Metformin in COVID-19 therapy in patients with diabetes mellitus: benefit or harm?

Diabetes mellitus is one of the most common comorbidities among patients with coronavirus disease 2019 (COVID-19), which can complicate the course of this new viral infection. In turn, metformin is an antihyperglycemic drug with an immunomodulatory effect that relieves severe inflammation and reduces damage to lung tissue. This review aims to summarize the data available in the literature on the possibility of using metformin, its effectiveness and mechanisms of action in the treatment of COVID-19 in patients with diabetes mellitus.