What is Baricitinib?

Baricitinib (brand name Olumiant®) is a tablet that belongs to a class of medicines called Janus Kinase (JAK) inhibitors. JAK inhibitors work by blocking signals involved in inflammation. Blocking these signals in rheumatoid arthritis reduces pain, stiffness, swelling and damage in the joints.

What benefit can you expect from your treatment?

You may notice some relief of joint swelling, pain and stiffness within the first 2 to 4 weeks of treatment, although it can take up to 3 months to improve.

Stopping Baricitinib

  • If you stop or delay your baricitinib treatment, your disease may get worse. Keep taking your treatment, unless advised by your rheumatologist to stop or unless serious side effects occur (see Side effects).
  • If you stop baricitinib for any reason you must contact your rheumatologist. Failure to do so may mean that your treatment may no longer be funded.

How will your condition be monitored?

  • Medicines like baricitinib are very expensive and are highly funded by Medicare. Certain conditions must be met to receive it.
  • Baricitinib will only be given if your disease is active and if standard treatments have not worked.
  • It will only be kept going if it helps your condition. This will be checked around 12 weeks after the start of treatment.
  • Blood tests are needed during your treatment to watch for side effects and to decide if the treatment is working.
  • How often you have blood tests will depend on what other medicines you are taking and what other illnesses you have. Your rheumatologist will advise on this.

How is Baricitinib taken?

Baricitinib is taken by mouth in tablet form. The tablet should be swallowed whole do not crush or break the tablet.

When should it be taken?

  • Take this medicine with a full glass of water at the same time each day. It can be taken with or without food.
  • If you miss a dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

What is the dosage?

The usual starting dose of baricitinib is one 4mg tablet, (although your doctor may choose to start a lower dose.) This may be reduced to the 2mg tablet dose if you respond well to treatment. If you have poor kidney function you may begin on the 2mg dose.

Can other medicines be taken with baricitinib?

Baricitinib may be used alone or with other arthritis medicines including:

  • other disease modifying anti rheumatic drugs (DMARDs) such as methotrexate
  • steroid medicines such as prednisolone or cortisone injections into the joint
  • anti-inflammatory medicines (NSAIDs) such as naproxen (Naprosyn®) or ibuprofen (Brufen®, Nurofen®)
  • simple pain medicines such as paracetamol.

If you are taking probenecid tell your doctor as you may need a lower dose of baricitinib.

Baricitinib cannot be used with other biologic DMARDs or targeted synthetic DMARDS (such as tofacitinib).

Are there any side effects?

You might experience side effects with your treatment. Tell your doctor if you notice side effects that you think are caused by this medicine. Many side effects disappear when baricitinib treatment is stopped.

Most common side effects

  • Baricitinib is associated with an increase in infections. These are mainly viral infections of the upper respiratory tract (nose, throat and sinus infections) and urinary tract infections. Infections may need treatment and baricitinib may need to be stopped for a while if you develop an infection, so it is important to contact your doctor for advice.
  • Gastrointestinal related – nausea (feeling sick), vomiting and diarrhea.
  • Blood test abnormalities. This can include an increase in some blood components such as platelets and a decrease in others such as two types of white cells and haemoglobin, causing mild anemia. If baricitinib is ceased the blood usually returns to normal.

Less common or rare side effects

  • Blood clots in the veins of the legs or lungs and arteries are possible in some people taking baricitinib. This can happen more often in patients with an inflammatory condition. Further risk factors including heart disease will be assessed by your doctor.
  • Serious infections such as tuberculosis (TB) are seen rarely, and screening for TB is needed before treatment begins.
  • Increases in lipid (cholesterol) levels have been noted in some patients when taking baricitinib and will be checked using blood tests.
  • Changes in liver function have been seen. It is recommended to have regular liver function tests.
  • Baricitinib increases the risk of getting shingles. If you get a painful skin rash with blisters inform your doctor immediately. Vaccination for shingles should be discussed with your rheumatologist before starting treatment.
  • People with rheumatoid arthritis are at increased risk of lymphoma and some other cancers. Medicines that change your immune system like baricitinib may increase this risk.
  • Skin cancers have been reported in people taking baricitinib and yearly skin checks are recommended.
  • Tell your doctor or pharmacist immediately of any of side effects you experience.
  • Blood counts: Although abnormalities are usually mild sometimes baricitinib will cause a severe abnormality of your liver or blood.

** May 2023: A safety warning has been added to a class of medicines called Janus Kinase (JAK) Inhibitors used for chronic inflammatory conditions. This class of medicines have been found to increase the risk of major cardiovascular events, such as heart attack and stroke, cancer, blood clots, serious infections and death. If you are taking this medication, please ensure you discuss your medication management with your Specialist as soon as possible.

What precautions are necessary?


  • If you have an active infection of any kind treatment with baricitinib will not be started until the infection is treated successfully.
  • Baricitinib will not be given if you have active untreated tuberculosis (TB) or HIV (AIDS) infection as it is likely to make these conditions worse.

Use with other medicines

  • Baricitinib can interact with other medicines. You should tell all your doctors about all medicines you are taking or plan to take. This includes over the counter or herbal/naturopathic medicines.


  • If you are taking baricitinib you should not be immunised with ‘live’ vaccines such as:
  • MMR (measles, mumps and rubella), varicella vaccines (chicken pox/shingles) OPV (oral polio virus), BCG (Bacillus Calmette Guerin) or Yellow Fever. Talk with your rheumatologist before receiving any vaccines.
  • Pneumococcal vaccines and the yearly seasonal flu vaccinations are encouraged.
For more information on vaccination including the COVID-19 vaccination go to the Vaccination page on the ARA website



  • If you require surgery for any reason treatment with baricitinib should be stopped one week before surgery. It will be restarted again after the operation at a time agreed by your surgeon and rheumatologist (usually when the wound is healed).

Use in pregnancy and when breastfeeding

  • It is important to discuss with your doctor if you are planning a pregnancy while on baricitinib.
  • Baricitinib should not be used during pregnancy. Women of childbearing potential should use effective birth control both during treatment and for at least 1 week after final dose of baricitinib.
  • Do not breastfeed if you are taking baricitinib as it is uncertain how much of the drug might be excreted in breast milk.
More detailed information is available here.

How to store baricitinib

  • Store baricitinib in a cool, dry place, away from direct heat and light (for example, not in the bathroom)
  • Keep all medicines out of reach of children.

Important things to remember

  • You must see your rheumatologist regularly to make sure the treatment is working and check for possible side effects.
  • You should have regular blood tests as suggested by your rheumatologist.
  • It is important to tell your rheumatologist if you have a new serious illness such as a serious infection, cancer or heart failure.
  • If you are worried about any side effects, you should contact your rheumatologist as soon as possible.
  • If you stop baricitinib for any reason, you must contact your rheumatologist. Failure to do so may mean that your treatment may no longer be funded.
  • If you plan to become pregnant, you must discuss the timing with your rheumatologist

For more information see the Baricitinib – printable information sheet.

This Information Sheet has been prepared using materials obtained from various sources which have been reviewed by the Australian Rheumatology Association (ARA). It contains general information only and does not contain a complete or definitive statement of all possible uses, actions, precautions, side effects or interactions of the medicines referenced. This information is not intended as medical advice for individual conditions nor for making an individual assessment of the risks and benefits of taking a particular medicine. Decisions regarding the assessment and treatment of patients are the sole responsibility of the treating medical professional, exercising their own clinical judgment and taking into account all of the circumstances and the medical history of the individual patient. ARA has used all reasonable endeavours to ensure the information on which this Information Sheet is based is accurate and up to date. However, the ARA accepts no responsibility or liability for the accuracy, currency, reliability and/or completeness of the information contained in this Information Sheet.  To the maximum extent permitted by law, the ARA expressly disclaims any liability for any injury, loss, harm or damage arising from or in connection with use of and reliance on the information contained in this Information Sheet. This information sheet is copyright and may be reproduced in its entirety but may not be altered without prior written permission from the ARA.Page updated September 2023