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/MIC_BMD ratio of 400 to 600 (assuming a vancomycin MIC_BMD 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 MIC_BMD 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/MIC_BMD ratio of 400 to 600 (assuming a vancomycin MIC_BMD 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 MIC_BMD 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 MIC_BMD 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 MIC_BMD 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