Drug Interaction Report

Before starting ponesimod, let your doctor know if you are currently receiving treatment with quiNIDine. Using ponesimod in this situation can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. You may also 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. 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.

Do not consume grapefruit or grapefruit juice during treatment with quiNIDine unless specifically directed otherwise by your doctor. Grapefruit and grapefruit juice can interact with quiNIDine and increase the levels of quiNIDine in your body. If you are already consuming grapefruit products, do not increase or decrease the amount of these products in your diet without first talking to your doctor.