Drug Interaction Report

Tazemetostat 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.

Do not consume grapefruit or grapefruit juice during treatment with tazemetostat. Grapefruit juice can significantly increase the blood levels and effects of tazemetostat, which may increase the risk of serious side effects such as bleeding complications, pain, bone pain, tiredness, shortness of breath, excess fluid around the lungs, and development of new (second) cancers. 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.