Drug Interactions between lidocaine / potassium chloride and pimozide

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.

Grapefruit juice may increase the blood levels of lidocaine, which may increase the risk of side effects such as low blood pressure, slow heart rate, irregular heart rhythm, difficulty breathing and convulsions. Cigarette smoking may reduce the blood levels of lidocaine, which may make the medication less effective. It is best to avoid smoking during lidocaine therapy. Consuming cruciferous vegetables (e.G., broccoli, brussels sprouts) may also reduce the blood levels of lidocaine. Talk to a healthcare professional if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Consumer information for this interaction is not currently available.

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.