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Leflunomide - What is it for

Leflunomide blocks the formation of deoxyribonucleic acid (also known as DNA), which is important for developing cells, such as those in the immune system. However, it is not completely clear how this medication works in rheumatoid arthritis.

It is one of the disease-modifying-anti-rheumatic drugs (DMARDs) which can modify the progress of clinical disease by reducing permanent damage to joints caused by continuing inflammation.

It is often a second-line drug used to treat rheumatoid arthritis if initial drugs are not helping substantially.

It may be combined with other DMARDs or biologic agents to control the disease.

Leflunomide - Side Effects, Precautions, and Contraindications

What side effects can Leflunomide cause?

Symptom frequently improves with time or medications given to prevent diarrhea. If diarrhea persists, the dose of leflunomide may need to be reduced, as decided by your doctor.

Less common side effects include nausea, stomach pain, indigestion, rash, or hair loss.

It may cause abnormal liver function tests or decreased blood cell or platelet counts.

Rarely, it may cause lung problems such as cough, shortness of breath or lung injury.

Before taking Leflunomide , what precautions must I follow?

Come back to the hospital for regular blood test as instructed by your doctor.

Because adverse effects can happen at any time during the course of treatment and some side effects may not cause symptoms, it is really important that you have your regular blood and eye test. 

What food or medicine must I avoid when I take Leflunomide ?

    What special DIETARY instructions should I follow?

  • Alcohol should be avoided if possible or kept to a minimum as suggested by your rheumatologist because alcohol may increase the risk of liver toxicities associated with leflunomide.

    Can I take other MEDICINES or SUPPLEMENTS?

  • You should not take leflunomide if you have a pre-existing liver disease such as hepatitis or cirrhosis.

  • Leflunomide can cause liver injury, so alcohol and certain other medications should be avoided e.g. rifampicin; blood test should be performed regularly to monitor liver function.\Certain medications e.g. cholestyramine can reduce the efficacy of leflunomide.

  • You should avoid live vaccines such as live polio, yellow fever, rubella (German measles), MMR (measles, mumps and rubella), typhoid and BCG (tuberculosis). Flu and pneumococcal vaccines are safe and may be given if required.

Leflunomide - Dosage and How to Use

How should Leflunomide be used?

    How is the medicine given?

  • It is given orally, after food, usually once-a-day.
  • A typical dose will range from 10mg to 20mg daily.
  • When first started on leflunomide, doctors may prescribe a "loading dose" to quickly build up the drug in the body and speed up the onset of the drug.
    • The loading dose is usually 100mg a day for the first 3 days.
    • Alternatively, 100mg given once weekly for 3 weeks while taking the regular daily dose may be prescribed.
    • The loading dose increases the chances of experiencing diarrhea, but this side effect usually improves after completing the loading dose.
    • Omission if loading dose is acceptable with the knowledge that there may be a slight delay in response time.
  • The dose will vary for each person depending upon factors such as activities of your disease and your response to the treatment.

    What is the TIME to EFFECT?

  • Improvement is usually first seen in 3-4 weeks. The full benefits of this drug may not be seen until after 12 weeks of treatment.

  • You need to take it continuously to keep your symptoms controlled.

What should I do if I miss a dose?

  • If you forget to take a dose, take it as soon as you remember.
  • If it is almost time for your next dose, skip the missed dose an continue with your regular dosing schedule.
  • Do not double the dose to make up for the missed dose.

What should I do if I overdose?

Leflunomide - Handling

How should I handle Leflunomide safely?

Leflunomide - Storage

How should I store Leflunomide ?

;#Keep away from children;#Keep in a cool, dry place, away from direct sunlight;#

How should I dispose of Leflunomide safely?

Leflunomide - Additional Information

    Do I skip dose if I am SICK?

  • Seek prompt advice from your doctor when you develop any of the serious symptoms of infection.
  • Your doctor will decide whether to stop leflunomide on a case-by-case basis.


  • This medication can cause serious birth defects, and this risk may persist long after the drug is discontinued.
  • Women of childbearing potential should not receive therapy until pregnancy has been excluded and they have been counseled concerning fetal risk. Use of an effective form of birth control is critical throughout the course of this treatment and for up to two years after it is stopped. This is important, because leflunomide lasts in the body a long time, even after stopping the medication, and could still cause birth defects during this time.
  • It is not known if males taking leflunomide may contribute to fetal toxicity. Men should use effective contraception for 3 months after stopping leflunomide.
  • Both men and women who are on the medication and want to have a child should ask their doctors to prescribe another drug—cholestyramine—to help remove leflunomide from their systems.
  • For mothers receiving leflunomide, breastfeeding is not recommended.

    In SUMMARY… what you need to know about Leflunomide:

  • Take leflunomide once daily, approximately the same time each day.
  • Always come for your BLOOD TESTS on the scheduled date.
  • Beware of the SIDE EFFECTS and when to get immediate medical attention.
  • Never take medicines, supplements or herbal treatments OVER-THE-COUNTER without checking with your doctor or pharmacist first.
  • For female patient intents to start a family, please inform your doctor.
  • If you have further questions about Leflunomide, please call ______________________ (office number) to discuss with your doctor / pharmacist / specialty nurse (please circle as
  • Updated on 6/12/2015 12:00:00 AM
  • Article contributed by Pharmacy, Rheumatology & Immunology Singapore General Hospital
The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth


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