Drug Interaction Report

Zanubrutinib may reduce the blood levels of methadone, which may make the medication less effective in treating your condition. Additionally, if you have been receiving treatment with methadone, adding zanubrutinib may cause you to experience unpleasant withdrawal symptoms such as watery eyes, runny nose, sneezing, yawning, excessive sweating, goose bumps, fever, chills, flushing, restlessness, irritability, anxiety, depression, pupil dilation, tremor, rapid heart beat, body aches, involuntary twitching and kicking, abdominal cramping, loss of appetite, nausea, vomiting, diarrhea, and weight loss. On the other hand, if you have been receiving both medications, discontinuing zanubrutinib may increase the blood levels of methadone, which could lead to an overdose. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. 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.

Do not use alcohol or medications that contain alcohol while you are receiving treatment with methadone. This may increase nervous system side effects such as drowsiness, dizziness, lightheadedness, difficulty concentrating, and impairment in thinking and judgment. In severe cases, low blood pressure, respiratory distress, fainting, coma, or even death may occur. You should also avoid consuming grapefruit and grapefruit juice, as this may increase the blood levels and effects of oral methadone. High blood levels of methadone can also occasionally 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. Do not exceed the dose of methadone prescribed for you or use the medication more frequently or for a longer duration than prescribed by your doctor. Also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. 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.

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.