Drug Interactions between Ingrezza and mavorixafor

Grapefruit and grapefruit juice may increase the blood levels and effects of valbenazine, such as drowsiness and an irregular heart rhythm problem called QT prolongation. Irregular heart rhythm problems may be serious and potentially life-threatening, although it is a relatively 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 questions or concerns. Do not add grapefruit products to your diet, or increase or decrease the amount currently in your diet without first talking to your doctor. You may need a dose adjustment of valbenazine or more frequent monitoring by your doctor to safely use both valbenazine and grapefruit products. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with these 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.

Mavorixafor should be taken on an empty stomach after an overnight fast, 30 minutes before food. Do not consume grapefruit products during treatment with mavorixafor unless otherwise directed by your doctor. Grapefruit juice can increase the blood levels and adverse effects of mavorixafor, increasing the risk of experiencing a change in the electrical activity of your heart called QT prolongation, which can result in irregular heartbeats that can be life-threatening. You should seek immediate medical attention if you experience an irregular heartbeat or feel dizzy, lightheaded, or faint during treatment. Speak with your doctor or healthcare provider if you have any questions. 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.