Drug Interactions between infigratinib and mavacamten

Infigratinib should be taken on an empty stomach, at least 1 hour before or 2 hours after food. Do not consume grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with infigratinib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of infigratinib. This may increase the frequency and severity of serious side effects such as infections; decreased red blood cell, white blood cell, and platelet counts; fever; abdominal pain; increased blood calcium and phosphate levels above normal; eye and vision problems; mouth sores and inflammation; diarrhea; redness, swelling, peeling or tenderness, mainly on the hands and feet ('hand-foot syndrome'); nails separating from the bed or poor formation of the nail; and changes in kidney function blood tests. 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.

Grapefruit juice may increase the blood levels of mavacamten and increase the risk of heart failure, a condition where the heart is unable to pump blood adequately to meet the body's needs. Your risk may be further increased if you develop a serious infection or irregular heartbeat during treatment with mavacamten. You should avoid the consumption of grapefruit and grapefruit juice while taking this medication. Talk to your doctor if you have any questions or concerns. You should seek medical attention if you experience signs and symptoms of heart failure such as shortness of breath, chest pain, fatigue, swelling in your legs, palpitations, or rapid weight gain. 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.