Leflunomide (children)

What is it?

Leflunomide (brand name: Arava, Arabloc) is a medicine which works by reducing the activity of the immune system. Rather than just relieving pain it acts to reduce the damage to the joints. It belongs to the group of medicines called disease modifying antirheumatic drugs (DMARDs).

Other DMARDs commonly used in Juvenile Idiopathic Arthritis are methotrexate, hydroxychloroquine, sulfasalazine. It works on the white blood cells, which are part of the inflammatory process, which causes the pain and swelling of joints in arthritis.

How will it help?

It has been shown to reduce joint damage caused by inflammation, but it is a medicine that works slowly. You can expect your child to start feeling better, but it might take one to two months.

How is leflunomide given?

Leflunomide is taken by mouth in tablet form, and can be taken with or without food. If tablets cannot be swallowed whole, they can be crushed and taken with a chocolate spread or jam.

When should it be given?

Leflunomide is usually taken daily in tablet form.

What is the dose?

The dosage depends on your child’s weight.

How long will it be used for?

Treatment with leflunomide can continue long term to maintain control of arthritis.

Are there any side effects?

Leflunomide usually helps your child’s disease but, as with all medicines, side effects can occur. Some are common, and some are rare. Most young people don’t have any problems when they take leflunomide.

Things you need to know when taking this medicine

What to do if your child is sick

It is safe to give leflunomide even if your child has a cold or cough. Don’t give leflunomide if your child:

  • Has a high fever
  • Has had vomiting/ diarrhoea
  • Has been in contact with chickenpox
  • Is sick and you’re not sure why.

If you’re not sure, talk to your doctor and get them checked if necessary before giving leflunomide.

Regular blood tests are important to monitor side effects.


Leflunomide can interact with other medicines, including over-the-counter and herbal /naturopathic medicines. Always discuss any new medication with your doctor before taking it. Other medicines, such as paracetamol (pain reliever), non-steroidal anti-inflammatory drugs (NSAIDs), and antibiotics, can be taken with leflunomide.


Most immunisations are safe to give (flu vaccine, cervical cancer vaccine, killed polio vaccine (IPV) etc) when on leflunomide. Live virus vaccines (such as mumps, measles, rubella (MMR), polio (OPV)) varicella (chicken pox) and some live vaccines should not be used.


As Leflunomide affects the immune system and can affect the body’s ability to fight infections, contact with adults and children who have contagious illnesses like chicken pox should be avoided where possible. You should report any sign of infection, e.g. fever, to your child’s doctor. Leflunomide can make chickenpox infections more serious. A blood test can be done to see if your child is already immune to chickenpox. If your child is in contact with chickenpox or shingles, call your doctor.


The liver breaks down both leflunomide and alcohol, so drinking alcohol while you are on this medication can put extra strain on the liver. It is not known how much is safe, so it is suggested that anyone on leflunomide should avoid drinking alcohol.

Sexual Health

Leflunomide does not appear to affect fertility, but it may cause a miscarriage or increase the risk of birth defects to the unborn child. For any patient who is sexually active, it is important that adequate contraception is used during treatment and for at least two years after leflunomide has been stopped.

Myths and misconceptions

You may hear a lot of different information about leflunomide from friends, pharmacists or people you know. If you are worried about anything, please talk to your child’s doctor or nurse. If your child is taking leflunomide they should see their paediatric rheumatologist regularly to make sure the treatment is working and to minimise any possible side effects.

This medicine should be kept in a safe place, as accidental overdose can be serious.


For more information please see the Leflunonide (Paediatric) – 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 April 2024