A Case of Metformin-associated Lactic Acidosis

A 76-year-old female admitted with nausea, anorexia, vague abdominal pain, and malaise. Her past medical history included an 15-year history of type 2 diabetes mellitus and hypertension. She had been taking metformin, glipizid, and amlodipine for past 2 years. One week previously, she underwent gastroscopy to evaluate epigastic pain, and she was diagnosed Helicobacter pylori positive duodenal ulcer, for which she was treated with amoxicillin, clarithromycin, and omeprazole. At admission, laboratory test revealed lactic acidosis (pH 7.23, bicarbonate 8.3 mEq/L, and lactate 5.51 mmol/L) and acute renal failure with a serum creatinine of 7.4 mg/dL. We diagnosed meformin-associated lactic acidosis and the patient made a complete recovery following therapy with bicarbonate-based hemodialysis and supportive care. It is the first report of metformin-associated lactic acidosis in Korea.