Iodine-based radiographic contrast medium may precipitate metformin-associated lactic acidosis in diabetic patients. A case report, literature review and practical approach.

Lactic acidosis in diabetic patients undergoing metformin therapy is a widely recognized, rare but usually serious adverse event, particularly in presence of comorbidities such as cardiorespiratory disease, sepsis and renal failure. As demonstrated by the case of an elderly woman presented, administration of radiographic iodine-based contrast agents may precipitate lactic acidosis through worsening of renal function. Awareness of this condition, identification of at-risk patients, adequate prevention following published guidelines, early diagnosis and treatment including hemodialysis are necessary to avoid a fatal outcome.