Haloperidol Side Effects

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

Applies to haloperidol: intramuscular oil, intramuscular solution.

Other dosage forms:

• oral solution, oral tablet

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.

Serious side effects of haloperidol

Along with its needed effects, haloperidol 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

• difficulty swallowing
• fixed position of the eye
• loss of balance control
• mask-like face
• shuffling walk
• slowed movements
• slurred speech
• stiffness of the arms and legs
• tic-like or jerky movements of the head, face, mouth, and neck
• trembling and shaking of the fingers and hands

Less common side effects

Haloperidol®

• slow movement and reflexes

Haloperidol® Decanoate

• absence of or decrease in body movement
• inability to sit still
• need to keep moving
• restlessness

Rare (both)

• blurred vision
• confusion
• difficulty opening the mouth
• dizziness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fainting
• fast, pounding, or irregular heartbeat or pulse
• high fever
• high or low blood pressure
• increased sweating
• lightheadedness
• lockjaw
• loss of bladder control
• muscle spasm, especially of the neck and back
• muscle twitching
• seizures
• severe muscle stiffness
• uncontrolled eye movements
• unusual tiredness or weakness
• unusually pale skin

Incidence not known (both)

• anxiety
• black, tarry stools
• bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, or warmth at the injection site
• chest pain or tightness
• chills
• clay-colored stools
• cold sweats
• continuing nausea or vomiting
• cool, pale skin
• cough
• dark urine
• decrease in the frequency of urination
• deep or fast breathing with dizziness
• depression
• difficulty in passing urine (dribbling)
• drooling
• dry mouth
• eye pain
• false or unusual sense of well-being
• fever with or without chills
• flushed, dry skin
• fruit-like breath odor
• general feeling of illness, tiredness, or weakness
• headache
• hoarseness
• hot, dry skin
• increase in the frequency of seizures
• increased hunger
• increased thirst
• increased urination
• irregular heartbeat, recurrent
• irritability
• itching, skin rash
• lack of sweating
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
• lip smacking or puckering
• loss of appetite
• loss of consciousness
• lower back or side pain
• muscle weakness
• muscle pain or cramps
• muscle trembling or jerking
• nausea
• nervousness
• nightmares
• noisy breathing
• numbness of the feet, hands, and around the mouth
• painful or difficult urination
• pale skin
• pounding in the ears
• puffing of the cheeks
• rapid or worm-like movements of the tongue
• shakiness
• shuffling walk
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• stomach pain
• swelling of the face, ankles, or hands
• swollen glands
• total body jerking
• trouble breathing
• trouble with sleeping
• twisting movements of the body
• uncontrolled chewing movements
• unexplained weight loss
• unpleasant breath odor
• unusual bleeding or bruising
• unusual dullness, tiredness, weakness, or feeling of sluggishness
• vomiting
• vomiting of blood
• weakness of the arms and legs
• yellow eyes or skin

Other side effects of haloperidol

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)

• absent, missed, or irregular menstrual periods
• acne, pimples
• breast discomfort
• cramps
• decreased interest in sexual intercourse
• heavy bleeding
• inability to have or keep an erection
• increased weight
• loss in sexual ability, desire, drive, or performance
• medium to heavy, irregular vaginal bleeding between regular monthly periods, which may require the use of a pad or a tampon
• stopping of menstrual bleeding
• swelling of the breasts or unusual milk production

Incidence not known (both)

• belching
• blindness
• changes in vision
• decreased vision
• difficulty having a bowel movement
• disturbed color perception
• double vision
• drowsiness
• feeling of constant movement of self or surroundings
• fullness or swelling of the breasts
• halos around lights
• heartburn
• increased in sexual ability, desire, drive, or performance
• increased interest in sexual intercourse
• increased sensitivity of the skin to sunlight
• indigestion
• loss of hair
• night blindness
• overbright appearance of lights
• pain or tenderness of the breasts
• painful or prolonged erection of the penis
• redness or other discoloration of the skin
• sensation of spinning
• severe sunburn
• stomach discomfort or upset
• tunnel vision
• weight loss

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

• 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]

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

• 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]

Gastrointestinal

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

Genitourinary

• 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]

Cardiovascular

• 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]

Metabolic

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

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

Ocular

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

Dermatologic

• 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]

Musculoskeletal

• 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]

Other

• 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]

Hepatic

• 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]

Local

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

Respiratory

• 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]

Hematologic

• 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]

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

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

Endocrine

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

Inappropriate antidiuretic hormone secretion occurred with hyponatremia^[Ref]

Frequently asked questions

• What drugs cause tardive dyskinesia?

Further information

Haloperidol 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.

Medical Disclaimer