Maintenance Dosage Fraction of an Antibiotic Based on Estimated Drug Clearance

normal drug clearance =

= ((normal renal clearance) + (normal nonrenal clearance))

In the presence of pure renal disease, nonrenal clearance is unaffected (ideally).

Renal drug clearance is (ideally) directly proportional to creatinine clearance.

If normal renal creatinine clearance is 100 mL/min then:

estimated drug clearance =

= ((estimated renal clearance) + (normal nonrenal clearance))

where:

• estimated renal clearance =

= (normal renal clearance for drug) * ((calculated creatinine clearance) / (100 mL/min))

The dose of drug for patient with a degree of renal insufficiency =

= (regular maintenance dose) * ((estimated drug clearance) / (normal drug clearance))

Renal and Nonrenal Clearances for Some Antibiotics