Leflunomide

58 interactions 87 cited references
Also sold as: Arava Arava®
About Leflunomide

Leflunomide is used alone or in combination with other medications to treat rheumatoid arthritis (a condition in which the body attacks its own joints, causing pain, swelling, and loss of function). Leflunomide is in a class of medications called disease-modifying antirheumatic drugs (DMARDs). It works by decreasing in… Read the full Leflunomide drug information page →

Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Aug 9, 2026 · Editorial policy · Data sources

Sources: FDA prescribing information (Structured Product Labeling), the published literature cited in each entry, DDInter 2.0 (a major open-access drug-interaction database), and legacy DrugBank interaction data distributed by the NIH's RxNav service (decommissioned in 2024) — analyzed and reviewed by our pharmacist team. How we build this library →

Most serious with: Teriflunomide Baricitinib Acyclovir Letermovir Injection Methotrexate Injection Adenovirus Vaccine Type 4, Live
1 Contraindicated 52 Major 5 Moderate
All (58) Contraindicated (1) Major (52) Moderate (5)

Major

Leflunomide Rubella Virus Vaccine, Live An increased risk of secondary transmission of infection by the live vaccine and reduced effectiveness of immunization Details Leflunomide Smallpox Monkeypox Vaccine An increased risk of secondary transmission of infection by the live vaccine and reduced effectiveness of immunization Details Leflunomide Sulfasalazine Azulfidine Increased exposure of BCRP substrate Details Leflunomide Tenofovir Alafenamide Increased exposure of BCRP substrate Details Leflunomide Topotecan Hycamtin Increased exposure of BCRP substrate Details Leflunomide Valacyclovir Valtrex Increased exposure of OAT3 substrate Details Leflunomide Varicella Virus Vaccine, Live An increased risk of secondary transmission of infection by the live vaccine and reduced effectiveness of immunization Details Leflunomide Warfarin Coumadin Increased risk of bleeding Details Leflunomide Yellow Fever Vaccine Stamaril An increased risk of secondary transmission of infection by the live vaccine and reduced effectiveness of immunization Details Leflunomide Zoster Vaccine, Live An increased risk of secondary transmission of infection by the live vaccine and reduced effectiveness of immunization Details Leflunomide Letermovir Injection Prevymis Increased exposure of OATP1B1/1B3 substrate Details Leflunomide Methotrexate Injection Abitrexate® Increased exposure of methotrexate and increased risk of hepatotoxicity and bone marrow toxicity Details

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Educational information only, not medical advice. Always confirm interactions with your pharmacist or prescriber before making any change to your medications.