What are the issues of using contrast in patients on metformin?
• None for MRI contrast.
• For IV iodinated contrast:
Metformin in isolation is not considered a risk factor for contrast-induced nephropathy.
However, patients who develop acute kidney injury (AKI) while taking metformin may be susceptible to the development of lactic acidosis.
Per the Metformin package insert (perhaps overly cautious), metformin should be stopped at the time of contrast injection and withheld for 48 hours.
Per ACR contrast guidelines:
• In patients with no evidence of AKI and with estimated glomerular filtration rate (eGFR) ³³ 30 mL/min per 1.73 m 2 , there is no need to discontinue metformin either prior to or following the IV administration of iodinated contrast media, nor is there an obligatory need to reassess the patient’s kidney function following the test or procedure.
