Drug Interaction Report

Ivacaftor may increase the blood levels of sparsentan. This may increase the risk of side effects such as hepatotoxicity, acute kidney injury, hyperkalemia (high blood potassium), edema, and hypotension. Talk to your doctor if you have any questions or concerns. You may need more monitoring to safely use both medications. You should seek medical attention if you have fever, chills, joint pain or swelling, dizziness, fainting, confusion, shortness of breath, weak pulse or a slow or irregular heartbeat, unusual bleeding or bruising, tingling of the hands and feet, feelings of heaviness in the legs, muscle aches, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, diarrhea, abdominal pain, dark urine, pale stools, and/or yellowing of the skin or eyes, or pain or burning during urination. 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.

If you are taking sparsentan you should avoid potassium-containing salt substitutes or over-the-counter potassium supplements without first talking to your doctor. This can cause high levels of potassium in your blood. High levels of potassium can cause weakness, irregular heartbeat, confusion, tingling of the extremities, or feelings of heaviness in the legs. Call your doctor at once if you have any of these symptoms.

Consumption of grapefruit, grapefruit juice, and supplements that contain grapefruit should be avoided during treatment with sparsentan as they may increase the blood levels of sparsentan. This may increase the risk of side effects such as hepatotoxicity, acute kidney injury, hyperkalemia, edema, and hypotension.

Swallow sparsentan whole with water before your morning or evening meal. Take your dose with the same meal each day. Talk to your doctor if you have any questions or concerns. 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.

Ivacaftor should be taken with fat-containing foods such as eggs, avocados, nuts, meat, butter, peanut butter, cheese pizza, and whole-milk dairy products to help with its absorption. Do not consume grapefruit juice or any food that contains grapefruit or Seville oranges during treatment with ivacaftor unless directed otherwise by your doctor. Grapefruit juice can significantly increase the blood levels of ivacaftor. This may increase the risk and/or severity of serious side effects such as liver damage. Call your doctor immediately if you have fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, abdominal pain, dark urine, pale stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. 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.