Antibiotic Use in Renal Impairment

Introduction to Antibiotic Selection

The American College of Cardiology and other guideline societies recommend prioritizing antibiotics that are hepatically metabolized and require no dose adjustment, such as isoniazid, rifampin, doxycycline, and aztreonam, for patients with impaired renal function 1

Isoniazid and rifampin can be used at conventional doses regardless of renal function because they are hepatically metabolized 1
Ethionamide is not cleared by the kidneys and requires no adjustment, and is not removed by hemodialysis 1

Piperacillin/Tazobactam is safe with dose adjustment based on creatinine clearance, according to the World Journal of Emergency Surgery 2, 1
Levofloxacin requires substantial dose reduction, with 250 mg once daily for CrCl 20-49 mL/min 1
Ciprofloxacin is safe with dose adjustment, with 400 mg every 8 hours for normal function, and adjusted intervals for impairment 2
Vancomycin requires careful monitoring of trough levels to avoid further renal damage, with a target of 10-15 mcg/mL, and adjustment to achieve 1-hour serum concentration of 30-45 mcg/mL 3, 1

Interval extension rather than dose reduction should be used for concentration-dependent antibiotics, such as fluoroquinolones and aminoglycosides, to maintain peak bactericidal activity 4
The Infectious Diseases Society of America recommends using interval extension rather than dose reduction for concentration-dependent antibiotics 4

For CrCl 30-50 mL/min, trimethoprim-sulfamethoxazole should be reduced to half dose, and levofloxacin should be given 750 mg every 48 hours 4
For CrCl <30 mL/min or hemodialysis, isoniazid, rifampin, pyrazinamide, and ethambutol require specific dose adjustments 1

Nitrofurantoin is contraindicated when CrCl <30 mL/min 1
Aminoglycosides should be avoided in CKD patients due to nephrotoxicity risk, except for single-dose therapy in simple cystitis, and require careful monitoring and extended dosing intervals if used 4, 1

Antibiotics should be administered after hemodialysis to prevent drug removal during dialysis and facilitate directly observed therapy 4
Pyrazinamide should be given 25-30 mg/kg after dialysis 4

Therapeutic drug monitoring is mandatory for aminoglycosides and vancomycin 1
Regular assessment of renal function during antibiotic therapy is necessary 1
Monitoring for signs of drug toxicity is crucial, especially with narrow therapeutic window drugs 1
For gentamicin, target 1-hour serum concentration of 3 mcg/mL and trough of <1 mcg/mL in normal renal function, and adjust dosing intervals in mild renal impairment 3

Hepatically-metabolized drugs are not completely safe in renal failure, as toxicity risk is increased through altered metabolism 4
Once-daily aminoglycoside dosing should not be used for endocarditis, and multiple daily divided doses are required until more data is available 3
Vancomycin should not be combined with gentamicin unless absolutely necessary, due to increased risk of ototoxicity and nephrotoxicity 3
Doses of concentration-dependent antibiotics should not be reduced, but instead intervals should be extended to maintain bactericidal peaks 4