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Haldol Side Effects

Generic name: haloperidol

Medically reviewed by Drugs.com. Last updated on Oct 4, 2023.

Note: This document provides detailed information about Haldol Side Effects associated with haloperidol. Some dosage forms listed on this page may not apply specifically to the brand name Haldol.

Applies to haloperidol: intramuscular oil, intramuscular solution.

Other dosage forms:

Important warnings This medicine can cause some serious health issues

Intramuscular route (injectable)

Elderly patients with dementia-related psychosis treated with atypical antipsychotic drugs are at an increased risk of death compared with placebo-treated patients.

Although the causes of death in clinical trials were varied, most of the deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature.

Observational studies suggest that conventional antipsychotic drugs may also increase mortality.

It is unclear from these studies to what extent the mortality findings may be attributed to the antipsychotic drug as opposed to patient characteristics.

Haloperidol decanoate is not approved for the treatment of patients with dementia-related psychosis.

Intramuscular route (solution)

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death compared to placebo.

Although the causes of death in clinical trials were varied, most of the deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature.

Observational studies suggest that antipsychotic drugs may increase mortality.

It is unclear from these studies to what extent the mortality findings may be attributed to the antipsychotic drug as opposed to patient characteristics.

Haloperidol injection is not approved for the treatment of patients with dementia-related psychosis.

Precautions

It is very important that your doctor check your progress while you receive this medicine to allow for changes in your dose and help reduce any unwanted effects.

Do not stop receiving Haldol® suddenly without asking your doctor. You may need to slowly decrease your dose before stopping it completely.

This medicine may cause serious allergic reactions (eg, anaphylaxis, angioedema, dermatitis exfoliative), which can be life-threatening and require immediate medical attention. Tell your doctor right away if you have a cracks in the skin, loss of heat from the body, rash, itching, hoarseness, red, swollen skin, scaly skin, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after receiving this medicine.

Contact your doctor as soon as possible if you have chest pain or discomfort, a fast heartbeat, trouble with breathing, or fever and chills. These may be symptoms of a very serious problem with your heart.

This medicine may cause tardive dyskinesia (a movement disorder). Check with your doctor right away if you have a lip smacking or puckering, puffing of the cheeks, rapid or worm-like movements of the tongue, uncontrolled chewing movements, or uncontrolled movements of the arms and legs.

Check with your doctor right away if you have seizures, difficulty with breathing, a fast heartbeat, a high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin, or tiredness. These could be symptoms of a serious condition called neuroleptic malignant syndrome (NMS).

This medicine will often make you sweat less, causing your body temperature to increase. Use extra care not to become overheated during exercise or hot weather while you are receiving this medicine, since overheating may result in heat stroke. Also, hot baths or saunas may make you feel dizzy or faint while you are receiving this medicine.

This medicine may cause some people to become dizzy, drowsy, or may cause trouble with thinking or controlling body movements, which may lead to falls, fractures or other injuries. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

Dizziness, lightheadedness, or fainting may occur, especially when you get up suddenly from a lying or sitting position. Getting up slowly may help. If this problem continues or gets worse, check with your doctor.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are receiving this medicine.

Haloperidol can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. If you can, avoid people with infections. Check with your doctor right away if you think you are getting an infection, or if you have a fever or chills, a cough or hoarseness, lower back or side pain, or painful or difficult urination.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of Haldol

Along with its needed effects, haloperidol (the active ingredient contained in Haldol) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking haloperidol:

More common side effects

Haloperidol®

  • excessive muscle tone
  • inability to move the eyes
  • increase in body movements
  • increased blinking or spasms of the eyelid
  • muscle stiffness, tension, or tightness
  • sleepiness or unusual drowsiness
  • sticking out of the tongue
  • tremor
  • trouble with breathing, speaking, or swallowing
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unusual facial expressions

Haloperidol® Decanoate

Less common side effects

Haloperidol®

  • slow movement and reflexes

Haloperidol® Decanoate

Rare (both)

Incidence not known (both)

Other side effects of Haldol

Some side effects of haloperidol may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common side effects

Haloperidol®

  • constipation
  • increased watering of the mouth

Rare (both)

Incidence not known (both)

For healthcare professionals

Applies to haloperidol: compounding powder, injectable solution, intramuscular solution, oral concentrate, oral tablet.

General adverse events

The most common side effects include extrapyramidal disorder, insomnia, and agitation.[Ref]

Nervous system

Acute dystonia usually occurred early in treatment.

Sedation may occur more frequently in elderly patients.

Akathisia usually occurred within 6 hours of administration and may be indistinguishable from psychotic agitation.[Ref]

Psychiatric

Gastrointestinal

Genitourinary

Cardiovascular

QT prolongation, Torsade de pointes, ventricular arrhythmias/fibrillation/tachycardia and cardiac arrest occurred more frequently at high doses and/or in patients at risk for cardiovascular side effects.

Tachycardia and hypotension may occur more frequently in elderly patients. Hypotension occurred as a dose-related event.

Heat stroke included hot, dry skin, the inability to sweat, muscle weakness, and/or confusion.[Ref]

Metabolic

Hyperammonemia occurred in a pediatric patient with citrullinemia (inherited disorder of ammonia excretion).[Ref]

Ocular

Dermatologic

Musculoskeletal

Other

Hepatic

Local

Respiratory

Hematologic

Agranulocytosis included sore throat/fever and unusual bleeding/bruising, and typically occurred with concurrent use of other drugs.

Leukopenia and leukocytosis were usually mild and transient.[Ref]

Hypersensitivity

Endocrine

Inappropriate antidiuretic hormone secretion occurred with hyponatremia[Ref]

References

1. (2002) "Product Information. Haldol (haloperidol)." McNeil Pharmaceutical

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

Does Haldol interact with my other drugs?

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Frequently asked questions

Further information

Haldol side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.