Drug Interaction Report

Ribociclib may increase the blood levels of selumetinib. This may increase the risk and/or severity of serious side effects such as diarrhea; colitis (inflammation of the colon); skin rashes; cardiomyopathy (a condition that affects the heart muscle and its ability to pump blood); rhabdomyolysis (a rare condition involving the breakdown of skeletal muscle tissue that can cause kidney damage and death); and eye problems that can lead to blindness. 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 prompt medical attention if you experience severe diarrhea; severe skin reactions (rash over a large area of the body, peeling skin, blisters); signs and symptoms of heart trouble (persistent coughing or wheezing, shortness of breath, swelling of ankles and feet, fatigue, increased heart rate); muscle problems (unexplained muscle pain, tenderness or weakness, especially with fever and/or dark colored urine); or vision problems (blurred vision, light sensitivity, dark spots or floaters, vision loss). 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.

Ribociclib may increase the blood levels and effects of letrozole. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if your condition changes or you experience increased side effects. 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.

Letrozole may increase the blood levels of selumetinib. This may increase the risk and/or severity of serious side effects such as diarrhea; colitis (inflammation of the colon); skin rashes; cardiomyopathy (a condition that affects the heart muscle and its ability to pump blood); rhabdomyolysis (a rare condition involving the breakdown of skeletal muscle tissue that can cause kidney damage and death); and eye problems that can lead to blindness. 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 prompt medical attention if you experience severe diarrhea; severe skin reactions (rash over a large area of the body, peeling skin, blisters); signs and symptoms of heart trouble (persistent coughing or wheezing, shortness of breath, swelling of ankles and feet, fatigue, increased heart rate); muscle problems (unexplained muscle pain, tenderness or weakness, especially with fever and/or dark colored urine); or vision problems (blurred vision, light sensitivity, dark spots or floaters, vision loss). 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.

Grapefruit juice can increase the blood levels of selumetinib. This may increase the risk and/or severity of serious side effects such as diarrhea; colitis (inflammation of the colon); skin rashes; cardiomyopathy (a condition that affects the heart muscle and its ability to pump blood); rhabdomyolysis (a rare condition involving the breakdown of skeletal muscle tissue that can cause kidney damage and death); and eye problems that can lead to blindness. Do not consume grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with selumetinib. Talk to your doctor or pharmacist if you have any questions or concerns. You should seek prompt medical attention if you experience severe diarrhea; severe skin reactions (rash over a large area of the body, peeling skin, blisters); signs and symptoms of heart trouble (persistent coughing or wheezing, shortness of breath, swelling of ankles and feet, fatigue, increased heart rate); muscle problems (unexplained muscle pain, tenderness or weakness, especially with fever and/or dark colored urine); or vision problems (blurred vision, light sensitivity, dark spots or floaters, vision loss). 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.

Patients should not consume pomegranates, pomegranate juice, grapefruit, or grapefruit juice during treatment with ribociclib unless directed otherwise by your doctor. Pomegranate juice or grapefruit juice can increase the blood levels of ribociclib. You may be more likely to experience side effects such as nausea; vomiting; diarrhea; loss of appetite; abdominal pain; mouth sores; hair loss; weakness; 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.