Table 1

Proposed recommendations for use of metformin based on eGFR

eGFR level (mL/min per 1.73 m2)Action
≥60No renal contraindication to metformin
Monitor renal function annually
<60 and ≥45Continue use
Increase monitoring of renal function (every 3–6 months)
<45 and ≥30Prescribe metformin with caution
Use lower dose (e.g., 50%, or half-maximal dose)
Closely monitor renal function (every 3 months)
Do not start new patients on metformin
<30Stop metformin
  • Additional caution is required in patients at risk for acute kidney injury or with anticipated significant fluctuations in renal status, based on previous history, other comorbidities, or potentially interacting medications.