Drug Interaction Report

Using deutetrabenazine together with glasdegib can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a rare side effect. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting). Talk to your doctor if you have any questions or concerns. 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 closely for any potential complications. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with these medications, whether together or alone. 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 and grapefruit juice may increase the blood levels and effects of glasdegib. This can increase the risk of serious side effects such as an irregular heart rhythm, inflammation and ulceration of the digestive tract, low red or white blood cells, fever, low platelet levels, bleeding, and swelling. You should avoid consumption of grapefruit and grapefruit juice during treatment with glasdegib. Otherwise, you may need a dose adjustment and/or more frequent monitoring by your doctor to safely use this medication. 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.