SAN DIEGO, CA—High-dose oral vancomycin does not improve clinical outcomes over 125mg low dose vancomycin therapy among adult patients with nosocomial Clostridium difficile infection (CDI), according to retrospective study findings reported at IDWeek 2015

“Vancomycin dose was not found to impact clinical cure,” reported lead study author Benjamin J. Ereshefsky, PharmD, Philadelphia College of Pharmacy, University of the Sciences, Philadelphia, PA.

Despite current clinical guidelines that recommend an oral vancomycin dose of 125mg every 6 hours for severe CDI—and 600mg every 6 hours for severe and complicated CDI—doses in clinical practice vary, and commonly include 125mg, 250mg, or 500mg for patients with varying levels of CDI severity.

However, “few studies have addressed clinical outcomes with low- and high-dose oral vancomycin,” Dr. Ereshefsky noted.

To help address the evidence gap, the researchers conducted a records review to evaluate clinical outcomes associated with low- (125mg) and high-dose (250mg or 500mg) oral vancomycin among 111 adult patients admitted to Cooper University Hospital with a first documented episode of CDI between January 1, 2011, and September 1, 2014.

Patients were excluded if they had received ≥6 doses or 48 hours of metronidazole before starting vancomycin, or if they had recurrent episodes of CDI, Dr. Ereshefsky reported.

Of the 111 patients in the study, 78 (70.3%) received low dose vancomycin and 33 (29.7%) received high-dose vancomycin.

Clinical outcomes were assessed as complete or partial cure noted at end of treatment or hospital discharge. Secondary outcomes included 90-day recurrence and readmission rates, 30-day all-cause mortality, and time to resolution of diarrhea, Dr. Ereshefsky noted.

When complete or partial cure between treatment groups was compared, equivalence was met, 70.5% for vancomycin 125mg vs. 72.7% for vancomycin 250mg/500 mg (P=0.03), he reported. Logistic regression identified baseline albumin levels (2.63) and no ICU admission (7.93) as being associated with complete or partial cure, whereas female gender was negatively associated with complete or partial cure (0.31).

Leukocytosis at end of treatment (18.9) and concurrent bacteremia (52.6) were associated with 30-day mortality.

“Vancomycin dose was not associated with higher 90-day recurrence-readmission rate or increased 30-day mortality,” he concluded.