Drug Interactions between crizotinib and sodium phenylbutyrate / taurursodiol

Do not consume grapefruit or grapefruit juice during treatment with crizotinib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of crizotinib to dangerous levels and cause an irregular heart rhythm that may be serious. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or fast or pounding heartbeats during treatment with crizotinib. You may take crizotinib with or without food, but take it the same time each day. 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.

Food may affect the absorption of sodium phenylbutyrate. A high-fat, high-calorie meal (approximately 800 to 1000 calories; 500 to 600 calories from fat, 250 calories from carbohydrate, 150 calories from protein) has been shown to reduce the absorption of sodium phenylbutyrate, although it is unknown what impact this may have on the overall effectiveness of the medication. The manufacturer recommends taking sodium phenylbutyrate before a meal or snack. This is especially important if you weigh less than 70 kg (approximately 154 pounds). Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication without first talking to your doctor.