Metformin and Your CT
If your doctor allows, medications that contain metformin should be stopped on the day you have a CT scan or procedure that requires the use of iodine contrast material (radiology dye). This type of contrast, which is used in the veins, may affect your kidneys and how your body clears metformin from your system. Common medicines that contain metformin include:
Check with your doctor about whether it is OK for you to stop taking
medicine that contains metformin on the day of your scan or procedure.
Also, ask your health care provider if you should have your kidney
function checked before you restart your metformin medication.
Stop taking medicine that contains metformin on the day of your scan or procedure where contrast will be used. Restart your medicine 48 hours after your scan or procedure.