Leflunomide Biogaran (Leflunomide)

Leflunomide is an immunomodulatory DMARD used in inflammatory arthritis conditions.

• Rheumatoid arthritis: reduces joint inflammation, pain, and slows structural damage.
• Psoriatic arthritis: improves joint symptoms and skin lesions, helping to control disease activity.
• Juvenile idiopathic arthritis (selected cases): may be considered when conventional DMARDs are insufficient, under specialist supervision.

• Leflunomide inhibits the mitochondrial enzyme dihydroorotate dehydrogenase, which is essential for de novo pyrimidine synthesis. By limiting pyrimidine availability, the drug suppresses proliferation of activated lymphocytes, thereby reducing the autoimmune response that drives joint inflammation in rheumatoid and psoriatic arthritis.

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

Common Side Effects

• Diarrhoea: mild to moderate gastrointestinal upset.
• Nausea: occasional feeling of sickness.
• Alopecia: reversible hair thinning.
• Rash: skin irritation or erythema.
• Elevated liver enzymes: mild transaminase increase.
• Hypertension: modest rise in blood pressure.

Serious or Rare Side Effects

• Severe liver injury: hepatitis or hepatic failure.
• Bone marrow suppression: neutropenia or anemia.
• Pulmonary toxicity: interstitial lung disease.
• Stevens‑Johnson syndrome: severe skin reaction.
• Severe infections: opportunistic bacterial or viral infections.
• Teratogenicity: potential fetal harm if exposure occurs during pregnancy.

Before initiating therapy, clinicians should assess baseline health and monitor for specific risks.

• Liver function monitoring: check transaminases and bilirubin before start and periodically thereafter.
• Blood pressure assessment: monitor regularly, especially in patients with hypertension history.
• Pregnancy avoidance: contraindicated in pregnancy; effective contraception required.
• Infection vigilance: screen for active infections and delay therapy if present.
• Hematologic surveillance: perform complete blood counts to detect bone‑marrow suppression.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Leflunomide can interact with several medicines, altering efficacy or safety.

Major Interactions (Avoid)

• Warfarin: increased anticoagulant effect, risk of bleeding.
• Rifampin: induces metabolism, reducing leflunomide plasma levels.
• Methotrexate: additive hepatotoxicity risk.

Moderate Interactions (Monitor Closely)

• Hydroxychloroquine: may increase leflunomide exposure.
• TNF‑α inhibitors: combined immunosuppression heightens infection risk.
• Statins: potential for increased muscle toxicity.