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)
IV formulation not recommended due to accumulation of vehicle (cyclodextrin), switch to oral. No dose modification needed.
IV - 6mg/kg IV q12h x 2 doses then 4mg/kg IV q12h PO - 400mg PO q12h x 2 doses then 200mg PO q12h Dose reduction may be required if low body weight
Intermittent Dialysis
IV therapy not recommended due to accumulation of cyclodextrin Oral dosing does not require modification in renal failure
Continuous Dialysis
6mg/kg IV q12h x 2 doses then 4mg/kg IV q12h