The contribution of metformin added to routine treatment of methotrexate for the patients of psoriasis with metabolic syndrome

The antiproliferative effect of metformin on human keratinocytes has been demonstrated in two in vitro studies. However, the effect of metformin on psoriasis patients has been investigated only in one clinical study and this revealed significant improvement on the disease severity scores of the psoriasis patients with MS. In a review, pharmacodynamics of MTX and metformin were elaborately researched and it was suggested that this two drugs may have a synergistic favorable effect on the treatment of the patients of psoriasis. The purpose of this study was to assess the antipsoriatic effect of metformin added to MTX in the treatment of the patients of psoriasis with MS. The findings of 33 patients of psoriasis who were treated with MTX and completed the study, were evaluated in this study. The PASI, BSA and DLQI scores of 33 patients were evaluated, thirteen of whom were without MS, 15 of whom were with MS and were recommended for lifestyle modification only, and 5 of whom were with MS who were treated with metformin in addition to lifestyle modification. A higher reduction was found in the PASI and BSA scores of the patients with MS who were treated with metformin compared to the patients with MS who were recommended for lifestyle modification only and patients without MS while a lesser reduction was found in the DLQI scores. The proportion of the patients that achieved the PASI 50, PASI 75 and PASI 90 response, was higher in the group of patients with MS who were treated with metformin compared to the patients with MS who were recommended for lifestyle modification only and patients without MS. A statistical analyze of the difference of this parameters between the groups was not performed due to the scarcity of the number of patients with MS who were treated with metformin. These findings give rise to thought of that metformin combined with MTX may contribute to the treatment of the patients of psoriasis with MS. However, studies with large number of patients are needed to clarify the efficacy of metformin in the treatment of the patients of psoriasis. Key Words: Metabolic syndrome, metformin, methotrexate, psoriasis