Methotrexate: New Therapeutic Approaches

Role of Vitamin C on methotrexate-induced nephrotoxicity in psoriasis context: A preclinical assessment

Methotrexate (MTX) is the most prescribed drug for systemic treatment of psoriasis. However, its clinical use is limited by its nephrotoxicity, which antioxidants can attenuate. This study evaluates the impact of vitamin C (vitC), a well-known antioxidant, on nephrotoxicity induced by high MTX doses in the context of psoriasis. To achieve this purpose, the kidney injury triggered by acute MTX exposure was established in an imiquimod-induced psoriasis-like mouse model. Mice were randomly divided into six groups: group 1 (control); group 2 (Imiquimod, IMQ), group 3 (IMQ+vitC 175 mg/kg/day); group 4 (MTX 20 mg/kg i.p); group 5 (IMQ+MTX 20 mg/kg) and group 6 (IMQ+MTX 20 mg/kg + vitC 175 mg/kg/day). The effects of these treatments were determined by considering the evolution of IMQ-induced skin lesions and serum creatinine levels. Moreover, histopathological analysis, lipid peroxidation, oxidative stress, and TNF-α production were determined in kidney tissue. Results showed that vitC attenuates renal damage in the context of IMQ-induced psoriasis. However, the opposite occurs when administered with IMQ+MTX, worsening skin psoriasis lesions and exacerbating acute renal tubular necrosis and oxidative DNA damage. These results establish new clues about the MTX-induced nephrotoxicity in the psoriasis context and the putative protective effects of vitC. It suggests that vitC supplementation could help attenuate the renal damage promoted by the psoriatic pathological environment. However, it should be avoided in psoriasis patients with renal dysfunction treated with MTX.

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.