on severity of symptoms, patient response, and tolerability. For psychosis in adults: initial oral dose typically ranges from 0.5-5 mg twice or three times daily, with maintenance doses usually between 5-20 mg daily (maximum 100 mg daily in divided doses). For acute agitation: IM doses of 2-5 mg may be administered every 4-8 hours as needed. Haldol Decanoate: initial dose is 10-15 times the previous daily oral dose, administered IM every 4 weeks (not to exceed 100 mg initially). Oral concentrate should be diluted with water, juice, or carbonated beverages before administration. Tablets may be taken with or without food. Dosage adjustments are necessary in elderly patients, those with hepatic impairment, and when co-administered with CYP3A4 inhibitors.

Precautions

Patients should be monitored regularly for extrapyramidal symptoms (EPS), tardive dyskinesia, and neuroleptic malignant syndrome. Regular assessment of electrolyte levels, complete blood count, and liver function tests is recommended during prolonged therapy. Caution is advised when operating machinery or driving until response to medication is established. Orthostatic hypotension may occur, particularly during initial dose titration. Abrupt discontinuation should be avoided; gradual tapering is recommended to prevent withdrawal symptoms or rebound psychosis. Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at increased risk of death; Haldol is not approved for this use. Temperature regulation may be impaired; patients should avoid overheating and dehydration.

Contraindications

Haldol is contraindicated in patients with known hypersensitivity to haloperidol or any component of the formulation. It should not be used in patients with severe central nervous system depression or comatose states. Contraindicated in patients with Parkinson’s disease or dementia with Lewy bodies due to extreme sensitivity to extrapyramidal effects. Avoid use in patients with known prolonged QT syndrome, recent myocardial infarction, or uncompensated heart failure. Concomitant use with other QT-prolonging agents is generally contraindicated. Not recommended during pregnancy unless potential benefit justifies potential risk to the fetus. Should not be administered to patients experiencing blood dyscrasias or severe hepatic impairment.

Possible side effect

Common side effects include extrapyramidal symptoms (dystonia, akathisia, parkinsonism), sedation, dry mouth, blurred vision, and constipation. Less frequent adverse reactions include weight gain, hyperprolactinemia, galactorrhea, and sexual dysfunction. Serious side effects requiring immediate medical attention include tardive dyskinesia (potentially irreversible involuntary movements), neuroleptic malignant syndrome (hyperthermia, muscle rigidity, autonomic instability), seizures, significant QT prolongation, and severe orthostatic hypotension. Ocular changes including cataracts and corneal opacities have been reported with long-term use. Hematological effects such as leukopenia and agranulocytosis may occur rarely. Dermatological reactions including photosensitivity and skin pigmentation changes have been observed.

Drug interaction

Haldol demonstrates significant interactions with CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) which may increase haloperidol concentrations and toxicity. Concomitant use with other central nervous system depressants (alcohol, benzodiazepines, opioids) may potentiate sedation and respiratory depression. Anticholinergic agents may reduce haloperidol efficacy while increasing anticholinergic side effects. Lithium may increase neurotoxicity risk. Concurrent use with other QT-prolonging agents (antiarrhythmics, certain antibiotics, antidepressants) may increase arrhythmia risk. Carbamazepine and other CYP3A4 inducers may decrease haloperidol concentrations. Levodopa and dopamine agonists may have reduced efficacy when administered with Haldol. Caution is advised with antihypertensive agents due to potential additive hypotensive effects.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is almost time for the next scheduled dose. In that case, the missed dose should be skipped and the regular dosing schedule resumed. Double doses should not be taken to make up for a missed dose. For patients using the depot formulation, contact the healthcare provider if an injection is missed to determine the appropriate course of action. Consistent dosing is important for maintaining therapeutic effects, particularly in maintenance therapy for chronic conditions. Patients should not discontinue medication abruptly without medical supervision due to risk of withdrawal symptoms or relapse of psychotic symptoms.

Overdose

Symptoms of overdose may include severe extrapyramidal reactions, hypotension, sedation, coma, and respiratory depression. Cardiac effects may include QT prolongation, torsades de pointes, and arrhythmias. Seizures and neuroleptic malignant syndrome-like symptoms may occur. Management is primarily supportive and symptomatic: maintain airway, ensure adequate ventilation, and monitor cardiac function continuously. Gastric lavage may be considered if presentation is early. Activated charcoal may be administered if patient presents within 1-2 hours of ingestion. There is no specific antidote; severe extrapyramidal symptoms may respond to anticholinergic agents such as benztropine. Hypotension should be treated with intravenous fluids and vasopressors if necessary. ECG monitoring should continue for at least 24 hours after overdose due to risk of delayed cardiac effects.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in a tight, light-resistant container. Keep oral concentrate in the original container and protect from light. Do not freeze. Keep all medications out of reach of children and pets. Do not store in bathroom areas where moisture could affect stability. Unused portions of oral concentrate should be discarded after the expiration date. Depot injection vials should be stored upright and protected from light. Do not use if solution is discolored or contains particulate matter. Properly dispose of unused medication through take-back programs or according to FDA guidelines.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Individual response to medication may vary. Haldol should only be used under the supervision of a qualified healthcare professional who can monitor for efficacy and adverse effects. The prescriber should be familiar with the complete prescribing information including boxed warnings. Patients should not make changes to their medication regimen without consulting their healthcare provider. This information is not exhaustive and does not replace professional medical judgment.

Reviews

Clinical studies and decades of use demonstrate Haldol’s efficacy in managing acute psychosis and agitation. Systematic reviews confirm its superiority to placebo in schizophrenia treatment with effect sizes of approximately 0.75. The Cochrane Database notes its continued relevance despite newer alternatives, particularly in treatment-resistant cases. Many psychiatrists value its rapid action in emergency settings and the option of long-acting formulation for non-adherent patients. However, reviews consistently note its higher incidence of extrapyramidal side effects compared to second-generation antipsychotics. Patient reviews often mention effectiveness for symptom control but express concerns about side effect burden. The medication maintains a important position in treatment algorithms despite the development of newer agents.