Drug Interactions between dronedarone and selumetinib

Do not consume grapefruit or grapefruit juice during treatment with dronedarone unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of dronedarone to dangerous levels. This may increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. 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. 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.

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.