If estimated GFR is 30-60 mL/min/1.73 m2, what is recommended regarding metformin around a procedure?

• A. Continue metformin
• B. Hold metformin prior to procedure
• C. Stop metformin permanently
• D. Double the metformin dose before procedure

Answer: (A)

Metformin clearance depends largely on kidney function, so peri‑procedural decisions center on balancing the low risk of lactic acidosis with the importance of maintaining glycemic control. When the estimated GFR is in the 30–60 mL/min/1.73 m2 range, continuation of metformin around a procedure is generally appropriate if there are no additional risk factors for kidney injury. This level of renal function is not enough by itself to mandate stopping metformin, and stopping unnecessarily can lead to hyperglycemia and other complications. The key is to watch for factors that could worsen kidney function or cause dehydration or hypotension around the procedure, such as contrast exposure, volume loss, or acute illness; in those cases, hold or adjust as needed. In contrast, metformin is typically withheld only if there is a higher risk of lactic acidosis (for example, eGFR below 30) or when specific peri‑procedural factors (like iodinated contrast with dehydration risk) raise concern. Thus, for an eGFR 30–60, continuing metformin is the usual, safe approach unless there are procedure‑specific risks that would prompt temporary withholding.