Drug Interactions between axitinib and Synthroid

The timing of meals relative to your oral levothyroxine dose can affect the absorption of the medication. Therefore, levothyroxine should be taken on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in blood levels, which may alter its effects. In addition, absorption of levothyroxine may be decreased and/or delayed by foods such as soybean flour, cotton seed meal, walnuts, dietary fiber, calcium, calcium fortified juices and grapefruit or grapefruit juice. These foods should be avoided within several hours of dosing if possible. 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.

Using multivitamin with minerals together with levothyroxine may decrease the effects of levothyroxine. You should separate the administration of levothyroxine and multivitamin with minerals by at least 4 hours. If your doctor does prescribe these medications together, you may need a dose adjustment or special test 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.