Pediatric Antibiotic Stewardship: Optimization of Vancomycin Therapy Based on Individual Pharmacokinetics.

BACKGROUND: Vancomycin has been a first-line treatment for Gram-positive infections for decades. However, strategies for therapeutic drug monitoring (TDM) and dose-optimization in pediatrics remain controversial. In this study, we analyzed the impact of specific antibiotic stewardship interventions on efficacy and safety of vancomycin therapy. METHODS: From September 2014 to May 2017, we conducted a prospective study to compare a control and a TDM intervention group in our tertiary care center. As part of an antibiotic stewardship program, we implemented internal guidelines on correct vancomycin dosing, TDM timing, as well as targeted trough level range and installed a pharmacokinetic (PK) consultation service to adapt vancomycin dosing to individually calculated PK parameters. As primary clinical outcomes, the percentage of patients with sustained therapeutic vancomycin trough levels and treatment days with therapeutic vancomycin trough levels, that is, 10-15 mg/L were analyzed. Secondary outcomes included nephrotoxicity, readmission rate and mortality. Median daily dose required to achieve therapeutic trough levels was examined. RESULTS: Clinical outcomes for 90 control patients were compared with outcomes for 19 patients guided by a PK consultation service. Percentage of patients with sustained therapeutic vancomycin trough levels increased from 17.8% to 94.7% (P < 0.001) and percentage of treatment days with therapeutic vancomycin trough levels increased from 18.4% (117/637) to 665% (155/233, P < 0.001). Readmission rate decreased from 24.4% to 5.3% (P = 0.07). No differences in nephrotoxicity or mortality rate were observed between groups. A median daily dose of 72 mg/kg/d was required to achieve therapeutic trough levels. CONCLUSIONS: Our data demonstrate that implementation of internal guidelines and a PK consultation service was associated with a profound improvement of vancomycin therapy and, therefore, patient safety.

Pediatric antibiotic stewardship: successful interventions to reduce broad-spectrum antibiotic use on general pediatric wards.

PURPOSE: Antibiotic stewardship programs (ASP) optimize antibiotic usage and combat antibiotic resistance of bacteria. The objective of this study was to assess the impact of specific ASP interventions on antibiotic consumption in general pediatric wards. METHODS: We conducted a prospective study to compare a pre-intervention (Sept.-Dec. 2014) and post-intervention (Sept.-Dec. 2015) period. An ASP bundle was established including (1) infectious diseases (ID) ward rounds (prospective-audit-with-feedback), (2) ID consultation service, (3) internal guidelines on empiric antibiotic therapy. Medical records on four general pediatric wards were reviewed daily to analyze: (1) antibiotic consumption, (2) antibiotic dosage ranges according to local guidelines, and (3) guideline adherence for community-acquired pneumonia (CAP). RESULTS: Antibiotic prescribing for 273 patients (pre-intervention) was compared to 263 patients (post-intervention). Antibiotic prescription rate did not change (30.6 vs. 30.5%). However, overall days-of-therapy and length-of-therapy decreased by 10.5 and 7.7%, respectively. Use of cephalosporins and fluoroquinolones decreased by 35.5 and 59.9%, whereas the use of penicillins increased by 15.0%. An increase in dosage accuracy was noted (78.8 vs. 97.6%) and guideline adherence for CAP improved from 39.5 to 93.5%. Between the two study periods, no adverse effects regarding length of hospital stay and in-hospital mortality were observed. CONCLUSIONS: Our data demonstrate that implementation of an ASP was associated with a profound improvement of rational antibiotic use and, therefore, patient safety. Considering the relatively short observation period, the long-term effects of our ASP bundle need to be further investigated.

Absorption of ipratropium and l-carnitine into the pulmonary circulation of the ex-vivo rat lung is driven by passive processes rather than active uptake by OCT/OCTN transporters.

The organic cation transporters OCT and OCTN have been reported to play a significant role in the cellular uptake of substrates within in vitro lung cells. However, no studies to date have investigated the effect of these transporters upon transepithelial absorption of substrates into the pulmonary circulation. We investigated the contribution of OCT and OCTN transporters to total pulmonary absorption of l-carnitine and the anti-muscarinic drug, ipratropium, across an intact isolated perfused rat lung (IPRL). The results obtained from the IPRL were contrasted with active transport in vitro using three human pulmonary cell lines and primary rat alveolar epithelial cells. Ex-vivo studies showed that OCT/OCTN transporters do not play a role in the overall pulmonary absorption of l-carnitine or ipratropium, as evidenced by the effect of chemical inhibition of these transporters upon pulmonary absorption. In contrast, in vitro studies showed that OCT/OCTN transporters play a significant role in cellular accumulation of substrates with preferential uptake of ipratropium by OCTs, and of l-carnitine uptake by OCTNs. The results show that in vitro uptake studies cannot be predictive of airway to blood absorption in vivo. Nevertheless, localised submucosal pulmonary concentrations of inhaled drugs and their pulmonary pharmacodynamic profiles may be influenced by OCT/OCTN transport activity.

Spatial expression and functionality of drug transporters in the intact lung: objectives for further research.

This commentary provides a background appraising evidence in the intact lung on the spatial expression of drug transporters and, where available, evidence in the intact lung of the impact, or otherwise, that such transporters can have upon pulmonary drug absorption and disposition. Ultimately drug discovery and development scientists will wish to identify in a 'pulmonary' context the effect of disease upon transporter function, the potential for drug transporters to contribute to drug-drug interactions and to inter-individual variation in drug handling and response. The rate and extent of lung epithelial permeation of drugs involve an interplay between the dose and the deposition site of drug within the lung and physiological variables operational at the epithelial-luminal interface. Amongst the latter variables is the potential impact of active transporter processes which may well display regio-selective characteristics along the epithelial tract. In pulmonary tissues the spatial pattern of drug transporter expression is generally poorly defined and the functional significance of transporters within the intact lung is explored in only a limited manner. Active transporters in the lung epithelium may affect airway residence times of drug, modulate access of drug to intracellular targets and to submucosal lung tissue, and potentially influence airway to systemic drug absorption profiles. Transporters in the lung tissue may also have the capacity to mediate uptake of drug from the systemic circulation resulting in drug accumulation in the lung. Transporters have physiological roles and new drug candidates while not necessarily serving as transport substrates may modulate transporter activity and hence physiology. The commentary highlights a series of recommendations for further work in pulmonary drug transporter research.