What are the estimated GFR thresholds that limit SGLT2 inhibitors?

What are the estimated GFR thresholds that limit SGLT2 inhibitors?

• A. eGFR <60 mL/min/1.73 m2
• B. eGFR <80 mL/min/1.73 m2
• C. eGFR <50 reduces safety/efficacy and eGFR <30 not recommended
• D. eGFR <20 contraindicated

Answer: (C)

SGLT2 inhibitors work best when the kidneys can filter glucose and deliver it to the proximal tubule to be reabsorbed. As eGFR falls, the amount of filtered glucose declines, so the drug has less substrate to act on, and its glucose-lowering effect diminishes. At the same time, reduced kidney function can amplify risks such as volume depletion and electrolyte disturbances, narrowing the safety margin. That’s why the threshold thinking is that efficacy and safety are both reduced when eGFR drops below about 50, and initiation is not recommended when eGFR falls below about 30. In other words, below 50 you should be cautious because benefits wane and risks rise; below 30 the use is generally not advised.

SGLT2 inhibitors work best when the kidneys can filter glucose and deliver it to the proximal tubule to be reabsorbed. As eGFR falls, the amount of filtered glucose declines, so the drug has less substrate to act on, and its glucose-lowering effect diminishes. At the same time, reduced kidney function can amplify risks such as volume depletion and electrolyte disturbances, narrowing the safety margin.

That’s why the threshold thinking is that efficacy and safety are both reduced when eGFR drops below about 50, and initiation is not recommended when eGFR falls below about 30. In other words, below 50 you should be cautious because benefits wane and risks rise; below 30 the use is generally not advised.