Leflunomide (Arava)

What Is Leflunomide Used For?

Leflunomide is a pyrimidine synthesis inhibitor belonging to the disease-modifying anti-rheumatic class of drugs (DMARD) used to treat symptoms of rheumatoid arthritis. Leflunomide also helps reduce joint damage and improves physical functioning.

Leflunomide is available under the following different brand names: Arava.

What Is the Dosage for Leflunomide?

Dosage Forms and Strengths


  • 10mg
  • 20mg
  • 100mg

Dosage Considerations – Should be Given as Follows:

Rheumatoid Arthritis

100 mg orally once/day for 3 day initially, THEN 10-20 mg orally once/day

Discontinuing leflunomide

Drug elimination process recommended to achieve non-detectable plasma levels (i.e., less than 0.02 mg/L) after discontinuation:

  • Step 1: Administer cholestyramine 8 g orally three times daily for 11 days; the 11 days do not need to be consecutive unless there is a need to lower the plasma level rapidly
  • Step 2: Verify plasma levels less than 0.02 mg/L by 2 separate tests at least 14 days apart; if plasma levels greater than 0.02 mg/L, consider additional cholestyramine treatment Without the drug elimination procedure, it may take up to 2 years to reach plasma M1 metabolite levels less than 0.02 mg/L due to individual variation in drug clearance

Pediatric: Safety and efficacy not established

What Are Side Effects Associated with Using Leflunomide?

Common side effects of leflunomide include:

Serious side effects of leflunomide include:

  • Serious or fatal liver disease
  • Chest pain
  • Fast or pounding heartbeat
  • Increased thirst or urination
  • Muscle cramps or pain
  • Mental/mood changes
  • Vision changes
  • Easy bruising or bleeding
  • Unusual growths or lumps
  • Swollen glands (lymph nodes)
  • Unexplained weight loss
  • Unusual tiredness

Postmarketing side effects of leflunomide reported include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Leflunomide?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

  • Leflunomide has no known severe interactions with other drugs.
  • Leflunomide has serious interactions with at least 68 different drugs.
  • Leflunomide has moderate interactions with at least 34different drugs.
  • Mild interactions of leflunomide include:

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for Leflunomide?


Contraindicated in pregnancy.

Do not use in pregnant women or in women of childbearing age who do not use reliable contraception.

Avoid pregnancy during treatment and during the drug elimination period following treatment (i.e., M1 metabolite less than 0.02 mcg/mL).

Severe liver injury:

  • 49 cases of severe liver injury identified, including 14 cases of fatal liver failure
  • Do not use with pre-existing liver disease
  • Do not use if elevated liver enzymes (ALT greater than 2 times ULN)
  • Coadministration with other drugs that cause liver injury increases risk
  • Recommend ALT monitoring monthly for 6 months after initiating, and every 6-8 weeks thereafter
  • If ALT rises to greater than 3 times ULN, interrupt therapy while investigating probable cause; if likely leflunomide-induced, initiate cholestyramine washout to speed elimination and conduct follow-up LFTs at least weekly until ALT value within normal range; if not leflunomide-induced ALT elevation, may consider resuming leflunomide

This medication contains leflunomide. Do not take Arava if you are allergic to leflunomide or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


Pregnancy, women of childbearing potential (unless contraception used)

Liver disease, hepatitis B/C seropositive

Active serious infections


Concomitant live virus vaccines

Effects of Drug Abuse

No information available

Short-Term Effects

Do not give at late evening; may cause insomnia.

May impair ability to drive and/or operate heavy machinery.

  • See "What Are Side Effects Associated with Using Leflunomide?"

Long-Term Effects

Administration of amphetamine for prolonged periods of time may lead to drug dependence and must be avoided.

  • See "What Are Side Effects Associated with Using Leflunomide?"


Risk of liver damage (hepatotoxicity) (see Warnings).



Potential increase risk for malignancy.

Renal/hepatic impairment.

Rare cases of drug reaction with eosinophilia and systemic symptoms (DRESS) reported; discontinue therapy; a drug elimination procedure recommended.

Co-administration of teriflunomide with leflunomide not recommended, as leflunomide is parent compound of teriflunomide.

Peripheral neuropathy reported; most recover after discontinuing drug; risk factors include age over 60 years, concomitant neurotoxic drugs, and diabetes.

Interstitial lung disease (ILD) reported and has been associated with fatal outcomes; risk increased with prior history of ILD.

Active metabolite A77 1726 has very long half-life and this should be considered when administering live vaccines or planning pregnancy; all women of childbearing potential are advised to receive cholestyramine 8 g three times daily for 11 days to hasten elimination of A77 1726.

If inadvertent pregnancy occurs discontinue immediately and call (877) 311-8972; cholestyramine may reduce risk to fetus.

Severe immunodeficiency.

Stevens-Johnson syndrome and toxic epidermal necrolysis reported (rare).

Severe and disabling joint pain (arthralgia) reported in patients taking DPP-4 inhibitors; consider as a possible cause for severe joint pain and discontinue drug if appropriate.

Pregnancy and Lactation

Do not use leflunomide in pregnancy. The risks involved outweigh potential benefits. Safer alternatives exist. Avoid pregnancy during treatment with leflunomide and during the drug elimination period following treatment. If inadvertent pregnancy occurs discontinue immediately and call (877) 311-8972; cholestyramine may reduce risk to fetus.

It is not known if leflunomide is excreted in breast milk. Consult your doctor before breastfeeding.


Health Solutions From Our Sponsors