Evaluation of a vancomycin dosing regimen for patients on high flux hemodialysis: an observational study

Vancomycin is the mainstay antibiotic used in hemodialysis group due to high prevalence of methicillin resistant Staphylococcus Aureus. For years regimens of vancomycin in high flux hemodialysis (HFHD) patients were designed to achieve a pre-dialysis vancomycin concentration between 5-20 ug/mL. Recent guidelines increased the recommended pre-dialysis level to 15-20 ug/ml for health care associated infections, bacteremia and osteomyelitis. The purpose of this study was to determine if the loading dose (LD) before HFHD and the maintenance dose (MD) of vancomycin achieved a pre-dialysis concentration between 15-20 ug/ml on HFHD in-patients with a suspected infection. The second purpose was to predict an adequate vancomycin dosage to achieve the new recommended levels.

An observational prospective study on hospitalized adult patients on HFHD with evidence of infection treated with 1 gm LD of vancomycin and 500 mg MD. Plasma levels of vancomycin were measured before each HFHD for three consecutive times. Age, gender, weight at admission, blood flow rate, dialyzer flow rate, type of filter and HFHD length were evaluated.

Twenty-one patients met the inclusion criteria. All of them were treated with 1 gm LD of vancomycin and 500 mg MD protocol. The mean pre-dialysis concentration #1 was 10.8 ug/mL. The mean pre-dialysis concentration #2 was 13 ug/mL, and the mean pre-dialysis concentration #3 was 12 ug/mL. Only 36% of HFHD sessions achieved an adequate vancomycin level. A liner regression analysis predicted that a loading dose of 23 mg/kg LD and 8 mg/kg MD achieved the recommended pre-dialysis vancomycin concentration.

Current dose regimen of 1 gm LD and 500 mg MD of Vancomycin are not adequate to achieve recommended pre-dialysis level of 15-20 ug/mL for health care associated infections, bacteremia and osteomyelitis in most patients on HFHD. Based on our statistical analysis, we recommended that 23 mg/kg of LD and 8 mg/kg of MD would achieve an adequate vancomycin level.