[Fatal autointoxication with metformin]

A 39-year-old woman with type-2 diabetes mellitus presented with metabolic acidosis due to an attempted suicide with metformin. Despite treatment with activated charcoal and laxation, she experienced cardiac arrest, which required resuscitation. After transfer to another hospital, she was treated with high-volume continuous venovenous haemofiltration. However, she died due to multiple organ failure. Metformin is the most widely used oral antidiabetic agent in the world and the first-choice treatment for patients with type-2 diabetes mellitus. Metformin overdose can cause lactic acidosis, which usually manifests as abdominal pain, vomiting and diarrhoea. Although rare, metformin-associated lactic acidosis carries a high mortality risk. The treatment of choice is immediate haemodialysis and orally administered activated charcoal. If a patient treated with metformin presents with metabolic acidosis, lactic acidosis due to metformin overdose should be suspected and appropriate treatment should be initiated immediately.