UCSFMC Adult Vancomycin Dosing and Monitoring Recommendations

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Vancomycin has demonstrated dose-response and dose-toxicity relationships with a relatively narrow therapeutic index. Thus, careful dosing and monitoring is warranted.

►INITIAL DOSING

Because of vancomycin's relatively long half-life, administration of a loading dose when initiating vancomycin may be beneficial in more rapidly achieving effective concentrations. 

Vancomycin loading doses should be considered for patients who have severe sepsis or with complicated infections (e.g. endocarditis, meningitis, nosocomial pneumonia)

Loading doses are based on a patient's total body weight without need for determining vancomycin clearance.  A dose of approximately 25mg/kg with a maximum dose of 2000mg is suggested, or the table below can be used.

Total Body Weight (Kg)  

45-65 kg

65-85 kg

>85 kg

Loading dose

 

1000mg IV x1

1500mg* IV x1

2000mg* IV x1

 

*For loading doses >1000mg, to expedite administration of the loading dose the initial load should be ordered as 1000mg dose given over 1 hour, followed immediately by 500mg over 30 minutes or 1000mg over 1 hour, as appropriate.

►MAINTENTANCE DOSING

Maintenance dosing of vancomycin requires estimation of the patient's creatinine clearance and body weight. The vancomycin dosing nomogram below can guide selection of maintenance doses.

 

 CrCl (mL/min)

Total Body Weight (kg)
<60 60-80 81-100 >100
>90 750mg IV q8h

1000mg IV q8h

1250mg IV q8h

1500mg IV q8h

50-90

750mg IV q12h 1000mg IV q12h 1250mg IV q12h 1000mg IV q8

15-49

750mg IV q24h 1000mg IV q24h 1250mg IV q24h 1500mg IV q24h

<15

10-15mg/kg IV x1, then redose according to levels

Consultation with clinical pharmacy is recommended for patients with serious infections, obesity, or unstable renal function.  For patients on hemodialysis, see Dose Recommendations for Patients on Intermittent & Continuous Hemodialysis

Alternatively, pharmacokinetic models can be used to estimate predicted vancomycin levels based on patient-specific parameters, using the UCSF Adult Vancomycin Dosing Calculator (Excel file for download)

►MONITORING

There is moderate evidence for a benefit of performance of vancomycin therapeutic drug monitoring (TDM) on toxicity, and weak evidence supporting its role in effective therapy. 

Indications for vancomycin TDM

-New vancomycin starts with anticipated duration of vancomycin therapy >3 days

-Patients currently receiving vancomycin with changes in renal function, concern for toxicity, or concern for therapeutic failure

Timing of vancomycin TDM

Approximately half of all vancomycin levels at UCSFMC are drawn incorrectly with respect to timing of the drug.  These incorrect levels are difficult or impossible to interpret and may cause patients harm by leading to inappropriate dose adjustments.

-Vancomycin levels should be drawn close to steady-state.  In most cases this can be achieved by drawing a vancomycin trough level before the fourth dose of a new start or change in dose.  In some circumstances drawing a level before the third dose may be reasonable, with the understanding the true steady-state level may be higher.

-Vancomycin trough levels should ideally be drawn immediately before administration of the fourth dose (within 30 minutes of the dose is acceptable), assuming the dose is given at its regular dosing interval (e.g. the fourth dose of a vancomycin 1g q12h regimen is administered 12 hours after the prior dose). 

-Vancomycin peak levels are rarely indicated but may be useful in patients with complex pharmacokinetics.  When indicated, they should be drawn 1 hour after the end of the infusion.

Interpretation of vancomycin levels

Data supporting the relationship of vancomycin exposure to outcomes is strongest for patients with MRSA bacteremia or pneumonia.  Higher vancomycin trough levels are associated with an increased risk of nephrotoxicity.

Indication Recommended Vancomycin Trough Range

Severe Infections including:

   -MRSA pneumonia, bacteremia, osteomyelitis (ID consult recommended)

   -CNS infections or endocarditis

    -empiric therapy in patients with severe sepsis & septic shock

 

15-20 mg/L

Uncomplicated Infections including:

    -skin & soft tissue infections in clinically stable patients, bone & joint infections (not due to MRSA)

 

10-20 mg/L

-If trough levels are substantially below the target range (e.g. <5 mg/L), consultation with ID or ID pharmacy is recommended.  A new loading dose or alternative therapy may be required.

-If trough levels are 20-25 mg/L, a dosage decrease or interval change should be considered if clinically appropriate. 

-If trough levels are 26-34 mg/L, decrease the dose or change the interval and consider holding vancomycin, rechecking a vancomycin level, and re-initiating at a new dose when the vancomycin level is within the therapeutic range.

-If trough levels are >35 mg/L, hold vancomycin, check a vancomycin level and SCr q12h, and restart with a new vancomycin regimen when the level is within the therapeutic range

The UCSF Adult Vancomycin Dosing Calculator (Excel file for download) can also be used to develop revised dosing regimens based on vancomycin levels obtained.