Etrasimod is used to treat ulcerative colitis in adults.

Etrasimod may also be used for purposes not listed in this medication guide.

You should not use etrasimod if you have certain serious heart conditions, especially:

• recent (within the past 6 months) severe heart failure that required you to be in the hospital, heart attack, stroke, "mini-stroke" or transient ischemic attack (TIA), chest pain, or other serious heart problems; or
• irregular or abnormal heart rhythm (unless you have a pacemaker).

Tell your doctor if you have or have ever had:

• an active or chronic infection;
• a weak immune system (caused by disease or by using certain medicine);
• heart rhythm disorder;
• slow heart rate
• heart problems, a heart attack, stroke, or chest pain;
• high blood pressure;
• history of fainting;
• sleep apnea or other breathing problems;
• skin cancer;
• chickenpox or received a vaccine for chickenpox;
• vision problems; or
• liver disease.

Make sure you are current on all vaccines before you start taking etrasimod. You should not receive "live" vaccines at least 4 weeks before starting etrasimod, during treatment, and for 5 weeks after you finish taking etrasimod.

Using etrasimod may increase your risk of developing skin cancer. Ask your doctor about your individual risk.

May harm an unborn baby. You may need a pregnancy test to make sure you are not pregnant. Use effective birth control while using etrasimod and for at least 7 days after your last dose. Tell your doctor if you become pregnant.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of etrasimod on the baby.

Ask a doctor if it is safe to breastfeed while using this medicine.

Use Etrasimod (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives, difficult breathing, swelling of your face, lips, tongue, or throat.

You may get infections more easily, even serious or fatal infections.Your risk of infection could last for 5 weeks after you stop taking this medicine. Call your doctor right away if you have:

• fever, cough, night sweats;
• tiredness, flu-like symptoms;
• pain and burning when you urinate; or
• signs of meningitis--headache, neck stiffness, increased sensitivity to light, nausea, vomiting, confusion, drowsiness.

Also call your doctor at once if you have:

• slow heartbeats, chest pain, shortness of breath, or feel like your heart is skipping beats;
• feeling light-headed, dizziness;
• new or worsening shortness of breath;
• sudden confusion, severe headache, vision loss, or a seizure;
• signs of high blood pressure--pounding in your neck or ears;
• liver problems--loss of appetite, nausea, vomiting, stomach pain, tiredness, itching, dark urine, jaundice (yellowing of the skin or eyes);
• severe vision problems--blurred vision, increased sensitivity to light, seeing an unusual color, or having a blind spot; or
• skin changes, a mole that has changed in color or size.

Your treatment may be delayed or permanently discontinued if you have certain side effects.

Common side effects may include:

• headache;
• abnormal liver function tests; or
• dizziness.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Avoid receiving a vaccine without asking your doctor. The vaccine may not work as well while you are using etrasimod. Receiving a "live" vaccine while using etrasimod may also cause you to develop an infection. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.