What is the appropriate vancomycin dosing regimen for a patient with a CrCl (creatinine clearance) of 120 and a weight of 64 kg?

Vancomycin Dosing for a 44-Year-Old Female with CrCl 120 mL/min and Weight 64 kg

For this 44-year-old female patient with CrCl 120 mL/min and weight 64 kg, the appropriate vancomycin dosing regimen is 15-20 mg/kg (960-1280 mg) every 8-12 hours, with a target trough concentration of 15-20 mg/L. 1

Initial Dosing Calculation

• Calculate dose based on actual body weight: 15-20 mg/kg × 64 kg = 960-1280 mg per dose 1
• For a patient with normal renal function (CrCl 120 mL/min), dosing interval should be every 8-12 hours 1
• A reasonable starting regimen would be 1 gram IV every 8-12 hours 1, 2
• For doses exceeding 1 gram, extend infusion time to 1.5-2 hours to minimize infusion-related reactions 1

Target Concentrations

• Target trough serum vancomycin concentration of 15-20 mg/L is recommended for serious infections 1
• This target range helps achieve the pharmacodynamic goal of AUC/MIC ≥400 when the MIC is ≤1 mg/L 1, 3
• Trough concentrations <10 mg/L should be avoided to prevent development of resistance 1

Monitoring Recommendations

• Obtain first trough level immediately before the fourth dose (at steady state) 1
• Draw trough levels 30 minutes before the next scheduled dose 1
• No need for peak concentration monitoring as it does not correlate with efficacy or toxicity 1
• Regular monitoring (at least weekly) is recommended for prolonged therapy 4

Dose Adjustments

• If the vancomycin MIC is ≥2 mg/L, target AUC/MIC ratio of ≥400 may not be achievable with conventional dosing and alternative therapies should be considered 1
• If trough levels are below target range, consider increasing the dose or decreasing the dosing interval 1
• If trough levels are above target range, consider decreasing the dose or increasing the dosing interval 1

Considerations for Toxicity

• Monitor renal function regularly during therapy 1
• Vancomycin-induced nephrotoxicity is defined as multiple (≥2-3) consecutive increases in serum creatinine (increase of 0.5 mg/dL or 50% increase from baseline) after several days of therapy without alternative explanation 1
• Higher trough concentrations (15-20 mg/L) may be associated with increased risk of nephrotoxicity 1

Clinical Pearls

• Individual pharmacokinetic adjustments may be necessary as currently available nomograms may not achieve target trough concentrations 1
• For patients with rapidly changing renal function, more frequent monitoring may be necessary 2
• The dosing formula based on creatinine clearance (ClVanco in L/h = [(CrCl × 0.689) + 3.66] × 0.06) can be used to estimate vancomycin clearance and optimize dosing 3
• Loading doses may be considered (25-30 mg/kg) in critically ill patients to rapidly achieve therapeutic concentrations 5