Radcomics
Vol.2
Preparing for a Safe CT Scan: A Focus on Diabetes
Metformin
Management
The management of patients taking metformin should be guided by the following:
- Patients taking metformin are not at higher risk than other patients for post-contrast acute kidney injury.
- Iodinated contrast is a potential concern for furthering renal damage in patients with acute kidney injury, and in patients with severe chronic kidney disease (stage IV or stage V).
- There have been no reports of lactic acidosis following intravenous iodinated contrast medium administration in patients properly selected for metformin administration.
The Committee recommends that patients taking metformin be classified into one of two categories based on the patient’s renal function (as measured by eGFR).
Category I
In patients with no evidence of AKI and with eGFR ≥30 mL / min/1.73m2, there is no need to discontinue metformin either prior to or following the intravenous administration of iodinated contrast media, nor is there an obligatory need to reassess the patientʼs renal function following the test or procedure.
Category II
In patients taking metformin who are known to have acute kidney injury or severe chronic kidney disease (stage IV or stage V; i.e., eGFR< 30), or are undergoing arterial catheter studies that might result in emboli (atheromatous or other) to the renal arteries, metformin should be temporarily discontinued at the time of or prior to the procedure, and withheld for 48 hours subsequent to the procedure and reinstituted only after renal function has been re-evaluated and found to be normal.
Metformin and Gadolinium
It is not necessary to discontinue metformin prior to contrast medium administration when the amount of gadolinium--based contrast material administered is in the usual dose range of 0.1 to 0.3 mmol per kg of body weight.
ACR Manual on Contrast Media Version 2021
