Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of zanubrutinib, which is primarily metabolized by the isoenzyme. When zanubrutinib was administered in clinical study subjects with multiple doses of rifampin, a potent CYP450 3A4 inducer, zanubrutinib peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 92% and 93%, respectively. When coadministered with multiple doses of rifabutin, a moderate CYP450 3A4 inducer, zanubrutinib Cmax and AUC decreased by 48% and 44%, respectively, in healthy subjects. Based on pharmacokinetic modeling, coadministration with multiple doses of efavirenz, another moderate CYP450 3A4 inducer, is predicted to decrease zanubrutinib Cmax and AUC by 58% and 60%, respectively. Reduced efficacy of zanubrutinib may occur. The interaction has not been studied with other, less potent inducers.

MANAGEMENT: The potential for diminished pharmacologic effects of zanubrutinib should be considered during coadministration with CYP450 3A4 inducers. Alternative treatments may be required if an interaction is suspected.

Grapefruit juice and Seville orange juice can increase the blood levels of zanubrutinib. This may increase side effects such as rash, diarrhea, constipation, cough, hemorrhage, development of other cancers, abnormal heart rhythm, and impaired bone marrow function resulting in low numbers of different types of blood cells. You may also be more likely to develop anemia, bleeding problems, or infections due to low blood cell counts. You should avoid the consumption of Seville oranges, Seville orange juice, grapefruit and grapefruit juice during treatment with zanubrutinib. Be sure to take the medication at approximately the same time(s) everyday to maintain consistent blood levels and effects. 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 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.