Drug Interaction Report

Before starting etrasimod, let your doctor know if you are currently receiving treatment with doxepin topical. Using etrasimod 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.

Grapefruit juice may increase the blood levels of etrasimod. You should avoid grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with etrasimod unless directed otherwise by your doctor. Talk to your doctor if you have any questions or concerns. Contact your doctor if your condition changes or you experience increased side effects, such as fever, high temperature or flu-like symptoms, severe headache, confusion, seizures, dizziness, tiredness, lightheadedness, chest pain, shortness of breath, or irregular or abnormal heartbeat, blurriness or shadows in the center of your vision, and nausea, vomiting, abdominal pain, anorexia, or jaundice and/or dark urine. 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.