Drug Interaction Report

Palbociclib may increase the blood levels of dofetilide in some patients. High blood levels of dofetilide can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting). 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. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment. 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.

Information for this minor interaction is available on the professional version.