Leflunomide is an immunomodulatory drug with broad immunosuppressive effects. In veterinary neurology, it is most commonly used to treat immune-mediated meningoencephalomyelitis, as it can cross the blood–brain barrier. It may also be used for other immune-mediated conditions.
Because it suppresses the immune system, leflunomide is usually prescribed for long-term management of immune-mediated diseases. It may be combined with other immunosuppressants such as prednisone or cyclosporine; however, using multiple immune-suppressing drugs together increases the risk of infection.
To ensure safety during treatment, blood work (CBC and chemistry panel) is recommended after starting the medication, and then every 6–12 months.
Dosing
Leflunomide is given orally once daily and is well absorbed.
Possible Side Effects
Leflunomide is generally well tolerated, but possible side effects include:
- Lethargy and decreased appetite:Â This side effect is most common. It is usually mild and resolve once the medication is discontinued.
- Elevated liver enzymes:Â Typically transient and monitored with routine blood work.
- Bone marrow suppression: Rarely, this can lead to anemia, low white blood cell count, or low platelet count. This is one reason why regular blood work monitoring is important.