Improving vancomycin prescription in critical illness through a drug use evaluation process: a weight-based dosing intervention study

Abstract Vancomycin is currently recommended as first-line therapy for many meticillin-resistant Staphylococcus aureus (MRSA) infections. Recent guidelines have advocated loading doses (25–30mg/kg) in critically ill patients in order to achieve therapeutic concentrations rapidly. However, weight-based loading doses are still not widely practised. A drug use evaluation was performed to improve the appropriateness of vancomycin initial doses in a population of critically ill adults. An educational intervention incorporating a vancomycin dosing protocol was carried out. Data were collected pre and post intervention. Vancomycin exposure [area under the concentration–time curve (AUC)] in the first 24h was determined using serum concentrations and the Bayesian software TCIWorks. Initial vancomycin doses and exposures were compared between the pre- and post-intervention groups using χ 2 and Mann–Whitney tests. A total of 111 vancomycin courses were analysed in the pre-intervention ( n =80) and post-intervention ( n =31) groups. Patients in the post-intervention group had significantly higher median weight-based initial doses (20.0mg/kg vs. 12.5mg/kg; P P