Efficacy of Leflunomide Compared to Methotrexate in the Treatment of Moderate to Severe Plaques Psoriasis: A Randomized Controlled Clinical Trial.

Introduction: Psoriasis is a chronic inflammatory autoimmune skin disease. Several treatment options are available including topical and systemic options. Methotrexate was the main systemic medication in treating severe psoriasis, yet adverse events can limit its use. Leflunomide is an isoxazole derivative that inhibits the synthesis of pyrimidines, and subsequently inhibits RNA and DNA synthesis.

Objectives: As available data directly comparing MTX to leflunomide in psoriasis are lacking, this double blinded study was designed to compare the efficacy of methotrexate versus leflunomide in the treatment of moderate to severe psoriasis.

Methods: The study included 40 patients (25 males and 15 females) with chronic plaque psoriasis. s. Patients were randomly assigned to one of two equal groups, group A for subcutaneous methotrexate injections and group B for leflunomide (loading dose 100mg daily for the first 3 days, then 20 mg daily for 3 months. Disease severity was determined by psoriasis area and severity index (PASI) score before and at the end of treatment The treatment response was evaluated at the baseline and weeks 4, 8 and 12 PASI score.

Results: Both groups were matching at the baseline in aspects of gender, age, disease duration and PASI scores Both medications yielded comparable results with no significant difference between both groups in PASI score neither in side effects.

Conclusions: Leflunomide can be as effective as methotrexate in treatment of moderate to severe psoriasis.