METFORMIN-INDUCED LACTIC ACIDOSIS: SHOULD THE MEDICATION BE DISCONTINUED PRE-OPERATIVELY?

Abstract

Introduction: In recent decades, the prevalence of diabetes mellitus (DM) has increased significantly. Metformin is the most common hypoglycemic medication prescribed worldwide in diabetic patients, although its use is potentially hampered by the risk of lactic acidosis associated with metformin. Objectives: to analyze whether there is a need to discontinue treatment with metformin in the preoperative period due to the incidence of lactic acidosis. Materials and methods: This is an integrative review, in which the guiding question was “is there a need to discontinue treatment with metformin in the preoperative period due to the incidence of lactic acidosis associated with the medication in the postoperative period?”. The search for articles took place in PubMed using the terms “lactic acidosis” and “metformin”, combined using Boolean operators. Results and discussion: The ideal plasma concentration of metformin is < 2 mcg/mL, while levels above 5 mcg/dL are of concern. In diabetic patients without high-risk features for metformin accumulation, continuation of metformin before and after coronary angiography with or without percutaneous coronary intervention resulted in similar preprocedural and 72-hour lactate levels. Concomitant administration of metformin during percutaneous coronary interventions in patients with relatively preserved renal function is safe. Conclusion: plasma lactate levels before and after surgical procedures were similar, thus demonstrating that there is no need to discontinue the medication before carrying out the procedures if the patient's renal function is preserved.