TABLE 4.

VISN 17–Accepted eGFR-Based Dosing Recommendations*

eGFR (mL/min/1.73 m2)Action
≥60No renal contraindication to metformin
Monitor renal function annually
45–59Continue metformin use
Increase monitoring of renal function (every 3–6 months)
30–44Prescribe metformin with caution
Use lower dose (half-maximal dose)
Closely monitor renal function (every 3 months)
Do not start new patients on metformin
<30Discontinue metformin
  • Additional caution is required in patients at risk for acute kidney injury or with anticipated significant fluctuations in renal status based on history, other comorbidities, or potentially interacting medications.

  • * eGFR calculated using the formula eGFR = 175 × [SCr] – 1.154 × [age] – 0.203 × [0.742] if female × [1.210] if black. Adapted from Inzucchi et al. (8).