Suicide commitment with metformin: our experience with five cases.

Biguanides can function as oral antihyperglycemic drugs. They were used for diabetes mellitus or prediabetes treatment over the last nine decades, but they lost their popularity in 1970s because of phenformin and regained with metformin. For metformin, the most common side effects are diarrhea and dyspepsia, occurring in up to 30% of patients. The most important and serious side effect is lactic acidosis. Phenformin was removed from the markets before 1970, because it caused lactic acidosis in 40-65 patients in 100,000 patient-years. Metformin causes lactate accumulation only in patients who have hepatic failure, renal failure or in patients who attempt suicide with high dosage of drugs. In this report, we present five patients who used high doses of metformin for suicide attempt.