Role of therapeutic drug monitoring in pulmonary infections : use and potential for expanded use of dried blood spot samples

Respiratory tract infections are among the most common infections in men. We reviewed literature to document their pharmacological treatments, and the extent to which therapeutic drug monitoring (TDM) is needed during treatment. We subsequently examined potential use of dried blood spots as sample procedure for TDM. TDM was found to be an important component of clinical care for many (but not all) pulmonary infections. For gentamicin, linezolid, voriconazole and posaconazole dried blood spot methods and their use in TDM were already evident in literature. For glycopeptides, beta-lactam antibiotics and fluoroquinolones it was determined that development of a dried blood spot (DBS) method could be useful. This review identifies specific antibiotics for which development of DBS methods could support the optimization of treatment of pulmonary infections

Risk factors contributing to a low darunavir plasma concentration

Darunavir is an efficacious drug; however, pharmacokinetic variability has been reported. The objective of this study was to find predisposing factors for low darunavir plasma concentrations in patients starting the once- or twice-daily dosage. Darunavir plasma concentrations from January 2010 till December 2014 of human immunodeficiency virus-infected individuals treated in the outpatient clinic of the University Medical Center Groningen were retrospectively reviewed. The first darunavir plasma concentration of patients within 8weeks after initiation of darunavir therapy was selected. A dichotomous logistic regression analysis was conducted to select the set of variables best predicting a darunavir concentration below median population pharmacokinetic curve. In total 113 patients were included. The variables best predicting a darunavir concentration besides food intake included age together with estimated glomerular filtration rate (Hosmer-Lemeshow test P=0.945, Nagelkerke R-2=0.284). Systematic evaluation of therapeutic drug monitoring results may help to identify patients at risk for low drug exposure

Linezolid pharmacokinetics in MDR-TB : a systematic review, meta-analysis and Monte Carlo simulation

This work was supported by the Wellcome Trust (grant numbers 109129/Z/15/Z to JM and 105620/Z/14/Z to DS and MC).Objectives The oxazolidinone linezolid is an effective component of drug - resistant TB treatment, but use is limited by toxicity and the optimum dose is uncertain . Current strategies are not informed by clinical pharmacokinetic/pharmacodynamic (PK/PD) data, we aimed to aimed to address this gap. Methods We defined linezolid PK/PD targets for efficacy; free area under the time - concentration curve: minimum inhibitory concentration ratio (ƒAUC0-24:M IC) >119m g/L/hr and safety; free minimum concentration (Cmin) <1.38mg/L . We extracted individual - level linezolid PK data from existing studies on TB patients and performed meta - analysis; producing summary estimates of ƒAUC0-24 and ƒCmin for published doses . Combining these with a published MIC distribution, we performed Monte Carlo simulations of target attainment. Results The efficacy target was attained in all simulated individuals at 300mg q12h and 600mg q12h , but only 20.7% missed the safety target at 300mg q12h versus 98.5% at 600mg q12h . Although suggesting 300mg q12h should be used preferentially, these data were reliant on a single centre . Efficacy and safety targets were missed by 41.0% and 24.2% respectively at 300mg q24h , and 44.5% and 27.5% at 600mg q24h . However, the confounding effect of between study heterogeneity on target attainment for q24h regimens was considerable. Conclusions 300mg q12h linezolid dosing may retain the efficacy of the 600mg q12h licensed dosing with improved safety. Data to evaluate commonly used 300mg q24h and 600mg q24h doses is limited. Comprehensive, prospectively obtained PK/PD data for linezolid doses in drug - resistant TB treatment are required.Publisher PDFPeer reviewe

Clinical standards for the dosing and management of TB drugs

BACKGROUND: Optimal drug dosing is important to ensure adequate response to treatment, prevent development of drug resistance and reduce drug toxicity. The aim of these clinical standards is to provide guidance on 'best practice´ for dosing and management of TB drugs.METHODS: A panel of 57 global experts in the fields of microbiology, pharmacology and TB care were identified; 51 participated in a Delphi process. A 5-point Likert scale was used to score draft standards. The final document represents the broad consensus and was approved by all participants.RESULTS: Six clinical standards were defined: Standard 1, defining the most appropriate initial dose for TB treatment; Standard 2, identifying patients who may be at risk of sub-optimal drug exposure; Standard 3, identifying patients at risk of developing drug-related toxicity and how best to manage this risk; Standard 4, identifying patients who can benefit from therapeutic drug monitoring (TDM); Standard 5, highlighting education and counselling that should be provided to people initiating TB treatment; and Standard 6, providing essential education for healthcare professionals. In addition, consensus research priorities were identified.CONCLUSION: This is the first consensus-based Clinical Standards for the dosing and management of TB drugs to guide clinicians and programme managers in planning and implementation of locally appropriate measures for optimal person-centred treatment to improve patient care.CONTEXTE : Une posologie optimale est importante afin de garantir une réponse adéquate au traitement, de prévenir le développement de résistances aux médicaments et de réduire la toxicité liée aux médicaments. L’objectif de ces normes cliniques est de donner des indications de « bonne pratique » en matière de posologie et de gestion des agents antituberculeux. MÉTHODES : Un panel de 57 experts internationaux spécialisés en microbiologie, pharmacologie et soins antituberculeux a été identifié ; 51 ont participé à un processus Delphi. Une échelle de Likert à 5 points a été utilisée pour noter les premières ébauches des normes. Le document final est fondé sur un large consensus puisqu’il a été approuvé par tous les participants. RÉSULTATS : Six normes cliniques ont été définies : Norme 1, définir la dose initiale la mieux adaptée au traitement de la TB ; Norme 2, identifier les patients potentiellement à risque d’exposition sous-optimale aux médicaments ; Norme 3, identifier les patients à risque de développer une toxicité liée aux médicaments et déterminer comment diminuer au mieux ce risque ; Norme 4, identifier les patients pouvant bénéficier d’un suivi thérapeutique pharmacologique (TDM) ; Norme 5, définir les informations et conseils à fournir aux patients placés sous traitement antituberculeux et Norme 6, enseigner les fondamentaux aux professionnels de santé. Les priorités de recherche ont également été définies, sur la base d’un consensus. CONCLUSION : Il s’agit des premières normes cliniques, fondées sur un consensus, en matière de posologie et de gestion des antituberculeux. Elles ont pour objectif d’orienter les cliniciens et les responsables de programme en matière de planification et de mise en place de mesures locales adéquates pour un traitement optimal centré sur le patient, afin d’améliorer la prise en charge