Drug Interactions between ibrutinib and pirtobrutinib

Ibrutinib should be taken once daily at approximately the same time everyday. Do not consume grapefruit, grapefruit juice, or Seville oranges unless directed otherwise by your doctor. Grapefruit and Seville oranges may significantly increase the blood levels of ibrutinib. This may increase the risk of side effects such as nausea, vomiting, diarrhea, abdominal pain, constipation, hemorrhage, kidney problems, 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 contact your doctor if you develop paleness, fatigue, dizziness, fainting, unusual bruising or bleeding, fever, chills, diarrhea, sore throat, muscle aches, shortness of breath, blood in phlegm, weight loss, red or inflamed skin, body sores, and pain or burning during urination. Also seek immediate medical attention if you experience signs and symptoms that may suggest kidney damage such as nausea, vomiting, loss of appetite, increased or decreased urination, sudden weight gain or weight loss, fluid retention, swelling, shortness of breath, muscle cramps, tiredness, weakness, dizziness, confusion, and irregular heart rhythm. 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.

Consumption of grapefruit, grapefruit juice, and supplements that contain grapefruit should be avoided during treatment with pirtobrutinib as they may increase the blood levels of pirtobrutinib. This may increase the risk of side effects such as infection, bruising, bleeding, fatigue, muscle pain, diarrhea, swelling, and difficulty breathing. 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.

The recommended maximum number of medicines in the 'BTK inhibitors' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'BTK inhibitors' category:

• ibrutinib
• pirtobrutinib

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.