Drug Interaction Report

Mavacamten may increase the blood levels and effects of thiotepa. You may have increased side effects such as nausea, vomiting, mouth ulcers, skin conditions, and low blood cell counts, which can make you more likely to develop anemia, bleeding problems, and infections. Your doctor may already be aware of the risks but has determined that this is the best course of treatment for you and has taken appropriate precautions and is monitoring you more closely. Contact your doctor if you experience potential signs and symptoms of these conditions such as paleness of skin, fatigue, dizziness, fainting, unusual bleeding or bruising, fever, chills, sore throat, body aches, or other flu-like symptoms. You may need a dose adjustment or additional monitoring by your doctor 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.

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.