What is Leflunomide
Leflunomide is an orally-available disease-modifying antirheumatic drug for the treatment of rheumatoid arthritis (RA) ; it is the first and only drug to be indicated to slow down structural joint damage of RA, so addressing an unmet medical need. 

Leflunomide has strong immunosuppressive and anti-inflammatory effects, and is a commonly used anti-rheumatic drug to improve the condition.
It belongs to isoxazole derivatives, its chemical structure is different from that of previous immunosuppressants, and it can be rapidly and completely converted into active metabolite terifluramide

Leflunomide  Function 
1. Those who are allergic to leflunomide and its metabolites, pregnant women or women who may become pregnant and lactating women are prohibited.
2. Use with caution in patients with severe liver damage and positive serological indicators of hepatitis B or C. Check ALT and white blood cells regularly while taking this medicine.
3. Use with caution in patients with immunodeficiency, uncontrolled infection, active gastrointestinal disease, renal insufficiency, and bone marrow dysplasia.
4. Men who are going to have children should consider interrupting treatment and taking cholestyramine at the same time
5. There is no clinical data on the efficacy and safety of live immunization vaccines during the treatment of this product. Therefore, live immunization vaccines should not be used during chemicalbook administration.
6. There is no research on the efficacy and safety of this product in children, so it is recommended not to use this product for patients younger than 18 years old.
7. If the dose is too large or toxicity occurs, oral cholestyramine or activated charcoal can be used to promote the excretion of leflunomide.
8. The active metabolites of this product can increase the plasma concentrations of diclofenac, ibuprofen, and tolbutamide by 13% to 50%, while the combined use of rifampicin can increase the plasma concentrations of active metabolites by about 40%. In addition, this product may increase the hepatotoxicity of methotrexate