Drug Interaction Report

Palbociclib may increase the blood levels of fostamatinib. In some cases, this may increase the risk and/or severity of side effects such as nausea, diarrhea, high blood pressure, liver problems, and low white blood cell counts. You may also be more likely to develop infections as a result of low white blood cell counts. You should seek immediate medical attention if you have signs and symptoms of infection such as 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. 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.

Palbociclib oral capsules (Ibrance) should be taken with food to help with its absorption. Palbociclib oral tablets (Ibrance) may be taken with or without food. Do not consume grapefruit or grapefruit juice during treatment with palbociclib. Grapefruit and grapefruit juice can interact with palbociclib and increase the levels of palbociclib in your body. You may be more likely to experience side effects such as nausea; vomiting; diarrhea; loss of appetite; mouth sores; hair loss; weakness; pain, numbness, or tingling in the hands and feet; and impaired bone marrow function resulting in low numbers of different types of blood cells, which can increase the risk of anemia, bleeding problems, and infections. 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.