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.
0 - 10 eGFR
2g IV q24h
10 - 50 eGFR
3-4g IV daily divided q8-12h
2g IV q8h
0.5-2g IV load then 500mg IV q12h
2g IV load then 1g IV q6h