PURPOSE: The purpose of this investigation was to determine which dosing modality was clinically more efficient and safer in surgery patients treated for suspected or well-established methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. Additionally, cost analysis will be determined in the treatment of such infections. The primary objective was to determine the percent of treatment courses that achieve steady-state concentrations with a target drug serum concentration of 15-20mg/L.
METHODS: This study is a retrospective, single-center, observational study comparing intermittent vancomycin dosing (IIV) and continuous vancomycin infusion (CIV). Data collection was performed via hospital electronic medical record database and paper charts. Adult surgery patients being treated for suspected or well-established MRSA pneumonia were included. Exclusion criteria included: pregnant, < 18 years, ascites, cystic fibrosis, hemodialysis, renal dysfunction (CrCl< 30mL/min), or who had indications for vancomycin other than pneumonia.
RESULTS: One hundred twenty treatment courses (IIV=74 and CIV=46) were identified over a 6-month period. Treatment courses that achieved vancomycin levels at steady-state concentrations were evaluated (IIV=23 and CIV=33). The incidence of treatment courses that achieved a target serum drug concentration of 15-20mg/L with the first dose (8.7% vs 39.4%, respectively; p=0.01) differed between both groups. The mean (± SD) vancomycin levels achieved (9.5±5.6 vs 19.2±9.2mg/L, respectively; p<0.0001), number of levels drawn (1.4±0.7 vs 1.1±0.4, respectively; p=0.047), number of dose adjustments (0.4±0.7 vs 0.3±0.5, respectively; p=0.41), and total treatment cost ($103.00±69.90 vs $81.90±30.60) differed between both treatment courses except for number of dose adjustments. The incidence of nephrotoxicity (IIV=2.7% vs CIV=0%) was based on all treatment courses included in the study.
CONCLUSION: Continuous vancomycin infusion is more efficient at achieving the recommended target drug concentration, less expensive, and as safe as IIV.
CLINICAL IMPLICATIONS: Based on this study population, the recommended dose of 30 mg/kg/day for MRSA pneumonia does not achieve the target serum drug concentration of 15-20mg/L. CIV may be an alternative dosing modality; however a large, prospective, randomized control trial is needed to determine if this strategy achieves target concentrations.
DISCLOSURE: Ronald Sing, No Financial Disclosure Information; No Product/Research Disclosure Information