Methotrexate (MTX), a folate analogue anti-metabolite, has long been recognized for its beneficial
chemotherapeutic and immuno-modulatory effects and has therefore been used in the past 6 decades to treat a variety of
malignant and autoimmune disorders.
MTX has emerged in the past 2 decades, as a potential drug in the management of patients with chronic pulmonary
diseases including airway hypersensitivity disorders, granulomatous diseases, and auto-immune disorders affecting the
Although bearing a unique hematologic and hepato-pulmonary toxicity profile, some dosing strategies and monitoring
guidelines have been developed in order to ensure a safe utilization. The pulmonary toxicity has a variable clinicopathological
presentation spectrum and a myriad of etiologic factors have been implicated in the pathophysiologic
mechanisms including infectious, immunological, and direct toxic effects.
In the hereby article, we present a brief review of the drug's of mechanism of action, dosing techniques and main side
effects, after which MTX's role in the treatment of asthma, sarcoidosis and vasculitides involving the lung is discussed.
The use of its salvage drug, leucovorin, is also reviewed.