Use of microdialysis for the assessment of fluoroquinolone pharmacokinetics in the clinical practice.

Antibacterial drugs, including fluoroquinolones, can exert their therapeutic action only with adequate penetration at the infection site. Multiple factors, such as rate of protein binding, drug liposolubility and organ blood-flow all influence ability of antibiotics to penetrate target tissues. Microdialysis is an in vivo sampling technique that has been successfully applied to measure the distribution of fluoroquinolones in the interstitial fluid of different tissues both in animal studies and clinical setting. Tissue concentrations need to be interpreted within the context of the pathogenesis and causative agents implicated in infections. Integration of microdialysis -derived tissue pharmacokinetics with pharmacodynamic data offers crucial information for correlating exposure with antibacterial effect. This review explores these concepts and provides an overview of tissue concentrations of fluoroquinolones derived from microdialysis studies and explores the therapeutic implications of fluoroquinolone distribution at various target tissues.

Patterns of prescription antihypertensive drug utilization and adherence to treatment guidelines in the city of Novi Sad.

BACKGROUND/AIM: Hypertension is one of the leading causes of cardiovascular morbidity and mortality and more than a half of all health insurance expenditures for reimbursed medicines are allocated to antihypertensive drugs in Serbia. The aim of this study was to identify the antihypertensive drug utilization patterns among hypertensive outpatients in the city of Novi Sad, Serbia, determine the adherence to clinical guidelines and address the economic aspects of current prescribing practices. METHODS: This retrospective observational study was conducted in Novi Sad over a period of six months. The data on the number of packages, size their, and retail price of antihypertensives issued on prescription in outpatients with the diagnosis of essential arterial hypertension was collected from all state-owned pharmacies in Novi Sad. Drug consumption was analyzed using the Anatomical Therapeutic Chemical (ATC)/ defined daily dose (DDD) methodology. RESULTS: Total consumption of antihypertensives issued on prescription over a 6-month period in the city of Novi sad, Serbia was 283.48 DDD per 1,000 inhabitans per day (DID). Angiotensin converting enzyme inhibitors (ACEi) were most commonly prescribed drugs, and were used 3 times more often than calcium channel blockers and 5 times more than beta-blockers. The consumption of diuretics and angiotensin receptor antagonists was low within all the groups of outpatients. Both national and international guidelines state superiority and effectiveness of diuretics in treatment of hypertension in the elderly, but their consumption was unreasonable low despite the fact that over 70% of all antihypertensive drugs in the city of Novi Sad were dispensed in people aged > 60. The use of more expensive ACEi was observed despite the guidelines deeming all the drugs of this class equally effective in treatment of hypertension. CONCLUSION: Large differences in utilization of different groups of antihypertensive agents were noted in this study. Underutilization of valuable, efficacious, and cost-effective thiazide diuretics and overuse of expensive ACE inhibitors is unjustifiable. There is a potential for large savings with switching to low-price ACEi, modeling the practice of Scandinavian countries.

Quantitative assessment of the glyoxalase pathway in Leishmania infantum as a therapeutic target by modelling and computer simulation.

The glyoxalase pathway of Leishmania infantum was kinetically characterized as a trypanothione-dependent system. Using time course analysis based on parameter fitting with a genetic algorithm, kinetic parameters were estimated for both enzymes, with trypanothione derived substrates. A K(m) of 0.253 mm and a V of 0.21 micromol.min(-1).mg(-1)for glyoxalase I, and a K(m) of 0.098 mm and a V of 0.18 micromol.min(-1).mg(-1) for glyoxalase II, were obtained. Modelling and computer simulation were used for evaluating the relevance of the glyoxalase pathway as a potential therapeutic target by revealing the importance of critical parameters of this pathway in Leishmania infantum. A sensitivity analysis of the pathway was performed using experimentally validated kinetic models and experimentally determined metabolite concentrations and kinetic parameters. The measurement of metabolites in L. infantum involved the identification and quantification of methylglyoxal and intracellular thiols. Methylglyoxal formation in L. infantum is nonenzymatic. The sensitivity analysis revealed that the most critical parameters for controlling the intracellular concentration of methylglyoxal are its formation rate and the concentration of trypanothione. Glyoxalase I and II activities play only a minor role in maintaining a low intracellular methylglyoxal concentration. The importance of the glyoxalase pathway as a therapeutic target is very small, compared to the much greater effects caused by decreasing trypanothione concentration or increasing methylglyoxal concentration.