Pharmacy Clinical Pearl of the Day: Metformin and Kidney Function in Diabetes

How should pharmacists manage a patient with diabetes on metformin with GFR below 30?

Clinical Pearl of the Day:

If a patient has diabetes, with metformin onboard as a treatment option, and GFR (kidney function) is below <30, metformin should be discontinued.

Explanation:

  • Do not use metformin among patients with an eGFR less than 30.
  • Do not start metformin among patients with an eGFR between 30 and 45.
  • Stop metformin if a patient’s eGFR drops less than at any point during therapy.
  • Complete a risk-benefit analysis of metformin if a patient’s eGFR drops to less than 45.
  • Because metformin is renally cleared, it may cause some concern about nephrotoxicity, especially lactic acidosis, in patients with impaired renal function.

Reference: Metformin and Renal Function (diabeteseducator.org)