Drug Interactions between axitinib and Vitamin D3

Treatment with cholecalciferol may require you to adjust your dietary intake of foods which contain natural or added calcium, phosphate (organic and inorganic), and vitamin D. Ingesting too much vitamin D or having elevated calcium and/or phosphorus levels in the blood and urine can lead to toxic effects, such as having an irregular heart rhythm, seizures, kidney stones, and eventual calcification of your blood vessels, cornea and/or the soft tissues in your body. Your doctor will monitor the levels of calcium and phosphorus in your blood during treatment with cholecalciferol. Please speak with your healthcare team to determine if you require a specialized diet, particularly if you have reduced kidney function, and to discuss any other questions or concerns you have. You may require additional monitoring or a dose adjustment of cholecalciferol if your diet changes. Fortified foods will state on their labeling how much calcium, phosphate, and/or vitamin D has been added. The National Institutes of Health, Office of Dietary Supplements also provides information on which foods contain calcium, phosphorus, and vitamin D. You should avoid abrupt changes in your dietary calcium intake and seek medical attention if you experience early symptoms of vitamin D intoxication such as weakness, fatigue, headache, drowsiness, vertigo, ringing in the ears, loss of appetite, nausea, vomiting, constipation, dry mouth, metallic taste, muscle pain, bone pain, muscle incoordination, and low muscle tone. Late symptoms may include frequent urination, excessive thirst, weight loss, conjunctivitis ("pink eye"), light sensitivity, runny nose, itching, increased body temperature, 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.

Do not consume grapefruit or grapefruit juice during treatment with axitinib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of axitinib. This may increase the risk and/or severity of side effects such as high blood pressure, diarrhea, nausea, vomiting, constipation, decreased appetite, weight loss, and rash, itching or peeling of skin on the hands and feet. You may also be more likely to experience less common but more severe side effects such as blood clots (depending on location, can lead to complications such as stroke, heart attack, breathing difficulties, and vision abnormalities); bleeding; liver problems; thyroid problems; tearing (perforation) in the stomach or intestinal wall; and a rare nervous system condition known as reversible posterior leukoencephalopathy syndrome (RPLS). You should seek immediate medical attention if you develop signs and symptoms of these conditions including chest pain or pressure; pain in the arms, back, neck or jaw; swelling; shortness of breath; numbness or weakness on one side of the body; headache; vision changes; seizures, unusual bleeding or bruising; red or black stools; coughing up or vomiting blood or blood clots; and severe stomach or abdominal pain. 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.