Leflunomide (Arava)

Pronunciation: leh-FLOO-noh-mide.

Generic name
leflunomide
Drug class
Disease-modifying antirheumatic drug (DMARD) -- pyrimidine synthesis (dihydroorotate dehydrogenase) inhibitor
Form
Tablet (10 mg, 20 mg, 100 mg)
Route
Oral
Legal status
Prescription-only

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Arava (5) · Full directory

What leflunomide is and how it works

Leflunomide is a prescription-only disease-modifying antirheumatic drug (DMARD) used to treat active rheumatoid arthritis in adults. It works by reducing the activity of certain immune cells that drive joint inflammation. (1)

Take leflunomide exactly as your prescriber directs. Because of its boxed warning for birth defects and liver injury, your prescriber will run specific blood tests before and regularly during treatment, and will discuss pregnancy prevention with you if relevant.

Mechanism of action: how leflunomide works

Leflunomide is a prodrug rapidly converted to its active metabolite (teriflunomide), which inhibits dihydroorotate dehydrogenase, a mitochondrial enzyme required for de novo pyrimidine synthesis, giving antiproliferative and immunomodulatory effects on activated lymphocytes. (1)

What leflunomide is used for

Active rheumatoid arthritis

Used to reduce the signs, symptoms, and joint damage of active rheumatoid arthritis in adults. Some countries also license it for active psoriatic arthritis. Improvement typically begins after about 4-6 weeks and can continue over 4-6 months. (1) (2)

Before taking leflunomide

Do not take / not appropriate for

  • Do not take leflunomide if you are pregnant, or if you could become pregnant and are not using effective contraception -- this medicine is contraindicated in pregnancy due to a real risk of severe birth defects. (all countries) (1)
  • Do not take leflunomide if you have severe liver impairment or a known allergy to leflunomide or its ingredients. (all countries) (1)
  • Do not take leflunomide together with teriflunomide. (United States) (1)

Tell your clinician about

  • Any current pregnancy, plans for pregnancy (for you or a partner), or breastfeeding -- this affects whether leflunomide is suitable and whether an elimination procedure is needed.
  • Any history of liver disease or abnormal liver tests.
  • Any history of tuberculosis or other serious infections, since your prescriber will typically screen for tuberculosis before starting.
  • Any history of lung disease, numbness/tingling in the hands or feet, high blood pressure, or blood count problems.
  • All other medicines you take, including warfarin, hormonal contraceptives, rosuvastatin, and teriflunomide.
(1)

How to take leflunomide

  • Swallow the tablet whole with enough liquid; it can be taken with or without food.
  • Take leflunomide at the same time each day, exactly as your prescriber has set out.
  • Attend all blood tests your prescriber schedules -- these check your liver function and blood counts and are an essential part of taking this medicine safely.
  • If you and your prescriber ever decide together to stop treatment, or if pregnancy is being planned or has occurred, your prescriber will direct an accelerated elimination procedure (using cholestyramine or activated charcoal) to clear the medicine from your body more quickly, followed by blood tests to confirm it has been cleared.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (3) (2) (4) (5) (6)

Missed dose

Contact your prescriber or pharmacist for specific guidance if you miss a dose.

Overdose

Seek urgent medical attention if you think too much leflunomide has been taken. Your prescriber or an emergency clinician may use the accelerated elimination procedure (cholestyramine or activated charcoal) to help remove the medicine from your body. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Diarrhoea and indigestion.

What to notice: Diarrhoea and indigestion.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Respiratory infections.

What to notice: Respiratory infections.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Nausea and headache.

What to notice: Nausea and headache.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Rash and abnormal liver blood test results.

What to notice: Rash and abnormal liver blood test results.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of severe liver injury — boxed_warning

Symptoms: Yellowing of the skin or eyes (jaundice), unusual tiredness, dark urine, loss of appetite, or pain in the upper right abdomen.

Action: Contact your prescriber urgently -- your ALT liver blood test is monitored regularly (at least monthly for the first six months, then every 6-8 weeks) specifically to catch this early. Severe or fatal liver injury has occurred rarely. (1)

Pregnancy or birth-defect risk — boxed_warning

Symptoms: Suspected or confirmed pregnancy while taking leflunomide, or while a partner is planning conception.

Action: Contact your prescriber immediately -- leflunomide is contraindicated in pregnancy due to a real risk of severe birth defects, and your prescriber will direct an accelerated elimination procedure right away. (1)

Signs of a serious infection — emergency

Symptoms: Fever, chills, persistent cough, or any infection that does not improve, since leflunomide affects the immune system.

Action: Contact your prescriber promptly, or seek emergency care for severe symptoms -- your prescriber may have screened for tuberculosis before starting this medicine for this reason. (1)

Signs of interstitial lung disease — emergency

Symptoms: New or worsening cough, or shortness of breath.

Action: Seek urgent medical assessment -- this is a rare but potentially fatal lung condition linked to leflunomide, and your prescriber will assess whether to continue treatment. (1) (6)

Numbness or tingling in the hands or feet (possible peripheral neuropathy) — high caution

Symptoms: New numbness, tingling, or weakness in the hands or feet.

Action: Tell your prescriber promptly -- treatment may need to be reassessed if this develops. (1)

Serious skin reactions — emergency

Symptoms: Widespread blistering or peeling skin, painful sores in the mouth or eyes, fever with rash, or facial swelling.

Action: Seek emergency medical help immediately -- very rare cases of Stevens-Johnson syndrome, toxic epidermal necrolysis, and DRESS have been reported. (2)

Interactions

  • Can reduce the blood-thinning effect of warfarin -- your prescriber will monitor your INR (blood clotting test) more closely. (1)
  • Can increase exposure to hormonal contraceptive medicines. (1)
  • Rosuvastatin doses may need to be limited by your prescriber if taken together. (1)
  • May affect levels of certain other medicines processed by the same liver pathways -- always tell your prescriber about all medicines you take. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Contraindicated. Leflunomide caused birth defects and pregnancy loss in animal studies at doses below typical human exposure. Pregnancy must be excluded before starting, effective contraception is required during treatment, and your prescriber will direct an accelerated elimination procedure with confirmatory blood testing if pregnancy is planned or occurs. (1) (3) (2) (4) (5) (6)

Breastfeeding

Breastfeeding is generally not recommended during treatment, on your prescriber's advice, since the active form of the medicine has been found in animal milk studies. (1) (3) (2) (4) (5) (6)

Children

Not established as safe and effective in children in the sources reviewed; this is an adult rheumatoid arthritis medicine. (1) (3) (2) (4) (5) (6)

Elderly

No specific dose adjustment based on age alone is described in the sources reviewed beyond the usual individualised, monitored approach. (1) (3) (2) (4) (5) (6)

Hepatic_impairment

Contraindicated in severe hepatic impairment; liver function is closely monitored throughout treatment in all patients. (1) (3) (2) (4) (5) (6)

Renal_impairment

Tell your prescriber about any kidney problems so they can be factored into your monitoring plan. (1) (3) (2) (4) (5) (6)

Monitoring

Before starting

  • Pregnancy test where relevant
  • Baseline liver function tests
  • Baseline full blood count
  • Tuberculosis screening
  • Blood pressure check

During treatment

  • ALT (liver) blood tests at least monthly for the first six months, then every 6-8 weeks.
  • Full blood count on the same schedule as ALT monitoring.
  • Regular blood pressure checks.
  • Watching for new cough, breathlessness, numbness/tingling, or signs of infection between visits.
(1) (6)

Storage

Store at 25°C (77°F); brief excursions between 15-30°C are permitted. Protect from light. Keep out of reach of children.

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information; verify against the current full label before prescribing.

United States

Indication: Active rheumatoid arthritis in adults

Dose summary: Individualised by hepatotoxicity risk profile: lower-risk patients may use a short loading dose (100 mg daily for 3 days) then 20 mg daily maintenance; higher-risk patients typically start at 20 mg daily without loading. Dose may be reduced to 10 mg daily if not tolerated.

Renal context: Not specifically detailed in the source reviewed; hepatic function is the primary monitored parameter. (1)

Mechanism of action

Hepatic guidance

Contraindicated in severe hepatic impairment; regular ALT monitoring required in all patients given the risk of severe, occasionally fatal, hepatotoxicity.

Overdose note

Management includes the accelerated elimination procedure (cholestyramine or activated charcoal) as used for planned pregnancy or suspected toxicity, alongside supportive care. (1)

Frequently asked questions

Is leflunomide (Arava) available in the US, UK, Europe, Canada, Australia, and New Zealand?

Yes, it is approved and available in all of these regions, both as the brand Arava and as generic leflunomide in most markets. (1) (3) (2) (4) (5) (6)

Can I take leflunomide if I am pregnant or planning a pregnancy?

No. Leflunomide is contraindicated in pregnancy because of a real, verified risk of severe birth defects, and this is one of its boxed warnings. If pregnancy is being planned or occurs, your prescriber will discuss an accelerated elimination procedure to clear the medicine from your body before conception is attempted. (1)

Why do I need regular blood tests while taking leflunomide?

Leflunomide carries a boxed warning for liver injury, so your liver function (ALT) and blood counts are checked on a set schedule -- usually monthly for the first six months, then every 6-8 weeks -- to catch any problems early. (1) (6)

What is the mechanism of action of leflunomide?

Leflunomide is a prodrug rapidly converted to its active metabolite (teriflunomide), which inhibits dihydroorotate dehydrogenase, a mitochondrial enzyme required for de novo pyrimidine synthesis, giving antiproliferative and immunomodulatory effects on activated lymphocytes. (1)

What is the generic name of Leflunomide (Arava)?

The generic name is leflunomide. (1)

What class of drug is leflunomide?

Leflunomide (Arava) is classed as: Disease-modifying antirheumatic drug (DMARD) -- pyrimidine synthesis (dihydroorotate dehydrogenase) inhibitor. (1)

References

  1. ARAVA (leflunomide) tablets -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, Sanofi-Aventis U.S. LLC · United States · accessed 2026-07-29 · source 1
  2. Arava 20mg Tablets -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Sanofi · United Kingdom · accessed 2026-07-29 · source 2
  3. Arava -- European Public Assessment Report (EPAR)European Medicines Agency (EMA) · European Union · accessed 2026-07-29 · source 3
  4. ARAVA (Leflunomide) Product MonographHealth Canada product monograph · Canada · accessed 2026-07-29 · source 4
  5. ARAVA Leflunomide 20 mg tablet -- ARTG registrationTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-29 · source 5
  6. ARAVA (Tablets) -- New Zealand Data SheetMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-29 · source 6

Brand names by country

Single-ingredient leflunomide names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Arava20 mg, 100 mg, 10 mg · sanofi-aventis u.s. llc

United Kingdom

  • Arava (2)MHRA licensed emc smpc confirmed · 10 mg, 20 mg tablets · Sanofi

Canada

  • ARAVA

Australia

  • Arava (5)TGA ARTG registered 1999-10-11 confirmed · 10 mg, 20 mg, 100 mg tablets · Sanofi-Aventis Australia Pty Ltd

New Zealand

  • Arava (6)Medsafe approved confirmed · 10 mg, 20 mg tablets · Sanofi
View brands in additional countries.

European Union

Arava (3)

This page provides general reference information about leflunomide (Arava) and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions should be made with your prescriber.

Related medicines

Related conditions