Metformin-induced lactic acidosis: a case series

Area of Science:

• Endocrinology
• Nephrology
• Pharmacology

Background:

• Metformin is a widely used oral hypoglycemic agent for type 2 diabetes mellitus.
• It is associated with reduced mortality in obese patients, leading to increased use of higher doses.
• A significant concern with metformin use is the potential risk of lactic acidosis.

Purpose of the Study:

• To present two case reports of severe lactic acidosis.
• To investigate the association between high-dose metformin and lactic acidosis in patients without contraindications.
• To highlight the importance of considering lactic acidosis in metformin users.

Main Methods:

• Presentation of two distinct case reports of patients experiencing severe lactic acidosis.
• Detailed medical history, clinical presentation, laboratory findings, and treatment interventions for each patient.
• Inclusion of patients who were prescribed high doses of metformin and had no known contraindications.

Main Results:

• Both patients presented with severe lactic acidosis, elevated creatinine, and urea.
• Treatment involved intensive care, vasopressor support, ventilatory support, and continuous venovenous hemodiafiltration.
• Both patients showed progressive recovery and were discharged from the intensive care unit.

Conclusions:

• Severe lactic acidosis can occur in patients taking high doses of metformin, even without established contraindications.
• No other causative condition for lactic acidosis was identified in these cases.
• Lactic acidosis should be considered in the differential diagnosis for patients on metformin therapy.