In the setting of rapidly improving/worsening renal function, calculations of eGFR are inaccurate, and dosing should be based on estimated renal function instead.
If worsening renal function, actual GFR is likely lower than calculated.
If improving renal function, actual GFR is likely higher than calculated eGFR.
Not On Dialysis (eGFR)
500 mg PO daily to BID
500 mg PO BID to TID
500 mg PO TID to QID
500 - 1000 mg PO QID