Arava (Leflunomide)

How does it work?

Arava tablets contain the active ingredient leflunomide, which is a type of medicine called a disease-modifiying antirheumatic drug (DMARD). It is mainly used to treat rheumatoid arthritis.

Rheumatoid arthritis is known as an autoimmune disease. The inflammation and damage to the joints in this disease result from overactivity in the immune system. Leflunomide works by suppressing the excessive activity of the immune system and modifying the process of inflammation. This actually slows progression of the underlying disease.

It is not understood exactly how leflunomide works. However, it is known that it prevents the activation and multiplication of white blood cells known as lymphocytes, which are responsible for causing inflammation.

By preventing the activation of these lymphocyte cells, blood levels of certain inflammatory chemicals that the body's immune system produces in rheumatoid arthritis are reduced. Once these have fallen, the inflammation of the joints lessens, which helps relieve the pain.

You should not expect this medicine to start to reduce the pain in your joints for at least four to six weeks after starting treatment, because it can take this long to start working. However, your symptoms may then continue to improve for the next four to six months of treatment. After this you will then usually have to continue taking the medicine long-term to keep your arthritis under control.

What is it used for?

  • Moderate to severe rheumatoid arthritis.
  • A form of arthritis called psoriatic arthritis that can occur in people with the skin condition psoriasis.

Leflunomide is used when other disease modifiying antirheumatic drugs (DMARDs, eg sulfasalazine, methotrexate) have not been effective.


  • This medicine may rarely have side effects on your liver or blood cells. Before starting treatment with Arava you will need to have blood tests to check your liver function and blood cells. These tests should also be carried out every two weeks during the first six months of treatment and then every eight weeks throughout treatment
  • If you experience any of the following symptoms while taking this medicine you should consult your doctor because they may suggest a problem with your liver: persistent nausea and vomiting, abdominal pain, or yellowing of the skin or whites of the eyes (jaundice).
  • Alcohol should be avoided whilst taking this medicine as it may increase the risk of side effects on the liver.
  • If you experience any of the following symptoms while taking this medicine you should consult your doctor because they may suggest a problem with your blood cells: unexplained bruising or bleeding, purple spots, sore throat, mouth ulcers, high temperature (fever), feeling tired or general illness.
  • Your blood pressure should be regularly monitored while you are taking this medicine. If your blood pressure rises too high you may be prescribed a medicine to lower it.
  • This medicine can compromise the body's ability to fight infections. Cases of serious infections have been seen in people treated with this medicine. It is important to try and avoid exposure to infections during your treatment. Let your doctor know as soon as possible if you get any symptoms of any infection, so that it can be treated without delay. If you develop a serious infection, treatment with this medicine should be stopped until the infection is controlled.
  • This medicine may be harmful to an unborn baby. For this reason, women will need to have a pregnancy test before treatment with this medicine is started. Women taking this medicine who could get pregnant must use a highly effective method of contraception (such as an injected or implanted form) to prevent pregnancy. You will be given advice on which forms are suitable for you. Contraception should be started before your treatment begins and continued all the time you are taking this medicine. You should continue to use contraception to prevent pregnancy for at least two years after your treatment is finished. You should consult your doctor immediately if you think you could be pregnant.
  • Men taking this medicine should use condoms to avoid fathering a child, both during treatment and for at least three months after treatment is finished.
  • Leflunomide can last for a long time in the body after treatment is stopped. For this reason, it may sometimes be necessary to take other medicines to help remove leflunomide from the body after stopping treatment; this is known as a washout procedure. It is especially important to wash out leflunomide from the body if you are going to start treatment with another DMARD, if serious side effects have been experienced, or if you are planning a pregnancy.

Use with caution in

  • People with a history of tuberculosis infection.
  • People with low numbers of red blood cells (anaemia), white blood cells (leucopenia or neutropenia) or platelets (thrombocytopenia) in their blood, or problems with their bone marrow.
  • People who are taking or who have recently taken other medicines that can affect liver function or blood cells.

Not to be used in

  • Decreased liver function.
  • Moderately to severely decreased kidney function.
  • People with unusually low amounts of protein in their blood (hypoproteinaemia), eg due to the kidney disorder nephrotic syndrome.
  • People with serious infections, including active tuberculosis.
  • People with a severely underactive immune system, eg due to AIDS.
  • People with significant bone marrow disorders.
  • People with significantly low numbers of red blood cells (anaemia), white blood cells (leucopenia or neutropenia) or platelets (thrombocytopenia) in their blood, due to causes other than their arthritis.
  • Pregnancy.
  • Women who could get pregnant (unless using a recommended method of contraception).
  • Breastfeeding.
  • Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Arava tablets contain lactose).
  • The manufacturer has not studied this medicine in children and adolescents under 18 years of age. It is not recommended for this age group.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • This medicine may cause serious birth defects and must not be used during pregnancy. Women who could get pregnant must use a highly effective method of contraception to prevent pregnancy, both during treatment with this medicine and for at least two years after the treatment is finished. Tell your doctor immediately if you think you could be pregnant.
  • Women who want to have a baby after stopping treatment with this medicine should seek medical advice from their doctor. You need to make sure that all traces of the medicine have left your body before you get pregnant, which can take up to two years. If this is too long to wait, your doctor can prescribe certain medicines to help washout the medicine from the body in a few weeks. Either way, before you start trying for a baby you should have a blood test to check that the medicine has been sufficiently removed from your body, and then wait at least another month before getting pregnant.
  • Men taking this medicine should use condoms to avoid fathering a child, both during treatment and for at least three months after treatment is finished.
  • Men who want to father a child after stopping treatment should consult their doctor, because they also need to wait for the medicine to be sufficiently removed from their body. Your doctor can prescribe medicines to speed up this process when you stop taking Arava. After taking these you will need to have a blood test to check the level of the medicine in your blood has fallen sufficiently low, and then wait a further three months before trying for a baby.
  • This medicine passes into breast milk. Women should not breastfeed during treatment with this medicine. Seek further medical advice from your doctor.

Label warnings

  • Avoid alcoholic drink.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

  • Disturbances of the gut such as indigestion, nausea, vomiting, diarrhoea or abdominal pain.
  • Mouth ulcers.
  • Hair loss (alopecia).
  • Headache.
  • Dizziness.
  • Pins and needles (paraesthesia).
  • Disturbances of liver function.
  • Skin reactions eg rash, itching, irritation, dry skin, blistering.
  • Raised blood pressure.
  • Decrease in the number of white blood cells, red blood cells or platelets in the blood.
  • Fatigue, weakness or loss of strength (asthenia).
  • Inflammation of the tissue surrounding a tendon (tenosynovitis).
  • Change in taste.
  • Loss of appetite.
  • Anxiety.
  • A rare form of lung irritation called interstitial lung disease (if you get a sudden new or worsening cough, high temperature (fever), wheezing or shortness of breath while taking this medicine, you should let your doctor know).
  • Disorder of the peripheral nerves causing weakness and numbness in the arms and legs (peripheral neuropathy).
  • Severe infections (see warning above).
  • Liver disorders such as liver inflammation (hepatitis) or liver failure (see warnings above).
  • Inflammation of the pancreas (pancreatitis).
  • Serious blistering or peeling skin reactions, eg Stevens-Johnson syndrome, toxic epidermal necrolysis, ulcerative stomatitis (consult your doctor if you get a skin rash, skin peeling or sores inside your mouth while taking this medicine).

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.

It is recommended that leflunomide is not taken in combination with the following DMARD medicines which are also used for treatment of rheumatoid arthritis:

  • azathioprine
  • chloroquine
  • gold treatment, eg auranofin, sodium aurothiomalate
  • hydroxychloroquine
  • methotrexate
  • penicillamine.

There may be an increased risk of side effects on the liver or blood cells if this medicine is taken by people who are, or who have recently been, receiving other treatments that can affect the liver or blood cells.

There may be an increased risk of infections if this medicine is used to treat people who are or who have recently been receiving treatment that suppresses the activity of the immune system,eg long-term oral corticosteroids, chemotherapy, radiotherapy or medicines to prevent transplant rejection.

This medicine suppresses part of the immune system. This means that vaccines may potentially be less effective if given during treatment, and live vaccines may cause serious infections. Live vaccines include: measles, mumps, rubella, MMR, oral polio, oral typhoid and yellow fever. It is recommended that live vaccines are not given to people being treated with this medicine and for a certain period of time after stopping the treatment.

Leflunomide may increase the blood levels of the following medicines:

  • phenytoin
  • tolbutamide.
  • warfarin (if you are taking warfarin your blood clotting time (INR) may need to be monitored more frequently; in particular your INR should be measured after you start treatment with leflunomide).

This medicine should not be given at the same time as the cholesterol lowering medicine colestyramine, or with charcoal tablets, as they both significantly reduce the amount of leflunomide in the blood. These medicines are sometimes used to washout leflunomide from the body when this medicine is stopped (see warning section above).

Rifampicin can increase the amount of leflunomide in the blood.

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain leflunomide as the active ingredient.