Drug Interactions between entrectinib and sodium phenylbutyrate / taurursodiol

Do not consume grapefruit, grapefruit juice, or Seville oranges during treatment with entrectinib. Doing so can significantly increase the blood levels of entrectinib and increase the risk and/or severity of side effects such as dizziness; confusion; hallucinations; problems with concentration, attention, thinking, and memory; mood changes; insomnia; drowsiness; liver problems; increased uric acid levels in the blood (hyperuricemia); congestive heart failure; fluid retention and swelling; changes in electrical activity of the heart (a condition known as QT prolongation, which may lead to irregular heart rhythm that can be life-threatening); vision problems; and low red or white blood cell counts. Talk to your doctor 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.

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.