Drug Interaction Report

Ranolazine may increase the blood levels and effects of fesoterodine. You may need a dose adjustment if you have been taking fesoterodine and are starting treatment with ranolazine. Let your doctor know if you experience excessive drowsiness, dizziness, irregular heartbeat, blurry vision, difficulty urinating, dry mouth, headache, gastrointestinal upset, or constipation while taking these medications, as they may be symptoms caused by excessive effects of fesoterodine. 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.

You may take ranolazine with or without food, but should try to take it the same way every time. Grapefruit and grapefruit juice should be avoided if possible. Grapefruit juice can increase the levels of ranolazine in your body. High blood levels of food can occasionally cause an irregular heart rhythm that may be serious. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, or fast or pounding heartbeats during treatment with ranolazine. 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.

Grapefruit juice may increase the levels of fesoterodine in your body. Let your doctor know if you experience excessive drowsiness, dizziness, irregular heartbeat, blurry vision, difficulty urinating, dry mouth, headache, gastrointestinal upset, or constipation while taking fesoterodine. 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.