Strength of Recommendation: B Level of Evidence: II
Leflunomide is a disease-modifying antirheumatic medication that inhibits de novo pyrimidine synthesis. Approved for the treatment of rheumatoid arthritis, it has more recently been studied for the treatment of psoriatic arthritis and psoriasis.
In a large randomized double-blind placebo-controlled trial of 182 patients with both psoriasis and psoriatic arthritis, patients were randomized to placebo or leflunomide at 20 mg daily for 24 weeks. Subjects had a baseline body surface area of psoriasis involvement that was greater than 3% and were allowed concurrent use of low-dose systemic corticosteroids for the treatment of their psoriatic arthritis (15% of the leflunomide-treated group). After 24 weeks of treatment, 17% of the leflunomide-treated subjects achieved a PASI 75 versus 8% of those receiving placebo (P = .048) and 59% of the patients treated with leflunomide and 30% of the patients treated with placebo (P<.001) were responders by the Psoriatic Arthritis Response Criteria.163
Potential toxicities caused by leflunomide are predominantly gastrointestinal irritation (diarrhea, nausea, dyspepsia), but also include elevated liver enzymes, leukopenia, drug eruption, headaches, increased risk of infections,164 and teratogenicity. In the randomized double-blind placebo-controlled trial of leflunomide for psoriasis and psoriatic arthritis, side effects that occurred at a higher frequency in the leflunomide group than the placebo group included diarrhea, elevated AST levels, lethargy, and leukopenia.163
Loading dose of 100mg/d for 3 days followed by 20 mg/d long term.
When referencing this guideline in a publication, please use the following citation: Menter A, Korman NJ, Elmets CA, Feldman SR, Gelfand JM, Gordon KB, et al. Guidelines of care for the management of psoriasis and psoriatic arthritis: section 4. Guidelines of care for the management and treatment of psoriasis with traditional systemic agents. J Am Acad Dermatol. 2009 Sep;61(3):451-85.
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