Class of 2011 Abstract / OBJECTIVES: The purpose of this study is to assess three published aminoglycoside dosing protocols (large-dose extended interval), to predict peak and trough concentrations of these protocols and to determine the percentage of patients with peak and trough concentrations within each protocol’s specified ranges. METHODS: This study is a retrospective analysis of clinical data. A database of 515 patients is used to analyze the three different protocols. The variables in this database encompass patients’ age, height, actual body weight (ABW), sex, k, Vd, and dose. From these data, patients' peak and trough concentrations were determined using the three large large, extended interval dosing protocols. RESULTS The results showed Nicolau protocol with the most potential of the three protocols. It had the highest percentages of patients with peak above 15 mg/L and a trough less than 0.5 mg/L. It also had the highest average peak of 19.1 mg/L with 69.9% of patients meeting the protocol’s specified peak range of 13 to 23 mg/L. CONCLUSION: The three examined protocols all showed a percentage of patients within the desired range. Of the three, Nicolau protocol I showed promising results with highest average peak, lowest average trough and high percentage of patients with concentrations within desired ranges. Its percentages above 15 mg/L and less than 0.5 mg/L are greater than protocols II and III. Nicolau dosing protocol may be best in achieving high peak and low trough concentrations.

Class of 2005 Abstract / Objectives: First, to evaluate five recent gentamicin dosing protocols that are specific for neonates and determine how frequently each protocol yields desirable peak and trough concentrations. Second, to make our evaluation more robust, we included AUC as one of the pharmacokinetic parameters and compared it to traditional parameters. Finally, to evaluate a fixed dosing protocol (3 mg/kg Q24-hours) that is currently being used at one Arizona hospital (UMC). Methods: This retrospective evaluation involved datasets from three independent sources. Dataset 1 was from a previously published study, while datasets 2 and 3 were derived for this study. Datasets 1 and 2 were pooled to evaluate the five dosing protocols, while dataset 3 was used to evaluate the fixed dosing protocol used at UMC. For all subjects, demographic and laboratory data was obtained from hospital databases or charts. The data collected was used to construct pharmacokinetic values, which in turn were used in simulations with the five protocols. Dataset 3 was evaluated as a whole for frequency of desired peaks and troughs, then for subsets based on weight, gestational age, and Apgar scores. Results: Of the five evaluated, the Avent protocol yielded the fewest potentially toxic troughs. The Murphy-Carter protocol stood out in that it was the easiest to use, most universally applicable, and it yielded only slightly fewer desired troughs then the Avent protocol. AUC values proved to be a novel and exceptionally useful tool in evaluating the dosing protocols. The fixed dosing protocol used at UMC was shown to consistently produce favorable trough concentrations as a whole as well as in our subset analyses. Implications: The multitude of dosing protocols that have been offered can create confusion among health care professionals and lead to discrepancies in dosing. The primary goal of any of these protocols is to minimize the risk of toxicity while avoiding subtherapeutic doses. A dosing protocol that can consistently meet these criterion, yet offer simplicity and wide applicability, then we can come that much closer to a universal standard.