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Pimozide Side Effects

In Summary

Commonly reported side effects of pimozide include: akathisia, akinesia, sedation, and visual disturbance. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to pimozide: oral tablet

As well as its needed effects, pimozide may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking pimozide, check with your doctor immediately:

More common:
  • Difficulty with speaking
  • dizziness or fainting
  • fast or irregular heartbeat
  • lack of facial expression
  • loss of balance control
  • mood or behavior changes
  • restlessness or need to keep moving
  • shuffling walk
  • slowed movements
  • stiffness of the arms and legs
  • swelling or soreness of the breasts (less common in males)
  • trembling and shaking of the fingers and hands
  • unusual secretion of milk (rare in males)
Less common or rare:
  • Difficulty with swallowing
  • inability to move the eyes
  • increased blinking or spasms of the eyelid
  • lip smacking or puckering
  • menstrual changes
  • muscle spasms, especially of the face, neck, or back
  • puffing of the cheeks
  • rapid or worm-like movements of the tongue
  • skin rash and itching
  • sore throat and fever
  • swelling of the face
  • uncontrolled chewing movements
  • uncontrolled movements of the neck, trunk, arms, or legs, including twisting movements
  • unusual bleeding or bruising
  • unusual facial expressions or body positions
  • yellow eyes or skin
  • Convulsions (seizures)
  • difficult or unusually fast breathing
  • fast heartbeat or irregular pulse
  • fever (high)
  • high or low (irregular) blood pressure
  • increased sweating
  • loss of bladder control
  • muscle stiffness (severe)

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

Symptoms of overdose:
  • Coma
  • dizziness (severe)
  • muscle trembling, jerking, or stiffness (severe)
  • troubled breathing (severe)
  • uncontrolled movements (severe)

Minor Side Effects

Some pimozide side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • Blurred vision or other vision problems
  • constipation
  • dizziness, lightheadedness, or fainting when getting up from a lying or sitting position
  • drowsiness
  • dryness of the mouth
  • skin discoloration
Less common:
  • Decreased sexual ability
  • diarrhea
  • headache
  • loss of appetite and weight
  • mental depression
  • nausea and vomiting
  • tiredness or weakness

For Healthcare Professionals

Applies to pimozide: oral tablet


The most common side effects include somnolence, hyperhidrosis, nocturia, and dizziness.[Ref]

Nervous system

Very common (10% or more): Somnolence (up to 25%), dizziness (up to 11%)
Common (1% to 10%): Extrapyramidal disorder, akathisia, headache, lethargy, tremor, hyperkinesia, limb tremor, torticollis
Uncommon (0.1% to 1%): Bradykinesia, cogwheel rigidity, dyskinesia, dystonia, dysarthria
Frequency not reported: Neuroleptic malignant syndrome, grand mal convulsion, tardive dyskinesia, electroencephalogram abnormal, motor restlessness, hyperreflexia, opisthotonos, drowsiness, sedation, speech disorder, handwriting change, taste change, akinesia, parkinsonism, fainting
Postmarketing reports: Seizure[Ref]

Extrapyramidal symptoms typically occurred during the first few days of treatment and involved mild to moderate Parkinson-like symptoms. This disorder is usually dose-related, with an increased occurrence and severity of symptoms with high doses; symptoms decreased or disappeared with lower doses. While these symptoms were usually reversible, a few cases of persistent symptoms required discontinuation.

Grand mal seizures occurred at doses greater than 20 mg/day.[Ref]


Very common (10% or more): Adverse behavior effect (up to 22.2%)
Common (1% to 10%): Depression, agitation, insomnia, abnormal dreams, restlessness, nervous
Frequency not reported: Libido decreased/lost, excitement[Ref]


Sudden, unexpected deaths have occurred at doses greater than 20 mg/day.[Ref]

Very common (10% or more): Asthenia (up to 13.8%)
Common (1% to 10%): Extreme exhaustion
Uncommon (0.1% to 1%): Face edema
Frequency not reported: Neonatal drug withdrawal syndrome, body temperature dysregulation, hypothermia
Postmarketing reports: Sudden, unexplained death, hyperpyrexia, thirst[Ref]


Very common (10% or more): Hyperhidrosis (up to 13%)
Common (1% to 10%): Sebaceous gland overactivity, rash
Uncommon (less than 1%): Pruritus
Frequency not reported: Urticaria, skin irritation[Ref]


Very common (10% or more): Nocturia (up to 12%)
Common (1% to 10%): Urinary frequency, erectile dysfunction
Uncommon (0.1% to 1%): Amenorrhea
Frequency not reported: Galactorrhea, menstrual disorder, breast secretions, impotence[Ref]


Common (1% to 10%): Constipation, dry mouth, vomiting, increased salivation/salivary hypersecretion, dysphagia
Frequency not reported: Diarrhea, nausea, gastrointestinal distress
Postmarketing reports: Gingival hyperplasia[Ref]

Gingival hyperplasia occurred in animal models at high doses, but was reversible after discontinuation.[Ref]


Common (1% to 10%): Muscle rigidity, myalgia
Uncommon (0.1% to 1%): Muscle spasms
Frequency not reported: Rigidity, neck rigidity, muscle cramps, muscle tightness, stooped posture[Ref]


Common (1% to 10%): Vision blurred, visual disturbance
Uncommon (0.1% to 1%): Oculogyric crisis
Frequency not reported: Sensitivity of eyes to light, decrease accommodation, spots before eyes, periorbital edema, cataracts[Ref]


Hyperglycemia occurred in patients with preexisting diabetes.[Ref]

Common (1% to 10%): Anorexia, weight increased
Frequency not reported: Hyperglycemia, hyponatremia, appetite increase, weight loss[Ref]


Electrocardiographic changes include prolongation of the QT interval, flattening/notching/inversion of the T wave, and the appearance of U waves.[Ref]

Common (1% to 10%): ECG abnormal
Frequency not reported: Torsade de Pointes, ventricular tachycardia/tachycardia, ventricular fibrillation, chest pain, postural hypotension/hypotension, hypertension, palpitations
Postmarketing reports: Cardiac arrest, venous thromboembolism, deep vein thrombosis[Ref]


Frequency not reported: Blood prolactin increases, gynecomastia[Ref]


Frequency not reported: Glycosuria[Ref]


Postmarketing reports: Hemolytic anemia[Ref]


Postmarketing reports: Pulmonary embolism[Ref]


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

2. "Product Information. Orap Tablets (pimozide)." Gate Pharmaceuticals, Sellersville, PA.

It is possible that some side effects of pimozide may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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