Pimozide and alcohol

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.

GENERALLY AVOID: Theoretically, the coadministration with grapefruit juice may increase the plasma concentrations of pimozide. The mechanism is decreased clearance of pimozide due to inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The use of pimozide alone has been associated with dose-dependent prolongation of the QT interval. Although clinical data are lacking, this interaction may result in potentiation of the proarrhythmic effect of pimozide and consequently an increased risk of ventricular arrhythmias such as ventricular tachycardia and torsade de pointes. In addition, alcohol may potentiate some of the pharmacologic effects of pimozide. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: The manufacturer recommends avoiding grapefruit juice (and probably grapefruits) during therapy with pimozide. Patients should also be advised to avoid or limit consumption of alcohol.