Haldol (haloperidol) is a first-generation (typical) antipsychotic medication belonging to the butyrophenone class. It is a high-potency antipsychotic agent primarily indicated for the management of manifestations of psychotic disorders, such as schizophrenia. It is also used for the control of tics and vocal utterances in Tourette’s Disorder, and for the treatment of severe behavioral problems in children. Haldol exerts its therapeutic effects through strong antagonism of dopamine D2 receptors in the mesolimbic pathway of the brain, reducing positive symptoms of psychosis like hallucinations, delusions, and disorganized thinking. Its formulation allows for both acute intervention and long-term maintenance therapy, available in oral tablets, oral concentrate, and short-acting and long-acting intramuscular injections, providing flexibility in clinical management across various patient populations and care settings.

Features

• Contains haloperidol as the active pharmaceutical ingredient
• Available in multiple formulations: oral tablets (0.5 mg, 1 mg, 2 mg, 5 mg, 10 mg, 20 mg), oral concentrate (2 mg/mL), and immediate-release intramuscular injection (5 mg/mL with 1.8 mg methylparaben and 0.2 mg propylparaben per mL, and lactic acid for pH adjustment to 3.4±0.2)
• Decanoate formulation (Haldol Decanoate) available as a long-acting intramuscular injection (50 mg/mL or 100 mg/mL in a sesame oil vehicle) for extended dosing intervals
• Exhibits high dopamine D2 receptor affinity and antagonism
• Demonstrates some adrenergic blocking and anticholinergic activity
• Low to negligible histamine H1 receptor blockade compared to low-potency antipsychotics
• Hepatic metabolism primarily via CYP3A4 and CYP2D6 isoenzymes
• Mean elimination half-life of approximately 20 hours for oral administration (range: 10.7–36.7 hours)

Benefits

• Provides rapid control of acute psychotic agitation and hostility through intramuscular administration
• Effectively reduces the frequency and intensity of positive symptoms in schizophrenia, including hallucinations and delusions
• Offers a long-acting injectable option (Decanoate) to enhance adherence and provide stable plasma levels, reducing relapse rates
• Useful in managing Tourette’s Syndrome by suppressing motor and phonic tics
• Can be employed in emergency settings for chemical restraint of severely agitated patients, minimizing physical trauma risk
• Serves as a comparator drug in clinical research due to its well-established efficacy and side effect profile

Common use

Haldol is predominantly prescribed for the treatment of schizophrenia, providing management of both acute episodes and maintenance therapy to prevent relapse. It is utilized in hospital emergency departments and inpatient psychiatric units for the rapid tranquilization of patients exhibiting severe agitation, aggression, or psychosis. In movement disorders, it is indicated for Tourette’s Syndrome in cases where first-line treatments are ineffective or poorly tolerated. Off-label, it is sometimes used to manage nausea and vomiting in palliative care settings, or for delirium in hospitalized patients, particularly when other antiemetics or sedatives are contraindicated or ineffective. Its use in pediatric populations is generally restricted to severe cases of conduct disorder or explosive aggression, under careful specialist supervision.

Dosage and direction

Dosage must be individualized based on severity of symptoms, patient response, and tolerability. For oral administration in adults with psychosis, initial doses typically range from 0.5 mg to 5 mg two or three times daily. Dose may be gradually adjusted upward, with usual effective range between 2 mg and 20 mg daily, though severely ill patients may require up to 100 mg daily. For IM administration (short-acting), initial dose is usually 2 mg to 5 mg, repeatable every 4–8 hours as needed, though total daily IM dose should generally not exceed 20 mg. For Haldol Decanoate, initial dose is 10 to 15 times the previous daily oral dose, administered IM every 4 weeks, not to exceed 100 mg initially; maximum dose should generally not exceed 450 mg monthly. Always administer deep IM gluteal injection; do not administer intravenously. Oral concentrate should be diluted with water, juice, or soda immediately prior to administration; do not mix with caffeine-containing beverages or tannin-rich drinks like tea.

Precautions

Haldol carries a Black Box Warning for increased mortality in elderly patients with dementia-related psychosis. Use with extreme caution in patients with cardiovascular history (QT prolongation, arrhythmia), Parkinson’s disease, seizure disorders, or hepatic impairment. May cause drowsiness; caution patients about operating machinery or driving. Risk of neuroleptic malignant syndrome (NMS) and tardive dyskinesia (TD) requires ongoing assessment. May mask signs of toxicity from other drugs or conditions like intestinal obstruction. Elevations in prolactin levels may occur. Use during pregnancy only if potential benefit justifies potential risk to fetus (Pregnancy Category C). Not recommended during breastfeeding. Periodic monitoring of CBC, LFTs, and ECG (for QTc interval) is advised during prolonged therapy.

Contraindications

Haldol is contraindicated in patients with known hypersensitivity to haloperidol or any component of the formulation. It is contraindicated in patients with severe toxic CNS depression or comatose states. Should not be used in patients with Parkinson’s disease or dementia with Lewy bodies due to extreme sensitivity to extrapyramidal effects. Contraindicated in cases of known QTc prolongation, recent acute myocardial infarction, or uncompensated heart failure. Avoid use with other drugs known to prolong QTc interval. Not recommended in patients with severe hepatic impairment.

Possible side effect

Common side effects include extrapyramidal symptoms (dystonia, akathisia, parkinsonism), sedation, and dry mouth. Serious adverse reactions may include tardive dyskinesia (often irreversible), neuroleptic malignant syndrome (hyperthermia, muscle rigidity, autonomic instability), seizures, orthostatic hypotension, and significant QTc prolongation. Endocrine effects like hyperprolactinemia, galactorrhea, and menstrual irregularities may occur. Others include weight gain, blurred vision, constipation, urinary retention, and temperature dysregulation. Some patients may experience anxiety, insomnia, or depression. Photosensitivity reactions and skin rashes have been reported.

Drug interaction

Haldol interacts significantly with CYP3A4 inhibitors (e.g., ketoconazole, itraconazole) and CYP2D6 inhibitors (e.g., fluoxetine, paroxetine), which can increase haloperidol concentrations and toxicity. Concurrent use with other CNS depressants (alcohol, benzodiazepines, opioids) potentiates sedation and respiratory depression. May enhance hypotensive effects of antihypertensives. Use with other QTc-prolonging agents (antiarrhythmics, macrolides, antidepressants) increases arrhythmia risk. Anticholinergic drugs may exacerbate constipation or heat prostration, but may reduce extrapyramidal symptoms. Lithium co-administration may increase neurotoxicity risk. Levodopa and dopamine agonists may have reduced efficacy.

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, skip the missed dose and resume the regular dosing schedule. Do not double the dose to make up for a missed one. For patients on once-daily dosing, if remembered within 12 hours of the missed time, take the dose; if beyond 12 hours, wait until next day. For those on multiple daily doses, take if within 4 hours of missed time; otherwise, skip. For long-acting Decanoate injections, contact the healthcare provider to reschedule if an appointment is missed.

Overdose

Overdose symptoms include severe extrapyramidal reactions, hypotension, sedation, coma, and respiratory depression. ECG may show QTc prolongation or torsades de pointes. Management is supportive and symptomatic: ensure airway patency, administer activated charcoal if recent oral ingestion, monitor cardiac function continuously. Hypotension should be managed with IV fluids or norepinephrine (avoid epinephrine due to potential paradoxical effect). Severe extrapyramidal symptoms may be treated with anticholinergics like benztropine. There is no specific antidote. Dialysis is not effective due to high protein binding and extensive distribution.

Storage

Store at controlled room temperature, 20°C to 25°C (68°F to 77°F), with excursions permitted between 15°C and 30°C (59°F and 86°F). Protect from light and moisture. Keep oral concentrate in original bottle; do not transfer to other containers. Keep all medications out of reach of children and pets. Do not freeze. For Decanoate injection, store upright; allow to reach room temperature and reconstitute thoroughly before administration. Discard any unused portion of the oral concentrate after 2 months of opening.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and individualized treatment recommendations. Do not initiate, discontinue, or alter dosage of any medication without physician supervision. The content here is not exhaustive; refer to the full FDA-approved prescribing information for complete details, warnings, and precautions.

Reviews

“Haldol remains a cornerstone in acute agitation management in our ER. Its rapid onset via IM route is invaluable, though we monitor closely for EPS.” – Emergency Physician, 12 years experience.

“While effective for positive symptoms, the side effect profile limits long-term use for many of my patients with schizophrenia. We reserve it for treatment-resistant cases or when LAIs are necessary for adherence.” – Psychiatrist, academic medical center.

“The Decanoate formulation has been transformative for maintaining stability in non-adherent patients. The monthly injection provides peace of mind for families and consistent symptom control.” – Community mental health nurse.

“Used it for intractable hiccups post-operatively with good effect. An old drug but still has niche uses beyond psychiatry.” – Palliative care specialist.