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Haldol Side Effects

Generic Name: haloperidol

Note: This page contains information about the side effects of haloperidol. Some of the dosage forms included on this document may not apply to the brand name Haldol.

For the Consumer

Applies to haloperidol: oral solution, oral tablet

In addition to its needed effects, some unwanted effects may be caused by haloperidol (the active ingredient contained in Haldol). In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking haloperidol:

More common:
  • Difficulty with speaking or swallowing
  • inability to move the eyes
  • loss of balance control
  • mask-like face
  • muscle spasms, especially of the neck and back
  • restlessness or need to keep moving (severe)
  • shuffling walk
  • stiffness of the arms and legs
  • trembling and shaking of the fingers and hands
  • twisting movements of the body
  • weakness of the arms and legs
Less common:
  • Decreased thirst
  • difficulty in urination
  • dizziness, lightheadedness, or fainting
  • hallucinations (seeing or hearing things that are not there)
  • lip smacking or puckering
  • puffing of the cheeks
  • rapid or worm-like movements of the tongue
  • skin rash
  • uncontrolled chewing movements
  • uncontrolled movements of the arms and legs
  • Confusion
  • convulsions (seizures)
  • difficult or fast breathing
  • fast heartbeat or irregular pulse
  • fever (high)
  • high or low blood pressure
  • hot, dry skin, or lack of sweating
  • increased blinking or spasms of the eyelid
  • increased sweating
  • loss of bladder control
  • muscle stiffness (severe)
  • muscle weakness
  • sore throat and fever
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unusual bleeding or bruising
  • unusual facial expressions or body positions
  • unusual tiredness or weakness
  • unusually pale skin
  • yellow eyes or skin
Incidence not known:
  • Continuing nausea or vomiting
  • increase in the frequency of seizures
  • loss of appetite
  • swelling of the face
  • tiredness and weakness

If any of the following symptoms of overdose occur while taking haloperidol, get emergency help immediately:

Symptoms of overdose:
  • Difficulty with breathing (severe)
  • dizziness (severe)
  • drowsiness (severe)
  • muscle trembling, jerking, stiffness, or uncontrolled movements (severe)
  • unusual tiredness or weakness (severe)

Minor Side Effects

Some of the side effects that can occur with haloperidol may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Blurred vision
  • changes in menstrual period
  • constipation
  • dryness of the mouth
  • swelling or pain in the breasts (in females)
  • unusual secretion of milk
  • weight gain
Less common:
  • Decreased sexual ability
  • drowsiness
  • increased sensitivity of the skin to sun (skin rash, itching, redness or other discoloration of skin, or severe sunburn)
  • nausea or vomiting

For Healthcare Professionals

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


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]

Very common (10% or more): Extrapyramidal disorder (up to 34%), hyperkinesia (up to 13%), headache (up to 12%)
Common (1% to 10%): Tardive dyskinesia, dystonia, dyskinesia, akathisia, bradykinesia, hypertonia, somnolence, masked facies, tremor, dizziness, parkinsonism/parkinsonian effects
Uncommon (0.1% to 1%): Convulsion, akinesia, cogwheel rigidity, sedation, involuntary muscle contractions, gait disturbance, persistent tardive dyskinesia
Rare (0.01% to 0.1%): Motor dysfunction, neuroleptic malignant syndrome, nystagmus
Frequency not reported: Drowsiness, epileptic/grand mal seizure, vertigo, lethargy
Postmarketing reports: Opisthotonos[Ref]


Very common (10% or more): Insomnia (up to 19%), agitation (up to 15%)
Common (1% to 10%): Depression, psychotic disorder
Uncommon (0.1% to 1%): Confusion, increased/decreased libido, restlessness, hallucinations
Frequency not reported: Apparent exacerbation of psychotic symptoms, anxiety, euphoria, agitation, apprehension, toxic psychosis, catatonic-like behavioral states[Ref]


Common (1% to 10%): Constipation, dry mouth, salivary hypersecretion/hypersalivation, nausea, vomiting
Frequency not reported: Dyspepsia, diarrhea, heartburn, excessive salivation[Ref]


Common (1% to 10%): Urinary retention, erectile dysfunction, sexual dysfunction
Uncommon (0.1% to 1%): Amenorrhea, dysmenorrhea, galactorrhea, breast discomfort/pain
Rare (0.01% to 0.1%): Menorrhagia, menstrual disorder
Frequency not reported: Priapism, oligomenorrhea, mastalgia, breast engorgement, lactation[Ref]


Common (1% to 10%): Orthostatic hypotension, hypotension
Uncommon (0.1% to 1%): Tachycardia, edema
Rare (0.01% to 0.1%): QT prolongation (on ECG)
Frequency not reported: Ventricular fibrillation, Torsade de pointes/polymorphous configuration of Torsade de pointes, ventricular tachycardia, extrasystoles, peripheral edema, venous thromboembolism, deep vein thrombosis, unusual bleeding, heat stroke
Postmarketing reports: Ventricular arrhythmia, cardiac arrest, hypertension[Ref]

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]


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

Common (1% to 10%): Weight increased/decreased
Frequency not reported: Hypoglycemia, hyperglycemia, loss of appetite, anorexia, hyponatremia
Postmarketing reports: Hyperammonemia[Ref]


Common (1% to 10%): Oculogyric crisis, visual disturbance
Uncommon (0.1% to 1%): Blurred vision
Frequency not reported: Cataracts, retinopathy[Ref]


Common (1% to 10%): Rash
Uncommon (0.1% to 1%): Photosensitivity reaction, urticaria, pruritus, hyperhidrosis
Frequency not reported: Exfoliative dermatitis, leukocytoclastic vasculitis, Toxic epidermal necrolysis, Stevens-Johnson syndrome, erythema multiforme, maculopapular/acneiform skin reactions, alopecia[Ref]


Common (1% to 10%): Muscle rigidity
Uncommon (0.1% to 1%): Torticollis, muscle spasms, musculoskeletal stiffness
Rare (0.01% to 0.1%): Trismus, muscle twitching
Postmarketing reports: Rhabdomyolysis[Ref]


Common (1% to 10%): Hyperthermia
Uncommon (0.1% to 1%): Unusual tiredness/weakness
Frequency not reported: Neonatal drug withdrawal syndrome, sudden/unexpected death, face edema, hypothermia[Ref]


Common (1% to 10%): Abnormal liver function test
Uncommon (0.1% to 1%): Hepatitis, jaundice
Frequency not reported: Acute hepatic failure, cholestasis, impaired liver function[Ref]


Common (1% to 10%): Injection site reaction
Frequency not reported: Injection site abscesses, localized erythema/swelling/tender lumps[Ref]


Uncommon (0.1% to 1%): Dyspnea
Rare (0.01% to 0.1%): Bronchospasm
Frequency not reported: Laryngeal edema, laryngospasm, pulmonary embolism, increased respiratory rate/depth, sore throat, bronchopneumonia/lethal bronchopneumonia[Ref]


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]

Uncommon (0.1% to 1%): Leukopenia
Frequency not reported: Agranulocytosis, neutropenia, pancytopenia, thrombocytopenia, unusual bruising, decreased red blood cell counts, anemia, lymphocytosis, monocytosis, lymphomonocytosis[Ref]


Uncommon (0.1% to 1%): Hypersensitivity reactions
Frequency not reported: Anaphylactic reaction[Ref]


Inappropriate antidiuretic hormone secretion occurred with hyponatremia[Ref]

Rare (0.01% to 0.1%): Hyperprolactinemia
Frequency not reported: Inappropriate antidiuretic hormone secretion, gynecomastia[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. "Product Information. Haldol (haloperidol)." McNeil Pharmaceutical, Raritan, NJ.

Not all side effects for Haldol may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.