Leflunomid Sandoz (Leflunomide)

• Leflunomide is used to modify disease activity in autoimmune joint disorders.
• Rheumatoid arthritis: reduces joint inflammation, pain, and structural damage.
• Psoriatic arthritis: improves skin lesions and joint symptoms.
• Active disease in adults: helps control symptoms and slows progression of autoimmune arthritis.

• Leflunomide is metabolized to its active form, teriflunomide, which selectively inhibits dihydroorotate dehydrogenase, a key enzyme in de novo pyrimidine synthesis. This blockade limits the proliferation of activated T‑lymphocytes and other immune cells, thereby reducing the autoimmune response that drives joint inflammation and damage.

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

Common Side Effects

• Diarrhoea: loose stools, often mild to moderate.
• Nausea: feeling of sickness, may accompany meals.
• Alopecia: thinning or loss of hair.
• Rash: skin redness or itching.
• Elevated liver enzymes: increased ALT/AST on blood tests.
• Hypertension: rise in blood pressure readings.

Serious or Rare Side Effects

• Severe liver injury: jaundice, hepatic failure.
• Stevens‑Johnson syndrome or toxic epidermal necrolysis: severe skin reactions.
• Bone marrow suppression: anemia, leukopenia, thrombocytopenia.
• Interstitial lung disease: cough, shortness of breath.
• Opportunistic infections: due to immune suppression.
• Teratogenicity: birth defects if exposure occurs during pregnancy.

• Before initiating therapy, several safety considerations should be reviewed.
• Pregnancy contraindication: avoid use in pregnancy and discontinue well before conception.
• Liver function monitoring: obtain baseline tests and repeat periodically.
• Blood pressure assessment: monitor regularly, especially in hypertensive patients.
• Hematologic surveillance: check complete blood count for signs of suppression.
• Severe hepatic impairment: contraindicated in patients with existing liver disease.
• Store at below 25°C: keep in the original container, protect from moisture and direct sunlight.

Leflunomide can affect the pharmacokinetics or safety profile of several concomitant medicines.

Major Interactions (Avoid)

• Warfarin: increased anticoagulant effect, risk of bleeding.
• Methotrexate: additive hepatotoxicity and bone‑marrow suppression.
• Cholesterol‑binding resins (e.g., cholestyramine): reduce leflunomide exposure.
• CYP3A4 inducers (e.g., rifampicin): markedly lower plasma levels.
• Teriflunomide (active metabolite): combined exposure increases toxicity.

Moderate Interactions (Monitor Closely)

• Statins: heightened risk of myopathy.
• Azathioprine: potential for enhanced myelosuppression.
• TNF‑α inhibitors: increased infection risk when used together.
• Oral contraceptives: reduced efficacy, consider alternative contraception.
• Vitamin K antagonists: may require dose adjustment.