Leflunomide Print Page

What is Leflunomide?

  • Leflunomide, its tradename Arava, is in a class of medications called Disease Modifying Anti-Rheumatic Drugs, or DMARDs. DMARDs are a slow acting but effective treatment for rheumatoid arthritis and other forms of inflammatory arthritis.
  • Leflunomide is a newer DMARD considered by some to be equivalent in effect to methotrexate for rheumatoid arthritis.
  • It can also used in the treatment of other types of inflammatory arthritis, vasculitis, myositis and others.

What is the typical dose for Leflunomide?

  • Leflunomide comes in tablet form. Most rheumatologists will start Leflunomide at 20mg daily. However, 10mg daily and 20mg every second day are also reasonable & common, and depends on the individual patient.

How does Leflunomide work?

  • While there has been extensive research into this area, it remains unclear as to the exact mechanism of action. Its primary mechanism is through an effect it has on lymphocyte function, a specific type of white blood cell.

How soon will I feel the effects of leflunomide?

  • Like all DMARDs, leflunomide takes time to work. Most patients start to feel the positive effects of leflunomide at 4-8 weeks, with maximum benefit at 3-6 months. Side effects can occur earlier.

What are the possible side effects of leflunomide?

  • Some of the side effects of leflunomide are similar to methotrexate. Side effects may include:

Side Effect Ways to Reduce Side Effects
  • Leflunomide can cause gastrointestinal upset. In particular, diarrhea can be a significant problem for some patients on leflunomide.
  • If you are having problems, discuss it with your rheumatologist immediately. They will either adjust the dose or stop it completely.
  • Hair Thinning
  • While not that common, it can be very distressing to some people. Speak to your rheumatologist if you notice this.
  • Leflunomide can decrease your blood counts.
  • Your rheumatologist will provide you with a requisition for monthly bloodwork to check your blood counts. While rare, if there is a problem, your rheumatologist will usually see it in your bloodwork well before you notice any problems. Make sure you always get your bloodwork.
  • Make sure your doctor knows if you have a pre-existing problem with your blood cells
  • Leflunomide can cause liver irritation.
  • Like your blood counts, your rheumatologist will also monitor liver tests on a monthly basis.
  • Limit your alcohol intake to 2-3 drinks per week.
  • Leflunomide can cause an increase in your blood pressure.
  • Have your blood pressure monitored by your rheumatologist or family physician.
  • Pregnancy miscarriages or malformations
  • You or your partner should not become pregnant if you are on leflunomide.
  • Leflunomide stays in your system for at least 1-2 years even once you stop it. Your doctor will need to give you special medication to remove leflunomide from your system prior to trying to become pregnant. Therefore, it is very important to discuss pregnancy plans with your rheumatologist.
  • Mothers should not nurse if on leflunomide as it can enter the breast milk.
  • More infections
  • There is a small increased risk of developing infections, particularly if used in combination with steroids. You should be more careful when you are sick, and let your doctor know if you have a fever.

My doctor started me on leflunomide and methotrexate at the same time. Because they both can affect my blood counts and liver, is this safe?

Both you and your rheumatologist should be more cautious if you are taking both methotrexate and leflunomide at the same time as there is an increased risk of some side effects. However, this is a common combination which can be effective in treating your condition. Often, your rheumatologist will lower the dose of one of these medications to improve the safety. Of course, it is also important to ensure you continue to do your regular bloodwork as scheduled.

What should I do if I miss a dose?

You can safely take your dose later in the day. If you do not remember until the next day, just take your regular dose; do not take a double dose. As long as this does not happen regularly, you should not experience any ill effects.

How can I safely stop leflunomide?

It is safe to just stop leflunomide; you do not need to slowly reduce the dose. However, keep in mind, if you were gaining any benefit from leflunomide, it will usually take at least 6 weeks to lose it. If you are stopping because of more severe side effects, your doctor may recommend a medication regimen to clear the leflunomide out of your system, as it can otherwise remain in you for 1-2 years.


For more information about leflunomide, or for questions that are specific to your situation, always consult your physician.

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