. . "Because of the possibility of serious toxic reactions (which can be fatal), Methotrexate should be used only in life-threatening neoplastic diseases, or in patients with psoriasis or rheumatoid arthritis with severe, recalcitrant, disabling disease which is not adequately responsive to other forms of therapy.Deaths have been reported with the use of methotrexate in the treatment of malignancy, pso" . .