Etrasimod for IBD 

What is etrasimod and how does it work?

Etrasimod is a medicine known as a “sphingosine 1-phosphate (S1P) receptor modulator”. The S1P receptor plays an important role in the body’s immune response. By changing how the S1P receptor acts, etrasimod stops white blood cells (that cause inflammation) from leaving the lymph nodes. For people with inflammatory bowel disease (IBD), this leads to less inflammation in the lining
of the bowel, allowing it to heal.

Why have I been prescribed etrasimod?

Etrasimod is used to treat moderate to severe ulcerative colitis, which is a type of IBD. It is prescribed if other medicines have not worked or are not suitable for you.

How do I get etrasimod?

Etrasimod is an expensive medicine, so there are strict government restrictions and rules to make it available to you at the subsidised (lower) PBS script cost. To ensure you can keep taking etrasimod, you will need to have your IBD assessed every 6 months. This may include having regular blood tests and an appointment with your IBD team.

What checks do I need to have before I start taking etrasimod?

Before you start taking etrasimod, your IBD team may request blood tests, including your full blood count and liver function tests. You may be asked to have an electrocardiogram (ECG), and your blood pressure may be checked. You may also need an eye assessment from an optometrist or ophthalmologist. You should tell your IBD team if you have any heart or lung disease, arrythmias or heart block, diabetes, eye problems or high blood pressure, or if you have ever had a stroke.

You will be screened for infections using blood tests and a chest x-ray. Your vaccinations will also be checked to ensure they are up to date, and you may be advised to have one or more vaccinations before you start taking etrasimod. Please see the Vaccinations and IBD page for more information.

Tell your doctor if you are taking or have previously taken any other medicines, as some medicines cannot be safely taken with etrasimod.

What is the normal dose of etrasimod?

The recommended dose of etrasimod is one 2 mg tablet once a day.

Your IBD team will monitor your body’s response to this medicine and give you information on when to have blood tests done.

How do I take etrasimod?

The etrasimod tablet should be swallowed whole at the same time each day. It can be taken with or without food.

How long will I need to take etrasimod?

If your IBD gets better when you are taking etrasimod, you can keep taking it long term.

What checks will I need to have while I am taking etrasimod?

Regular blood tests are very important because etrasimod can interfere with normal blood cell numbers and can cause liver complications. Regular blood tests can pick up abnormalities in the blood that may not produce symptoms straight away. When you are taking a stable dose of etrasimod, you may only need blood tests every 3–6 months. Your doctor will check your blood
pressure regularly while you are taking etrasimod. You may also be advised to have regular eye examinations while taking etrasimod.

Fertility, pregnancy and breastfeeding

Etrasimod should not be taken during pregnancy because it may be harmful to the unborn baby. Women of childbearing age who are taking etrasimod should use reliable contraception to avoid getting pregnant. You should stop taking etrasimod at least 7 days before a planned pregnancy. Tell your doctor if you are thinking of becoming pregnant or find out that you are pregnant.

It’s recommended to not breastfeed while taking etrasimod and for 7 days after you stop taking it. Talk to your IBD team or lactation nurse before breastfeeding if you have recently taken etrasimod.

What are the possible side effects of etrasimod?

All medicines can cause side effects, although not everyone experiences them. Report any side effects to your IBD team so they can monitor them.

Common side effects:

• Headaches, dizziness, aches and pains, fever, flu-like symptoms, nausea (feeling sick) and diarrhoea: these symptoms will often go away as your body becomes used to the new medicine, but some people may need to swap to a different medicine.
• High blood pressure and slow heartbeat: you may not feel any symptoms from these, but it’s important to see your doctor if you experience any lightheadedness or palpitations (the feeling that your heart is fluttering, pounding or skipping beats).
• Infections: etrasimod may increase your risk of infections like the common cold, urinary tract
  infections or sometimes other more serious infections. Please contact your doctor or IBD team if
  you have any symptoms of infection, like a fever, while taking etrasimod and for up to 14 days after you stop taking it. This can be because your white blood cell count is too low, so this may need to be checked.
• Inflammation of the liver: if this happens, stopping the medicine may bring the results of your liver tests back to normal. You should monitor for signs like yellowing skin, dark urine (wee) and pale stools (poo).
• Shingles: this is a painful rash that can occur in people who have previously had chickenpox. If you
  notice a rash, please see your GP, ideally within the first 3–5 days, as you may need medicine to treat this.

Less common or rare side effects:

• An allergic reaction to etrasimod, such as a rash: seek medical attention immediately if you have any swelling of your face, lips, tongue or throat or have difficulty breathing.
• Macular oedema: tell your doctor right away if you have any changes in vision, including shadows or blind spots in the centre of your vision, blurred vision, or problems seeing colours or details.
• New or worsening breathing problems
• Other serious infections, such as tuberculosis, pneumonia, chickenpox and progressive multifocal
  leukoencephalopathy (PML): you may be screened for these risks and vaccinated if possible. PML is a very rare viral infection in the brain, with symptoms that include increasing weakness on one side of the body or clumsiness of limbs, disturbance of vision and changes in thinking, memory and orientation, leading to confusion and personality changes.
• Posterior reversible encephalopathy syndrome (PRES): this is a very rare condition affecting the
  brain. Tell your doctor right away if you have sudden severe headaches, confusion, seizures, increasing weakness, clumsiness or vision changes.
• There is not yet enough information to know if there is any increased risk of cancer when taking etrasimod; please discuss any concerns you have with your IBD team.

Can I take other medicines while I’m taking etrasimod?

Etrasimod can interact with many types of medicines, which may result in side effects. Your IBD team may ask you for a full list of your medicines, and you should tell your GP, IBD team and pharmacist about any new medicines that you start using.

What can I do to keep myself healthy while I’m taking etrasimod?

• Avoid close contact with people who have transmissible infections, like chickenpox, shingles, whooping cough or measles. Tell your doctor if you have come into contact with anyone who has an infectious condition.
• You should have the flu vaccine every year and the COVID-19, pneumonia, recombinant shingles and human papillomavirus (HPV) vaccines according to the recommended schedule. You should not have any “live” vaccines while taking etrasimod and for some time after stopping it. Please see the Vaccinations and IBD information page for more information.
• Women should have regular cervical screening tests, as recommended by their GP.
• You should use a strong sunscreen and protect your skin when outside. You should not have
  phototherapy for treating skin conditions while you are taking etrasimod. Annual skin checks are
  recommended.
• Always check with your IBD team before starting to take any new medicines, to avoid side effects from interactions with etrasimod.

Contact your IBD team or GP if you have an infection or persistent fever.

This information leaflet has been designed to give you some important information about etrasimod. This information is general and not intended to replace specific advice from your doctor or any other health professional. For more information, please talk to your pharmacist, doctor or IBD nurse.

Acknowledgements:

This resource was developed in 2025 by the GESA IBD Patient Information Materials Working Group