Vancomycin Advanced AUC Calculator
Co-developed by
Matthew Girgis, PharmD, BCIDP trained in Boston, currently
fighting drug resistant bugs in Toronto, Canada.
Dr. Girgis recently published an article in Contagion Live (Feb 2023) on the implementation of Vancomycin AUC Dosing.
For single level dosing enter data under trough level below.
Also include current dose and interval in the levels section if dosing
by levels.
AUC Target:
0-24
Age:
Sex:
Serum Creatinine:
Height:
Weight:
Some hospitals have requested the option to manually enter the
CrCL:
mL/min
CrCL obesity adjustment calculation:
Elimination rate
constant: Background information
Volume of Distribution:
Select Vd:
L/kg
- Normal = 0.65
- Obese =
0.5
- Dehydrated = 0.6
- Overhydrated = 0.7-0.85
- Septic
Shock/ICU/Trauma = 0.7-0.75
- Pregnant in 3rd Trimester or <48h post
partum = 0.7
Desired Peak:
mcg/ml Desired Trough:
mcg/ml
Infusion time (ti):
Info
250mg - 1000mg = infused over 60 minutes
1250mg and 1500mg = infused over 90 minutes
1750mg and 2000mg = infused over 120 minutes
[
AUC guided recommendations will appear on the results
page]
References
This latest version is based on a comprehensive review of the most recent pharmacokinetic textbooks. Some of the sources used are listed
here
- Bauer LA. The Aminoglycoside Antibiotics. In Bauer LA, ed. Applied
Clinical Pharmacokinetics. 2nd ed. New York, NY: McGraw Hill Medical;
2008:97-206.
- Bauer LA. Vancomycin. In Bauer LA, ed. Applied Clinical
Pharmacokinetics. 2nd ed. New York, NY: McGraw Hill Medical; 2008:207-298.
- Burton ME, Shaw LM, Schentag JJ, Evans WE. Applied Pharmacokinetics &
Pharmacodynamics: Principles of Therapeutic Drug Monitoring. 4th ed.
Philadelphia: Lippincott Williams & Wilkins; 2006.
- DiPiro JT, Spruill WJ, Wade WE, Blouin RA, Pruemer JM. Concepts in Clinical
Pharmacokinetics, (5th Edition) 2010. American Society of Health Systems
Pharmacist, Bethesda, MD.
- Murphy JE. Aminoglycosides. In: Murphy JE, ed. Clinical Pharmacokinetics, 4th
ed. Bethesda, MD: American Society of Health-System Pharmacists, 2008:27-60.
- Winter ME. Basic clinical pharmacokinetics. 5th ed. Baltimore: Lippincott
Williams and Wilkins; 2010.
- Rybak MJ, Le J, Lodise TP,Levine DP, Bradley JS, Liu C, et al.
Therapeutic monitoring of vancomycin: A revised consensus guideline
and review of 1the American Society of Health-System Pharmacists,
the Infectious Diseases Society of America, the Pediatric Infectious
Diseases Society and the Society of Infectious Diseases Pharmacists.
Accessed: May 2019. [Link]
- Winter MA, Guhr KN, Berg GM. Impact of various body weights and
serum creatinine concentrations on the bias and accuracy of the
Cockcroft-Gault equation. Pharmacotherapy 2012; 32: 604-612 [PMID:
22576791 DOI: 10.1002/j.1875-9114.2012.01098.x]
Quotes: [Largest study so far....total of
3678 patients]
Regarding Salazar equation: This equation,
however, was not consistently shown in studies to be a
superior predictor of renal function. It is not widely used in
clinical practice and has not been validated in
pharmacokinetic studies. In addition, the Salazar-Corcoran
equation is not recognized by the National Kidney Foundation.
Regarding CG -LBW equation: Our findings do
not support those conclusions and are different from a recent
investigation of Clcr in 54 morbidly obese patients that found
that adjusting an obese patient's weight to a fat-free weight
or lean body weight predicted a Clcr calculated with the C-G
equation without bias. Notably,
our study included 2065 obese or morbidly obese patients, far
more than other published studies.
Conclusions: An unbiased C-G Clcr can be
calculated using actual body weight in underweight patients
and ideal body weight in patients of normal weight. Using
ABW0.4 for overweight, obese, and morbidly obese patients
appears to be the least biased and most accurate method for
calculating their C-G Clcr. Rounding Scr in patients with low
Scr did not improve accuracy or bias of the Clcr calculations. |
Vancomycin Monitoring (ASHP 2020)
See source below for the complete guidelines.
"In patients with suspected or definitive serious MRSA infections, an individualized target of the AUC/MICBMD ratio of 400 to 600 (assuming a vancomycin MICBMD of 1 mg/L) should be advocated to achieve clinical efficacy while improving patient safety (A-II). Doses of 15 to 20 mg/kg (based on actual body weight) administered every 8 to 12 hours as an intermittent infusion are recommended for most patients with normal renal function when assuming a MICBMD of 1 mg/L (A-II). In patients with normal renal function, these doses may not achieve the therapeutic AUC/MIC target when the MIC is 2 mg/L."
"In patients with suspected or definitive serious MRSA infections, an individualized target of the AUC/MICBMD ratio of 400 to 600 (assuming a vancomycin MICBMD of 1 mg/L) should be advocated to achieve clinical efficacy while improving patient safety (A-II). Doses of 15 to 20 mg/kg (based on actual body weight) administered every 8 to 12 hours as an intermittent infusion are recommended for most patients with normal renal function when assuming a MICBMD of 1 mg/L (A-II). In patients with normal renal function, these doses may not achieve the therapeutic AUC/MIC target when the MIC is 2 mg/L."
"Based on current national vancomycin susceptibility surveillance data, under most circumstances of empiric dosing, the vancomycin MIC should be assumed to be 1 mg/L. When the MICBMD is >1 mg/L, the probability of achieving an AUC/MIC target of ≥400 is low with conventional dosing; higher doses may risk unnecessary toxicity, and the decision to change therapy should be based on clinical judgment. In addition, when the MICBMD is <1 mg/L, we do not recommend decreasing the dose to achieve the AUC/MIC target. It is important to note the limitations in automated susceptibility testing methods, including the lack of precision and variability in MIC results depending on method used (B-II)."
"Trough-only monitoring, with a target of 15 to 20 mg/L, is no longer recommended based on efficacy and nephrotoxicity data in patients with serious infections due to MRSA (A-II). There is insufficient evidence to provide recommendations on whether trough-only or AUC-guided vancomycin monitoring should be used among patients with noninvasive MRSA or other infections."
"A vancomycin loading dose of 20 to 25 mg/kg using actual body weight, with a maximum dose of 3,000 mg, may be considered in obese adult patients with serious infections (B-II). Initial maintenance doses of vancomycin can be computed using a population PK estimate of vancomycin clearance and the target AUC in obese patients. Empiric maintenance doses for most obese patients usually do not exceed 4,500 mg/day, depending on their renal function (B-II). Early and frequent monitoring of AUC exposure is recommended for dose adjustment, especially when empiric doses exceed 4,000 mg/day (A-II). Measurement of peak and trough concentrations is recommended to improve the accuracy of vancomycin AUC estimation and maintenance dose optimization in obese patients, aligning with recommendations 2 and 5 for nonobese adults."
Source: Rybak MJ, Le J, Lodise TP, Levine DP, et al. Therapeutic monitoring of vancomycin for serious methicillin-resistant Staphylococcus aureus infections: A revised consensus guideline and review by the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists. Am J Health Syst Pharm. 2020 May 19;77(11):835-864. doi: 10.1093/ajhp/zxaa036. PMID: 32191793.
[BMD]- MIC determined by broth microdilution
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