In the U.S.—

In Canada—

• Antidyskinetic, Gilles de la Tourette's syndrome
• Antipsychotic

Pimozide ( PIM-oh-zide) is used to treat the symptoms of Tourette's syndrome. It is meant only for patients with severe symptoms who cannot take or have not been helped by other medicine.

Pimozide works in the central nervous system to help control the vocal outbursts and uncontrolled, repeated movements of the body (tics) that interfere with normal life. It will not completely cure the tics, but will help to reduce their number and severity.

Pimozide may also be used for other conditions as determined by your doctor.

This medicine is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For pimozide, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to pimozide, haloperidol, or other medicines used to treat mental illness. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Diet—It is very important that you do not take pimozide with grapefruit juice. Studies have shown that taking pimozide with grapefruit juice may cause heart rhythm problems.

Pregnancy—Studies in rats and rabbits given more than the highest recommended human dose of pimozide have shown fewer pregnancies, slowed development of the fetus, and toxic effects in the mother and fetus.

Breast-feeding—It is not known whether pimozide passes into breast milk.

Children—Children are especially sensitive to the effects of pimozide. This may increase the chance of side effects during treatment. Pimozide usually is not used in children for any condition other than Tourette's syndrome.

Older adults—Constipation, dizziness or fainting, drowsiness, dryness of mouth, and trembling of the hands and fingers, and symptoms of tardive dyskinesia (such as rapid, worm-like movements of the tongue or any other uncontrolled movements of the mouth, tongue, or jaw, and/or arms and legs) may be especially likely to occur in the elderly, who are usually more sensitive than younger adults to the effects of pimozide.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking pimozide, it is especially important that your health care professional know if you are taking any of the following:

• Amoxapine (e.g., Asendin) or
• Antipsychotics (medicine for mental illness) or
• Metoclopramide (e.g., Reglan) or
• Metyrosine (e.g., Demser) or
• Paroxetine (e.g., Paxil) or
• Promethazine (e.g., Phenergan) or
• Rauwolfia alkaloids (deserpidine [e.g., Harmonyl], rauwolfia serpentina [e.g., Raudixin], reserpine [e.g., Serpalan]) or
• Tacrine (e.g., Cognex)—Taking these medicines with pimozide may increase the chance of developing unusual movements

• Amphetamines or
• Methylphenidate (e.g., Ritalin) or
• Pemoline (e.g., Cylert)—These medicines may cause tics and pimozide is not used to treat tics caused by other medicines

• Anticholinergics (medicine for abdominal or stomach spasms or cramps)—Taking these medicines with pimozide may increase the chance of certain side effects, such as dryness of mouth, constipation, and unusual excitement

• Azithromycin (e.g., Zithromax) or
• Clarithromycin (e.g., Biaxin) or
• Dirithromycin (e.g., Dynabac) or
• Disopyramide (e.g., Norpace) or
• Erythromycin (e.g., Erybid) or
• Indinavir (e.g., Crixivan) or
• Itraconazole (e.g., Sporanox) or
• Ketoconazole (e.g., Nizoral) or
• Maprotiline (e.g., Ludiomil) or
• Nefazodone (e.g., Serzone) or
• Nelfinavir (e.g., Viracept) or
• Phenothiazines (chlorpromazine [e.g., Thorazine], fluphenazine [e.g., Prolixin], mesoridazine [e.g., Serentil], methotrimeprazine [e.g., Nozinan], pericyazine [e.g., Neuleptil], perphenazine [e.g., Trilafon], pipotiazine [e.g., Piportil L ₄], prochlorperazine [e.g., Compazine], promazine [e.g., Sparine], thiopropazate [e.g., Dartal], thioproperazine [e.g., Majeptil], thioridazine [e.g., Mellaril], trifluoperazine [e.g., Stelazine], triflupromazine [e.g., Vesprin]) or
• Probucol (e.g., Lorelco) or
• Procainamide (e.g., Pronestyl) or
• Quinidine (e.g., Quinidex) or
• Ritonavir (e.g., Norvir) or
• Saquinavir (e.g., Invirase) or
• Tricyclic antidepressants (amitriptyline [e.g., Elavil], amoxapine [e.g., Asendin], clomipramine [e.g., Anafranil], desipramine [e.g., Pertofrane], doxepin [e.g., Sinequan], imipramine [e.g., Tofranil], nortriptyline [e.g., Aventyl], protriptyline [e.g., Vivactil], trimipramine [e.g., Surmontil])
• Troleandomycin (e.g., Tao) or
• Zileuton (e.g., Zyflo)— Do not take any of these medicines while you are taking pimozide. Taking these medicines with pimozide may increase the chance of developing serious changes in the rhythm of your heart

• Central nervous system (CNS) depressants (medicines that cause drowsiness)—Using these medicines with pimozide may increase the CNS depressant effects

• Breast cancer (history of) or
• Glaucoma, narrow angle or
• Heart disease or
• Intestinal blockage or
• Urinary tract blockage or difficult urination—Pimozide may make the condition worse

• Kidney disease or
• Liver disease—Higher blood levels of pimozide may occur, increasing the chance of side effects

• Low blood potassium—Pimozide may increase the chance of developing serious changes in heart rhythm

• Seizures, history of—Pimozide may increase the chance of having seizures

• Tics other than those caused by Tourette's syndrome—Pimozide should not be used because of the risk of serious side effects

Use pimozide only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

Dosing—

The dose of pimozide will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of pimozide. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using pimozide.

• For oral dosage form (tablets):
  • For Tourette's syndrome:
    • Adults—To start, 1 to 2 milligrams (mg) a day. Your doctor may increase your dose if needed. However, the dose is usually not more than 10 mg a day.
    • Children up to 12 years of age—Dose must be determined by the doctor.
    • Children 12 years of age and older—To start, 0.05 mg per kilogram (0.023 mg per pound) of body weight a day. Your doctor may increase your dose if needed. However, the dose is usually not more than 10 mg a day.

Missed dose—

If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Your doctor should check your progress at regular visits, especially during the first few months of treatment with this medicine. The amount of pimozide you take may be changed often to meet the needs of your condition and to help avoid unwanted effects.

Do not take azithromycin, clarithromycin, dirithromycin, disopyramide, erythromycin, indinavir, itraconazole, ketoconazole, maprotiline, nefazodone, nelfinavir, phenothiazines, probucol, procainamide, quinidine, ritonavir, saquinavir, tricyclic antidepressants, troleandomycin, or zileuton while you are taking pimozide, or you may develop a very serious irregular heartbeat.

Do not suddenly stop taking this medicine without first checking with your doctor. Your doctor may want you to reduce gradually the amount you are taking before stopping completely. This will allow your body time to adjust and help to avoid worsening of your medical condition.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

This medicine may cause some people to become drowsy or less alert or to have blurred vision or muscle stiffness, especially as the amount of medicine is increased. Even if you take pimozide at bedtime, you may feel drowsy or less alert on arising. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to see well or if you do not have good muscle control.

Although not a problem for many patients, dizziness, lightheadedness, or fainting may occur when you get up from a sitting or lying position. Getting up slowly may help. If the problem continues or gets worse, check with your doctor.

Before having any kind of surgery, dental treatment, or emergency treatment, tell the medical doctor or dentist in charge that you are using this medicine. Taking pimozide together with medicines that are used during surgery or dental or emergency treatment may increase the CNS depressant effects.

Pimozide may cause dryness of the mouth. For temporary relief, use sugarless gum or candy, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.

Along with its needed effects, pimozide can sometimes cause serious unwanted effects. Tardive dyskinesia (a movement disorder) may occur and may not go away after you stop using the medicine. Signs of tardive dyskinesia include fine, worm-like movements of the tongue, or other uncontrolled movements of the mouth, tongue, cheeks, jaw, or arms and legs. Other serious but rare side effects, such as abnormal heart rhythm or the neuroleptic malignant syndrome, may also occur. You and your doctor should discuss the good this medicine will do as well as the risks of taking it.

Stop taking pimozide and get emergency help immediately if any of the following side effects occur:

• Rare--Signs of the neuroleptic malignant syndrome (usually two or more occur together)
  • 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) 
  
  

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

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Difficulty in speaking;  dizziness or fainting;  fast or irregular heartbeat;  loss of balance control;  lack of facial expression;  mood or behavior changes;  restlessness or need to keep moving;  shuffling walk;  slowed movements;  stiffness of arms and legs;  swelling or soreness of breasts (less common in males);  trembling and shaking of fingers and hands;  unusual secretion of milk (rare in males) 
  
  

• Less common or rare
  • Difficulty in swallowing;  inability to move eyes;  increased blinking or spasms of eyelid ;  lip smacking or puckering;  menstrual changes;  muscle spasms, especially of the face, neck, or back;  puffing of cheeks;  rapid or worm-like movements of tongue;  skin rash and itching;  sore throat and fever;  swelling of face;  uncontrolled chewing movements;  uncontrolled movements of neck, trunk, arms, or legs, including twisting movements;  unusual bleeding or bruising;  unusual facial expressions or body positions;  yellow eyes or skin 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• 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 mouth;  skin discoloration 
  
  

• Less common
  • Decreased sexual ability;  diarrhea;  headache;  loss of appetite and weight ;  mental depression;  nausea and vomiting;  tiredness or weakness 
  
  

After you stop using pimozide, it may still produce some side effects that need attention. During this period of time, check with your doctor as soon as possible if you notice any of the following side effects:

• Lip smacking or puckering;  puffing of cheeks;  rapid or worm-like movements of the tongue ;  uncontrolled chewing movements;  uncontrolled movements of the arms and legs 

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although this use is not included in product labeling, pimozide is used in certain patients with the following medical condition:

• Psychotic disorders, such as schizophrenia

Other than the above information, there is no additional information relating to proper use, precautions, or side effects for this use.