Drug Interactions between axitinib and phenytoin

Phenytoin levels may decrease when the suspension is given with enteral feedings. This could lead to a loss of seizure control. You could interrupt the feeding for 2 hours before and after the phenytoin dose. Alternatively, you may give the phenytoin suspension diluted in water and flush the tube with water after administration. These would make it easier for your body to absorb the medication. However, this still may not entirely avoid the interaction and may not always be feasible. You should have your phenytoin levels checked upon starting and stopping of enteral feedings. In addition, using phenytoin together with food may alter the effects of phenytoin. Contact your doctor if you experience worsening of seizure control or symptoms of toxicity, including twitching eye movements, slurred speech, loss of balance, tremor, muscle stiffness or weakness, nausea, vomiting, feeling light-headed, fainting, and slow or shallow breathing. 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. Ask your doctor before making any changes to your therapy.

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.