Leflunomide Torrent Pharma (Uk) (Leflunomide)

Leflunomide is a DMARD that modulates immune activity in inflammatory joint diseases.

• Rheumatoid arthritis: reduces disease activity and slows joint damage progression.
• Psoriatic arthritis: improves joint symptoms and inhibits structural deterioration.

• Leflunomide inhibits the mitochondrial enzyme dihydroorotate dehydrogenase, which blocks de novo pyrimidine synthesis. This limits the proliferation of activated lymphocytes, thereby reducing the inflammatory response that drives joint damage in autoimmune arthritis.

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

Common Side Effects

• Diarrhoea: mild to moderate gastrointestinal upset.
• Elevated liver enzymes: transient increase in ALT/AST.
• Hypertension: new‑onset or worsening blood pressure.
• Rash: mild skin irritation or erythema.
• Headache: occasional tension‑type headache.
• Nausea: occasional feeling of queasiness.

Serious or Rare Side Effects

• Severe liver injury: hepatitis or hepatic failure.
• Bone marrow suppression: neutropenia, anaemia, or thrombocytopenia.
• Pulmonary toxicity: interstitial lung disease or severe pneumonitis.
• Severe cutaneous reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Infections: opportunistic or severe bacterial infections.
• Teratogenicity: fetal malformations if exposure occurs during pregnancy.

When prescribing Leflunomide, clinicians should consider several safety measures.

• Pregnancy: contraindicated (Category X); effective contraception required.
• Liver function: baseline and periodic monitoring of hepatic enzymes.
• Blood pressure: monitor and manage hypertension.
• Infection risk: assess for active infections before initiation.
• Vaccination: avoid live vaccines during treatment.
• Store at ambient temperature: keep in the original packaging, protect from moisture and light.

Leflunomide interacts with several medicines, requiring careful management.

Major Interactions (Avoid)

• Methotrexate: combined use may increase hepatotoxicity.
• Warfarin: may potentiate anticoagulant effect and raise INR.
• Live vaccines: heightened risk of infection.

Moderate Interactions (Monitor Closely)

• Statins: monitor liver enzymes for additive hepatotoxicity.
• Sulfasalazine: watch for combined bone‑marrow suppression.
• NSAIDs: assess renal function and blood pressure.
• Antihypertensives: possible reduced efficacy.
• Oral contraceptives: may decrease contraceptive effectiveness.