From the Guidelines
Patients undergoing Renal Replacement Therapy (RRT) require higher doses of certain antibiotics, including vancomycin, gentamicin, and ceftazidime, to ensure effective treatment and prevent underdosing due to enhanced drug clearance during RRT. The dosing of these antibiotics is crucial in patients undergoing RRT, as the treatment can significantly affect the pharmacokinetics of these medications 1. Some key antibiotics that require dose adjustments in RRT patients include:
- Vancomycin: a 20-mg/kg loading dose infused during the last hour of the dialysis session, and then 500 mg during the last 30 min of each subsequent dialysis session 1
- Gentamicin (or tobramycin): 1 mg/kg, not to exceed 100 mg after each dialysis session 1
- Ceftazidime: 1 g iv after each dialysis session 1
- Cefazolin: 20 mg/kg iv after each dialysis session 1 It is essential to note that the specific dose adjustment depends on the type of RRT, filter type, blood and dialysate flow rates, and the antibiotic's pharmacokinetic properties 1. Regular therapeutic drug monitoring is crucial when available to ensure optimal antibiotic concentrations and effective treatment while minimizing toxicity. In clinical practice, the choice of antibiotic and dosing regimen should be individualized based on the patient's specific needs, the suspected or confirmed pathogen, and local antibiogram data 1.
From the FDA Drug Label
DOSAGE TABLE FOR VANCOMYCIN IN PATIENTS WITH IMPAIRED RENAL FUNCTION (Adapted from Moellering et al. 1) Creatinine ClearancemL/minVancomycin Dosemg/24 h 1001,545 901,390 801,235 701,080 60925 50770 40620 30465 20310 10155 The initial dose should be no less than 15 mg/kg, even in patients with mild to moderate renal insufficiency. The table is not valid for functionally anephric patients For such patients, an initial dose of 15 mg/kg of body weight should be given to achieve prompt therapeutic serum concentrations. The dose required to maintain stable concentrations is 1. 9 mg/kg/24 hr. In patients with marked renal impairment, it may be more convenient to give maintenance doses of 250 to 1,000 mg once every several days rather than administering the drug on a daily basis. In anuria, a dose of 1,000 mg every 7 to 10 days has been recommended
Vancomycin requires a higher dose in patients undergoing Renal Replacement Therapy (RRT), but the provided information does not directly state the dose for RRT patients. However, for functionally anephric patients, an initial dose of 15 mg/kg of body weight should be given to achieve prompt therapeutic serum concentrations, and the dose required to maintain stable concentrations is 1.9 mg/kg/24 hr 2.
From the Research
Antibiotics Requiring Higher Doses in RRT Patients
- Vancomycin: requires a higher dose in patients undergoing Renal Replacement Therapy (RRT) due to altered pharmacokinetics and pharmacodynamics 3, 4, 5, 6, 7
- Aminoglycosides: may require therapeutic drug monitoring (TDM) to control drug exposure in patients receiving RRT 3
- Beta-lactams: may require TDM to control drug exposure in patients receiving RRT 3
- Glycopeptides: may require TDM to control drug exposure in patients receiving RRT 3
- Linezolid: may require TDM to control drug exposure in patients receiving RRT 3
- Colistin: may require TDM to control drug exposure in patients receiving RRT 3
- Daptomycin: may require TDM in critically ill patients on RRT 3
- Fluoroquinolones: may require TDM in critically ill patients on RRT 3
- Tigecycline: may require TDM in critically ill patients on RRT 3
Factors Affecting Antibiotic Dosing in RRT Patients
- Residual renal function: affects antibiotic clearance and dosing requirements 6
- Comorbidities: may affect antibiotic pharmacokinetics and dosing requirements 6
- Severity of illness: may affect antibiotic pharmacokinetics and dosing requirements 6
- RRT modality: affects antibiotic clearance and dosing requirements 4, 5, 6, 7
- Filter patency: affects antibiotic clearance during CRRT 7