leflunomiid

Note: The term “leflunomiid” appears to be a misspelling of leflunomide, a prescription medication used as a disease‑modifying antirheumatic drug (DMARD).

Leflunomide is a synthetic DMARD approved for the treatment of active rheumatoid arthritis, psoriatic arthritis, and, in some cases, plaque psoriasis. It exerts its effects by inhibiting dihydroorotate dehydrogenase (DHODH), reducing de novo pyrimidine synthesis in rapidly dividing lymphocytes and thereby limiting T‑ and B‑cell proliferation.

The drug is taken orally. Typical dosing includes a loading period of 100 mg daily for 3 days, followed by a maintenance dose of 20 mg once daily. Dosing may be adjusted based on liver function, tolerability, and concomitant therapies; lower doses (for example, 10 mg daily) are sometimes used when needed.

Leflunomide is metabolized to teriflunomide, its active metabolite. It has a long elimination half‑life, with clearance potentially taking weeks to months. Because of the prolonged persistence in the body, accelerated elimination strategies using cholestyramine or activated charcoal may be employed in cases of pregnancy or severe toxicity.

Safety and monitoring: Leflunomide is contraindicated in pregnancy and in women planning pregnancy; it should not be used during breastfeeding. Baseline and periodic liver function tests and complete blood counts are recommended. Common adverse effects include hepatotoxicity, diarrhea, nausea, rash, alopecia, hypertension, and neutropenia. It can interact with methotrexate and warfarin, among others.

Brand names include Arava. It has been used since the 1990s as part of RA and psoriatic arthritis treatment, often as an alternative for patients who do not respond to or cannot tolerate methotrexate.