Intoxication par la metformine : mécanismes de toxicité et prise en charge

Severe lactic acidosis is the major complication of metformin poisoning, either intentional or incidental. It usually occurs when a precipitating disease induces an acute renal failure resulting in the drug accumulation. Voluntary intoxication has been rarely reported. The effect of metformin on the mitochondrial respiratory function explains the increase in liver lactate production and the subsequent acidosis. Outcome of lactic acidosis is uniformly favorable after intentional metformin overdose provided the drug being removed by extrarenal support. The vital prognosis is mainly influenced by the occurrence of multiple organ dysfunction, and particularly an acute associated or drug-induced liver dysfunction. Bicarbonate hemodialysis is recommended to decrease metformin levels and correct acidosis. Sequential measurements of metformin levels during hemodialysis are consistent with a bicompartmental elimination pattern and a prolonged cumulative duration of hemodialysis needed to decrease metformin levels within the therapeutic normal range.