Leflunomide

Class

• Pyrimidine synthesis inhibitor

Indications

• rheumatoid arthritis

• psoriatic arthritis

Administration/Absorption

Dosage

Distribution

Mechanism

• Inhibits dihydroorotate dehydrogenase

  • Enzyme involved in de novo pyrimidine synthesis

• Most cells can bypass this blockage

  • Except T cells

  • => anti-inflammatory effect

Excretion

• • Long half-life (2 weeks)

  • Up to 2 years to eliminate completely

Side effects

• • Symptomatic liver damage ranging from jaundice to hepatitis

  • Myelosuppression with leukopenia, and/or hypoplastic anemia, and/orthrombocytopenia

  • Infections

  • Anemia or bleeding episodes

• Interstitial lung disease

• GIT

  • skin reactions

Interactions

• Alcohol, other DMARDs including chloroquine/hydroxychloroquine, live virus vaccines, tegafur, some tuberculostatics (rifampin and/or isoniazid), tolbutamide and warfarin

Contraindications