Drug Interaction Report

Consumer information for this interaction is not currently available.

CONTRAINDICATED: Pimozide can cause dose-related prolongation of the QT interval. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). The extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s). In addition, certain agents with anticholinergic properties (e.g., sedating antihistamines; antispasmodics; neuroleptics; phenothiazines; skeletal muscle relaxants; tricyclic antidepressants; disopyramide) may have additive parasympatholytic and central nervous system-depressant effects when used in combination with pimozide. Excessive parasympatholytic effects may include paralytic ileus, hyperthermia, mydriasis, blurred vision, tachycardia, urinary retention, psychosis, and seizures.

MANAGEMENT: Coadministration of pimozide with other drugs that can prolong the QT interval is considered contraindicated.

You should avoid the consumption of large amounts of grapefruits and grapefruit juice while taking pimozide. Grapefruit can raise the levels of pimozide in your body. This can affect the rhythm of your heart and cause other side effects. Call your doctor if you have symptoms of blurred vision or nausea. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or fast or pounding heartbeats during treatment with pimozide. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor. You should avoid or limit the use of alcohol while being treated with pimozide. Alcohol can increase the nervous system side effects of pimozide such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. Talk to your doctor or pharmacist if you have any questions or concerns.