Erica Reed

Ensuring appropriate dosing of medications is an essential practice of clinical pharmacists. Dose adjustments in the setting of decreased renal function are common but may also be warranted for patients with supraphysiologic or augmented renal clearance (ARC). Conventional estimates of creatinine clearance using only serum creatinine may not be accurate in the setting of ARC, thus a measured creatinine clearance using serum and urine creatinine measurements are preferred. We describe the development of an 8‐h urine collection and ARC dosing program at a large academic medical center initiated by critical care and infectious disease pharmacists. Using a Plan–Do–Study–Act approach, we implemented and updated the 8‐h collection program with the guidance of our clinical laboratories. Eight‐hour urine collections are useful for patients with suspected ARC and for other scenarios where accurate dose adjustments are needed to minimize toxicity in the absence of therapeutic drug monitoring.

Background: Monitoring of vancomycin using the area under the curve (AUC) to minimum inhibitory concentration (MIC) ratio is now preferred for serious methicillin-resistant Staphylococcus aureus infections. Vancomycin AUC/MIC monitoring is being investigated but is not yet well elucidated with other bacterial pathogens. Methods: A retrospective cross-sectional study was conducted assessing patients with streptococcal bacteremia treated with vancomycin definitive therapy. AUC was calculated using a Bayesian approach, and classification and regression tree analysis was used to identify a vancomycin AUC threshold predictive of clinical failure. Results: Eleven patients had a vancomycin AUC < 329 of which 8 (73%) experienced clinical failure, while 35 patients had a vancomycin AUC ≥ 329 of which 12 (34%) experienced clinical failure ( P = .04). Hospital length of stay was longer in the AUC ≥ 329 group (15 vs 8 days, P = .05), whereas time to bacteremia clearance (29 [22-45] vs 25 [20-29] hours, P = .15) and toxicity incidence (13% vs 4%, P = 1) were similar between groups. Conclusions: This study identified a VAN AUC threshold of <329 to be predictive of clinical failure in patients with streptococcal bacteremia which should be interpreted as hypothesis-generating. Studies evaluating VAN AUC-based monitoring for streptococcal bloodstream infections along with other infection types are needed before implementation into clinical practice can be recommended.