Laboratory-Confirmed Metformin-Associated Lactic Acidosis

Introduction Metformin is considered the first line oral hypoglycaemic agent for the treatment of type 2 diabetes. We report three cases of prospectively identified laboratory confirmed metformin-associated lactic acidosis admitted to our intensive care unit. Case 1 72-year-old female presented with lactic acidosis; pH 6.7, lactate 22.6mmol/L with elevated Metformin levels of 4.9mg/L. Case 2 56-year-old female presented with lactic acidosis; pH 7.2 and lactate 14.8mmol/L. Metformin levels elevated at 3.9mg/L. Case 3 72-year-old female presented with lactic acidosis, pH 6.95 and lactate of 27.6mmol/L with elevated Metformin levels of 48.7mg/L. Results All three cases were admitted to the intensive care unit to receive supportive care. Despite CVVHD, two patients died. Discussion Metformin is considered the first line oral hypoglycaemic agent. Confirmation of this diagnosis often proves difficult due to the scarcity of laboratory testing. Our case series highlights the issues of inappropriate prescription in specific patient populations.