What is the dosage of Vancomycin (Vanco) for Continuous Renal Replacement Therapy (CRRT)?

From the Guidelines

Vancomycin dosing for patients on Continuous Renal Replacement Therapy (CRRT) should be initiated with a loading dose of 25-30 mg/kg actual body weight, followed by maintenance doses guided by therapeutic drug monitoring to achieve trough levels of 15-20 mg/L. The dosing strategy for vancomycin in CRRT patients is critical due to the increased volume of distribution and altered pharmacokinetics in critically ill patients 1. Key considerations include the patient's actual body weight, the specific CRRT modality, and the need for regular monitoring of vancomycin levels to adjust the dose and ensure adequate antimicrobial coverage while minimizing toxicity risks.

Key Considerations for Vancomycin Dosing in CRRT

• Loading dose: 25-30 mg/kg actual body weight to rapidly achieve therapeutic levels 1
• Maintenance dose: Guided by therapeutic drug monitoring, aiming for trough levels of 15-20 mg/L 1
• Therapeutic drug monitoring: Essential to adjust the dose based on vancomycin levels, patient's clinical response, and changes in CRRT settings
• CRRT modality: Affects vancomycin elimination, with CVVH, CVVHD, and CVVHDF having different impacts on drug clearance 1
• Regular monitoring: First level typically drawn before the third or fourth dose, with subsequent adjustments based on levels and clinical response

Rationale for Dosing Strategy

The increased volume of distribution in critically ill patients, particularly those on CRRT, necessitates a higher loading dose to achieve therapeutic levels quickly 1. The goal of achieving trough levels of 15-20 mg/L is based on the concentration-dependent efficacy of vancomycin and the need to optimize clinical outcomes 1. Regular monitoring and adjustments are crucial to balance the risk of underdosing, which can lead to treatment failure, and the risk of overdosing, which can result in nephrotoxicity and ototoxicity.

Clinical Implications

The dosing strategy outlined above is designed to maximize the effectiveness of vancomycin therapy in CRRT patients while minimizing adverse effects. By prioritizing therapeutic drug monitoring and adjusting the dose based on individual patient factors, clinicians can optimize vancomycin levels and improve patient outcomes 1. This approach is consistent with the principles of pharmacokinetically optimized antimicrobial dosing strategies in critically ill patients with sepsis and septic shock 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 dosage of Vancomycin for patients undergoing Continuous Renal Replacement Therapy (CRRT) is not explicitly stated in the provided drug label. However, for patients with impaired renal function, the dosage can be calculated using the provided table based on creatinine clearance.

• 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.
• 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 2.

From the Research

Vancomycin Dosage for Continuous Renal Replacement Therapy (CRRT)

• The optimal vancomycin dosage for patients receiving CRRT is not well established, but several studies have investigated this topic 3, 4, 5, 6, 7.
• A study published in 2023 found that 50% of ICU patients on CRRT showed subtherapeutic vancomycin concentrations 24 hours after starting therapy, highlighting the need for optimization of vancomycin dosage during CRRT therapy 3.
• Another study from 2023 developed a population pharmacokinetic model of vancomycin that incorporates daily urine volume to better describe the elimination of vancomycin in critically ill patients receiving CRRT, and recommended a maintenance dosage regimen of 750 mg q12h for patients with anuria or oliguria 4.
• A 2019 study used population pharmacokinetic modeling and simulations to determine the optimal loading and maintenance doses for continuous infusion of vancomycin in critically ill patients, and found that large loading and maintenance doses of vancomycin are generally needed in critically ill patients 5.
• The VANCTIC Study, published in 2019, found that only 15.71% of critically ill trauma patients achieved an initial therapeutic vancomycin trough, and that augmented renal clearances were observed in these patients 6.
• A Monte Carlo simulation study published in 2019 aimed to determine the optimal vancomycin dosing regimens for critically ill patients with acute kidney injury during CRRT, and recommended regimens of 1.75 grams every 24 hours and 1.5 grams loading followed by 500 mg every 8 hours for empirical therapy of an MRSA infection with expected MIC ≤1 mg/L 7.

Key Findings

• Vancomycin pharmacokinetics are altered in critically ill patients receiving CRRT, leading to inadequate serum levels 3, 4, 5, 6, 7.
• Large loading and maintenance doses of vancomycin are generally needed in critically ill patients 5.
• Daily urine volume is a significant covariate of vancomycin clearance in critically ill patients receiving CRRT 4.
• Augmented renal clearances are observed in critically ill trauma patients, which can affect vancomycin dosing 6.
• Monte Carlo simulation can be used to determine the optimal vancomycin dosing regimens for critically ill patients with acute kidney injury during CRRT 7.