What is filgotinib?

Filgotinib, also known by the trade name Jyseleca, is a type of drug known as a JAK inhibitor. These drugs work by limiting the action of Janus kinase enzymes, which are involved in the inflammation that causes the symptoms of rheumatoid arthritis and some other conditions.

Filgotinib isn’t a painkiller, but it can reduce the symptoms and limit the joint damage that could be caused by your condition. If filgotinib works for you, your symptoms should start to improve within the first 12 weeks after you start to take it, and possibly sooner. But you may not notice the full benefit for the first 6 months of treatment.

Who can take filgotinib?

Filgotinib can be prescribed by a consultant rheumatologist for adults with moderate to severe rheumatoid arthritis.

Filgotinib won’t be started if:

  • your condition isn’t active
  • you haven’t tried other treatments for your condition first
  • you have an infection.

Before you’re prescribed filgotinib, doctors may use a scoring system to assess how many of your joints are painful or swollen and how you are feeling. This helps them work out how active your arthritis is. You’ll also need blood tests before treatment starts to see whether the drug is suitable for you.

Your doctor will need to check if you’ve previously been exposed to tuberculosis (TB). Even if you don’t have symptoms, the bacteria that cause TB may still be present in the body, and you may need a course of treatment to deal with this before starting filgotinib.

If you’ve ever had hepatitis you may need regular checks for this as filgotinib may increase the risk of the hepatitis coming back.

Filgotinib is usually prescribed alongside methotrexate unless there are reasons why you can’t take methotrexate. However, it's recommended that filgotinib should not be used alongside other immunosuppressive or biologic drugs or other JAK inhibitors.

Filgotinib is not recommended if you’re pregnant, planning to become pregnant or breastfeeding.

Your doctor may decide not to prescribe filgotinib if you’re taking certain other medicines, including statins and some drugs used to treat high blood pressure or heart problems, or if you’ve had or have any of the following conditions:

  • shingles
  • disease of the lungs, liver or kidneys
  • heart problems, high blood pressure, high cholesterol, or blood clots (deep vein thrombosis or pulmonary embolism)
  • stomach ulcers
  • cancer.

How is it taken?

Filgotinib is taken as a tablet once a day. Your doctor will advise on the dose for you. The tablets should be swallowed whole and taken with a glass of water, either with or without food. In some circumstances, your doctor may decide to alter the dose.

Try to take your dose at the same time each day – if you’re late taking it, just take it as soon as you remember. If you miss your daily dose completely, carry on with the usual dose the next day – do not double it. If you take more than the recommended dose by mistake, contact your doctor straight away.

Because it’s a long-term treatment, it’s important to keep taking filgotinib (unless you have severe side effects):

  • even if it doesn’t seem to be working at first
  • even when your symptoms improve (to help keep your condition under control).

Your doctor may decide to stop filgotinib and try another treatment if your symptoms haven’t improved very much after 6 months.

Side effects and risks

Most people don’t have any side effects, and for those who do, they aren’t usually serious.

You will normally need to have regular tests while you’re on filgotinib to make sure it isn’t having any unwanted effects on your blood, liver or general health.

If you do have very bad side effects, or are worried about your symptoms, you should ask a health professional for advice.

The most common side effects are:

  • feeling sick (nausea)
  • upper respiratory tract infection
  • urinary tract infection
  • dizziness.

If your doctor thinks you could be at increased risk of skin cancer, they may suggest precautions such as wearing sunscreen and regularly checking your skin for new spots or changes to any freckles or moles.

Cases of blood clots have been reported in people taking filgotinib. You should get medical help as soon as possible if you have painful swelling in a leg or arm or if you develop chest pain or shortness of breath, as these could be signs of a blood clot.

You should also tell your doctor or nurse specialist if you develop any of the following after starting filgotinib:

  • a sore throat, fever, or a cough that won’t go away
  • unexplained bruising or bleeding
  • a painful rash
  • any new symptoms that concern you.

Contact your rheumatology team if you come into contact with someone who has chickenpox or shingles. They may suggest a blood test to check your antibody levels. These illnesses can be more severe than usual if you’re on filgotinib, and you may need anti-viral treatment if you develop either of these illnesses.

You may also be more likely to pick up other infections while you’re on filgotinib, especially if you’re over 65, but the tips below should help to protect you.

Tips to reduce your risk of infection

  • Try to avoid close contact with people you know have an infection.
  • Wash your hands regularly and carry around a small bottle of antibacterial hand gel.
  • Keep your mouth clean by brushing your teeth regularly.
  • Stop smoking if you’re a smoker.
  • Make sure your food is stored and prepared properly.
  • Try to keep your home clean and hygienic, especially the kitchen, bathroom and toilets.

If you develop an infection, which may be bacterial, viral or fungal, then you should stop your filgotinib tablets and speak to your doctor to have the infection treated. You should also let your rheumatology team know.

Carrying an alert card

It’s recommended that you carry a patient alert card so anyone treating you will know that you’re on filgotinib.

Effects on other treatments

You’ll probably be taking methotrexate as well as filgotinib. However, it's recommended that filgotinib is not used alongside other drugs that affect your immune system.

Check with your doctor before starting any new medicines, and remember to mention you’re on filgotinib if you’re treated by anyone other than your usual rheumatology team.

You can carry on taking non-steroidal anti-inflammatory drugs (NSAIDs) or painkillers, if needed, unless your doctor advises otherwise.

Don’t use complementary treatments, such as herbal remedies, without discussing this first with your doctor or pharmacist as some of them could interact with filgotinib.


It’s best to discuss vaccinations with your healthcare team before starting filgotinib.

It’s usually recommended that people on filgotinib avoid live vaccines such as measles, mumps and rubella (MMR), chickenpox and yellow fever. But sometimes a live vaccine may be necessary, so you should discuss this with your rheumatology team.

Before you start filgotinib, your rheumatology team may suggest a blood test to check for antibodies against chickenpox. If the result is low, they may recommend vaccination against chickenpox.

If you’re offered shingles vaccination after starting filgotinib, you should not have the live vaccine (Zostavax) but you may be able to have the non-live vaccine (Shingrix) if this is suitable for you.

It’s recommended that you have the vaccination against COVID-19, and the pneumonia and yearly flu vaccines while taking filgotinib. These vaccines are not live, so it’s safe for you to have them.

Having an operation

If you’re thinking about having surgery, talk this over with your specialists. They may advise you to stop filgotinib for a time before and after your operation.


There’s no need to avoid alcohol while taking filgotinib.

Guidelines state that adults shouldn’t have more than 14 units of alcohol a week, and that these should be spread out over the course of the week. In some circumstances your doctor may advise lower limits.

You can find out more about units of alcohol at:

Fertility, pregnancy and breastfeeding

Because filgotinib is a relatively new drug, we don’t yet know how it might affect pregnancy or an unborn baby.

Women who could become pregnant should use effective contraception while being treated with filgotinib and for at least 1 week after stopping the treatment before trying for a baby. Tell your rheumatology team immediately if you become pregnant while you’re on filgotinib.

We don’t yet know whether filgotinib can pass into human breastmilk, so the current advice is not to breastfeed while taking this drug.

Early studies in animals suggested a possible risk that filgotinib might affect male fertility. However, more recent human studies have found no significant effect on male fertility.

You should speak to your doctor if you have any concerns or questions concerning how your medicines might affect pregnancy, fertility or breastfeeding.