Leflunomide is used to treat rheumatoid arthritis by reducing signs and symptoms, improving physical function and preventing the development of structural damage to the joints. 


What is Leflunomide?

Leflunomide is a pyrimidine synthesis inhibitor. It is thought to work by blocking certain enzymes responsible for abnormal tissue development or growth.


How should Leflunomide be taken?

Leflunomide is administered orally.


Side effects associated with Leflunomide

Leflunomide may increase the risk of liver problems, interstitial lung diseases and toxic epidermal necrolysis . It may also reduce the number of platelets in the blood and the body’s ability to fight infections.


Among the other possible side effects of leflunomide include the following:


  • Back ache
  • Diarrhea
  • Dizziness
  • Hair loss
  • Headache
  • Indigestion
  • Muscle aches
  • Nausea
  • Runny nose
  • Weakness
  • Weight loss


It is important to contact a doctor immediately if you experience:


  • Rash
  • Urticaria
  • Difficulty breathing
  • Tightness in the chest or chest pain
  • Swelling of the mouth, face, lips or tongue
  • Blisters inside the eyes, nose or mouth
  • Burning, numbness, or tingling
  • Irregular or accelerated heartbeat
  • Muscle cramps
  • Severe breathing problems
  • Redness, swelling, blistering or peeling of the skin
  • Severe or persistent vomiting
  • Symptoms of high blood pressure
  • Symptoms of infections
  • Symptoms of kidney problems
  • Bruising  or bleeding
  • Unusual tiredness 
  • Pallor


Contraindications and warnings associated with the use of Leflunomide

Leflunomide is contraindicated during pregnancy, breast-feeding, in case of liver or bone marrow problems, a weakened immune system or severe uncontrolled infections. It is also prohibited in individuals with a history of hepatitis B or C and those who are taking teriflunomide.


The intake of leflunomide can impair the ability to drive or operate hazardous machinery. This side effect can be aggravated by alcohol and certain other medications.


Before starting treatment with leflunomide, it is important to tell your doctor if:


  • You have any allergies to the active substance, its excipients or to any other drugs, food or various substances
  • You are taking any other medications, herbal remedies or supplements. Mentioning in particular:  antimalarial, methotrexate, rifampin, teriflunomide, anticoagulants, drugs that may suppress the immune system or cause nerve problems, cholestyramine and drugs that may cause liver problems
  • You have recently used methotrexate, other anti-rheumatic drugs or any medication that may suppress immune system functions
  • You are suffering (or have suffered) from problems to the immune system, blood or bone marrow infections (recurrent), pulmonary disorders, tuberculosis, high blood pressure, diabetes, liver or kidney problems
  • You have recently received a vaccination
  • You have recently tested positive on the tuberculin skin test
  • You drink alcohol on a regular basis
  • You are on dialysis
  • You are pregnant or breast-feeding


During treatment, it is important not to undergo live vaccines. Moreover, women of childbearing age should continue to use birth control methods during treatment and for at least two years after discontinuation of therapy. At the end of the therapy, certain medications may be prescribed to help eliminate drug residue from the body.