Continuation or termination of metformin in diabetic patients exposed to iodinated contrast medium?

Lactic acidosis (LA) secondary to metformin administration is a rare incident with a very high mortality rate (≥50%). Hypoxia has been suggested to contribute to metformin-associated lactic acidosis (MALA) in 90% of patients developing this condition. In susceptible patients such as those with renal insufficiency, the level of plasma metformin is increased particularly after exposure to iodinated contrast media (ICM). One major concern in patients with renal insufficiency is to adjust the metformin dose based on the renal functional capacity prior to ICM examination. In this review, we assessed metformin tolerable threshold in diabetic patients with renal failure. We also reviewed metformin withdrawal criteria in patients with chronic kidney disease (CKD) exposed to intravenous ICM during angiography. Our results indicated that in patients with insufficient renal function (i.e. 30< estimated glomerular filtration rate(eGFR) <60 and 30