Leflunomide Sandoz (Leflunomide)

• Leflunomide is a disease-modifying antirheumatic drug (DMARD) that targets inflammatory pathways in autoimmune arthritis.
• Rheumatoid arthritis: reduces disease activity, slows joint damage, and improves functional ability.
• Psoriatic arthritis: alleviates joint inflammation, skin lesions, and prevents structural progression.

• Leflunomide inhibits the mitochondrial enzyme dihydroorotate dehydrogenase, which is essential for de novo pyrimidine synthesis. This blockade limits the proliferation of activated lymphocytes, particularly T cells, thereby dampening the immune response that drives chronic joint inflammation in rheumatoid and psoriatic arthritis.

Leflunomide may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Diarrhea or abdominal discomfort
• Nausea and loss of appetite
• Elevated liver enzymes
• Hypertension
• Alopecia or thinning hair
• Rash or mild skin irritation

Serious or Rare Side Effects

• Severe liver injury or hepatitis
• Stevens‑Johnson syndrome or toxic epidermal necrolysis
• Bone marrow suppression leading to anemia or leukopenia
• Interstitial lung disease or pulmonary fibrosis

• Before initiating therapy, clinicians should assess baseline organ function and counsel patients on risk mitigation.
• Monitor liver function: obtain baseline and periodic liver enzyme tests.
• Monitor blood pressure: watch for hypertension and treat as needed.
• Avoid in pregnancy: teratogenic risk requires effective contraception for women of child‑bearing potential.
• Assess infection risk: screen for active infections and avoid use in severe infections.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Leflunomide can alter the pharmacokinetics or pharmacodynamics of several co‑administered medicines.

Major Interactions (Avoid)

• Methotrexate: increased toxicity, especially hepatic and hematologic.
• Warfarin: enhanced anticoagulant effect, risk of bleeding.
• Cholesterol‑binding resins (e.g., cholestyramine): reduced leflunomide absorption.

Moderate Interactions (Monitor Closely)

• Statins: heightened risk of myopathy or rhabdomyolysis.
• Antihypertensives: additive blood‑pressure lowering effect.
• Live vaccines: diminished immunogenic response, consider postponement.