leflunomide at a glance
Medicine class
Disease-modifying antirheumatic drug and selective immunosuppressant
Licensed use
Active rheumatoid arthritis in adults
Monitoring
Regular blood counts, liver tests and blood-pressure checks are required
Food
May be taken with or without food
What is leflunomide used for?
Leflunomide is licensed as a disease-modifying treatment for adults with:
Active rheumatoid arthritis
How does leflunomide work?
Leflunomide is converted to an active metabolite that inhibits an enzyme needed to make pyrimidines. This limits the expansion of activated immune cells involved in rheumatoid inflammation.
leflunomide preparations and strengths
How to take leflunomide
Follow the specialist’s instructions and the dispensing label.
Swallow the tablet with sufficient liquid.
Take it with or without food.
The score line helps with swallowing; it does not divide the tablet into equal amounts.
Avoid alcohol because it may increase the risk of liver injury.
leflunomide side effects
Common or expected effects
- Diarrhoea, nausea, vomiting or abdominal pain
- Headache, dizziness or tingling
- Increased hair loss, rash, itching, eczema or dry skin
- Mouth ulcers
- Reduced appetite, mild weight loss or tiredness
- Mildly raised blood pressure
- Changes in liver tests or white blood-cell count
Get urgent medical advice
- Severe allergic reaction, including swelling, breathing difficulty or collapse
- Blistering, peeling or widespread rash, especially involving the mouth or eyes
- Fever, sore throat or other signs of severe infection
- Jaundice or significant abdominal pain suggesting liver injury
- Unexplained bruising, bleeding, marked pallor or severe tiredness suggesting a blood disorder
- New cough or breathlessness suggesting lung inflammation
- New persistent tingling, weakness or pain in the hands or feet
leflunomide in pregnancy
Leflunomide is contraindicated during pregnancy, and reliable contraception is required. Its active metabolite can remain in the body for a long time. Anyone planning pregnancy, whose period is late or who becomes pregnant should promptly contact their specialist; supervised elimination and blood tests may be needed.
leflunomide while breastfeeding
Leflunomide must not be used while breastfeeding because its active substance or metabolites may pass into breast milk. Discuss an alternative treatment or feeding plan with the specialist.
leflunomide interactions
Tell the prescriber and pharmacist about all medicines, supplements and planned vaccinations. Important examples include:
Methotrexate and other liver-toxic or bone-marrow-suppressing medicines
Combined or closely sequential use may increase liver and blood toxicity, requiring specialist assessment and closer monitoring.
Warfarin and other coumarin anticoagulants
The anticoagulant response may change, so close INR monitoring is required.
Live attenuated vaccines
These are not recommended during treatment. Leflunomide’s prolonged persistence must also be considered after stopping.
Common questions about leflunomide
Answers are fully visible for fast scanning and source review.
Is leflunomide a painkiller?
No. It acts on the inflammatory disease process rather than providing immediate pain relief.
How long does leflunomide take to work?
Improvement commonly begins after several weeks and may continue to build over several months.
Why are blood tests needed?
They help detect liver injury and changes in white cells, red cells or platelets before complications become severe.
Can I have vaccinations?
Discuss vaccinations with the clinical team. Live attenuated vaccines are not recommended, including after treatment while leflunomide remains in the body.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.