Pharmacist and Physician Collaborative Practice Model Improves Vancomycin Dosing in an Intensive Care Unit

Abstract

Objective: A pharmacist and physician collaborative practice intervention to improve the initial dosing of vancomycin was implemented with the goal of decreasing the number of subtherapeutic first troughs and increasing the number of therapeutic troughs. Methods: Using the best available evidence, a nomogram was created to determine the initial vancomycin dose. The nomogram utilized actual bodyweight and glomerular filtration rate (eGFR) estimated with the MDRD4 equation. The dose was based on the 2009 ASHP/IDSA/SIDP guidelines, which recommended 15 - 20 mg/kg every 8 - 12 hours. Providers ordered “vancomycin IV dosed per pharmacy”. Results: The pre- (n = 75) and post-intervention (n = 108) cohorts had similar age, gender distribution, weight, and eGFR. The median total daily vancomycin dose was similar in pre- and post-intervention groups (2000 mg), although the median first trough was higher following the intervention (13.0 vs. 14.8 mcg/ml, p = 0.03). Following the intervention, the proportion of first troughs under 10 mcg/ml decreased (32% to 13%, p = 0.003), while the proportion of troughs in the 10 - 20 mcg/ml therapeutic range increased (50.7% vs. 69.4%, p = 0.01). There was no difference in the proportion of troughs over 20 mcg/ml (17.3% vs. 17.6%, p = 0.96). Conclusions: A multi-disciplinary intervention utilizing a nomogram-based pharmacy collaborative practice model significantly improves the proportion of therapeutic initial vancomycin troughs and decreases the number of subtherapeutic troughs by half.