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 highmortality rate (≥50%). Hypoxia has been suggested to contribute to metformin-associatedlactic acidosis (MALA) in 90% of patients developing this condition. In susceptible patientssuch as those with renal insufficiency, the level of plasma metformin is increased particularlyafter exposure to iodinated contrast media (ICM). One major concern in patients with renalinsufficiency is to adjust the metformin dose based on the renal functional capacity prior to ICMexamination. In this review, we assessed metformin tolerable threshold in diabetic patients withrenal failure. We also reviewed metformin withdrawal criteria in patients with chronic kidneydisease (CKD) exposed to intravenous ICM during angiography. Our results indicated that inpatients with insufficient renal function (i.e. 30< estimated glomerular filtration rate(eGFR) <60and 30<eGFR<45 mL/min/1.73 m2), or those with acceptable renal function (eGFR ≥60 mL/min/1.73 m2) and concomitant comorbidities, the decision to withhold or reinitiate metforminshould be based on patient’s medical condition.