Metformin overdose: An unusual cause of severe metabolic acidosis

Abstract

Metformin is commonly used in the treatment of type 2 diabetes mellitus (DM). Severe lactic acidosis is a rare side effect of this drug. We present a 45-year-old man who deliberately took 30 g of metformin, presumably with suicidal intent. He had not eaten the previous night and presented with altered sensorium and recurrent seizures. He had profound metabolic acidosis at presentation with a pH of 7.06 and a low blood sugar of 44 mgs/dl. The patient was admitted in intensive care unit (ICU) with the suspicion of metformin-associated lactic acidosis. He developed irreversible renal failure, neurological deterioration and anemia. Despite of daily intensive hemodialysis and other supportive measures the patient expired 14 days later. Metformin overdose with renal failure and severe lactic acidosis have high mortality; hence, urgent medical consultation and treatment can be life saving in these patients.