Precautions
Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: blood problems (such as a low white blood cell count), a certain eye condition (glaucoma), dementia, depression, heart problems (such as slow/fast/irregular heartbeat, low blood pressure), slow movement of the gut/intestines (such as chronic constipation, blockage), kidney disease, liver disease, brain disorder/tumor/injury, drug/alcohol/substance abuse, breast cancer, Parkinson’s disease, seizure disorder, a certain severe reaction to other antipsychotic-type medications (neuroleptic malignant syndrome-NMS), difficulty urinating (such as due to prostate problems).
This drug may make you dizzy or drowsy or cause vision changes. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Avoid alcoholic beverages.
Pimozide may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.
The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using pimozide, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/”water pills”) or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using pimozide safely.
Before having surgery or imaging procedures (such as certain X-rays, CT scans) requiring the use of contrast dye (such as metrizamide), tell your doctor or dentist that you are using this medication and about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).
During pregnancy, this medication should be used only when clearly needed. Babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn especially during their first month, tell the doctor right away.
Since untreated mental/mood problems (such as schizophrenia) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy.
It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.
Interactions
Some products that may interact with this drug include: anticholinergic/antispasmodic drugs (such as atropine, dicyclomine, scopolamine), drugs that increase the amount of dopamine in your body (such as bromocriptine, cabergoline, levodopa, pergolide, ropinirole).
Other medications can affect the removal of pimozide from your body, which may affect how pimozide works. Examples include aprepitant, azole antifungals (such as ketoconazole, itraconazole), delavirdine, HIV protease inhibitors (such as ritonavir, nelfinavir), hepatitis C virus protease inhibitors (such as boceprevir, telaprevir), macrolide antibiotics (such as azithromycin, erythromycin), nefazodone, SSRI antidepressants (such as fluvoxamine, paroxetine, sertraline), zileuton, among others.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine).
Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
Many drugs besides pimozide may affect the heart rhythm (QT prolongation). Examples include amiodarone, cisapride, citalopram/escitalopram, chlorpromazine, dofetilide, procainamide, quinidine, ranolazine, sotalol, macrolide antibiotics (such as clarithromycin, erythromycin), among others.
Also report the use of drugs that might increase seizure risk when combined with pimozide, such as bupropion, isoniazid (INH), phenothiazines (such as promethazine), lithium, theophylline, or tricyclic antidepressants (such as amitriptyline), among others. Consult your doctor or pharmacist for details.