International journal of antimicrobial agents
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Int. J. Antimicrob. Agents · Nov 2014
Plasma and cerebrospinal fluid concentrations of linezolid in neurosurgical critically ill patients with proven or suspected central nervous system infections.
Linezolid is a valuable treatment option for central nervous system (CNS) infections caused by multidrug-resistant Gram-positive micro-organisms. Data regarding its penetration into the CNS have shown wide variability. The aim of this study was to describe the population pharmacokinetics of linezolid in plasma and cerebrospinal fluid (CSF) in critically ill patients with external CSF drainage and proven or suspected CNS infections. ⋯ No covariate relationships could be supported on any of the parameters. Linezolid demonstrated good penetration into the CNS but high interindividual PK variability. Administration of higher than standard doses of linezolid and therapeutic drug monitoring should therefore be considered as options to optimise linezolid dosing in critically ill patients with CNS infections.
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Int. J. Antimicrob. Agents · Nov 2014
Evaluation of teicoplanin concentrations and safety analysis in neonates.
The aims of this study were (i) to evaluate the relationship between teicoplanin (TEIC) dosage and subsequent trough concentration, (ii) to investigate factors that affect TEIC serum concentration fluctuations and (iii) to examine the association between serum concentration of TEIC and adverse reactions in neonates. A total of 37 eligible neonates (<28 days of age) treated with TEIC from 2008-2012 were included in this study. The median trough concentration in the loading dose regimen of >12-16 mg/kg on Day 1, followed by >6-8 mg/kg every 24 h (q24 h) was 19.6 μg/mL on Day 3 or 4, and the median trough concentration in the maintenance dose regimen of >6-8 mg/kg q24 h was 18.5 μg/mL at steady-state. ⋯ The incidence of hepatic dysfunction, renal impairment and thrombocytopenia was 14.8%, 20.0% and 14.8%, respectively. There was no significant difference in the incidence of adverse reactions between the trough concentration <20 μg/mL and ≥20 μg/mL groups. These data suggest that the recommended TEIC dosage for neonates is appropriate to achieve and maintain a trough concentration range of 15-30 μg/mL, and it is possible to set the target trough concentration at ≥20 μg/mL for deep-seated infections such as endocarditis, bone and joint infections, and osteomyelitis.
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Int. J. Antimicrob. Agents · Oct 2014
Randomized Controlled Trial Comparative StudyPharmacokinetics of imipenem in critically ill patients during empirical treatment of nosocomial pneumonia: a comparison of 0.5-h and 3-h infusions.
In critically ill patients, pathophysiological changes alter the pharmacokinetics of antibiotics. Imipenem exhibits primarily time-dependent killing. Its administration by prolonged infusion may increase the time for which its plasma concentration exceeds the minimum inhibitory concentrations (MICs) of suspected pathogens. ⋯ The study included 22 patients. Whilst no significant differences were found between both groups for %fT>MIC, %fT>4×MIC was 87.4±12.19%, 68.6±15.08%, 47.31±6.64% and 27.81±9.52% of the 8-h interval in the short infusion group for MICs of 0.5, 1, 2 and 4mg/L, respectively, and 85.15±17.57%, 53.14±27.27%, 13.55±24.47% and 0±0% of the 6-h interval for the extended infusion group. In conclusion, administration of 0.5g of imipenem by a 3-h infusion every 6h does not provide sufficient drug concentrations to treat infections caused by pathogens with a MIC of ≥2mg/L.
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Int. J. Antimicrob. Agents · Sep 2014
Analysis of thrombocytopenic effects and population pharmacokinetics of linezolid: a dosage strategy according to the trough concentration target and renal function in adult patients.
The pharmacokinetic/pharmacodynamic (PK/PD) index for the efficacy of linezolid is a 24-h area under the plasma drug concentration-time curve (AUC₂₄)/minimum inhibitory concentration (MIC) ratio of ≥100. The main adverse event associated with administration of linezolid is thrombocytopenia. Therefore, the aims of the present study were to define PD thresholds that would minimise linezolid-induced thrombocytopenia and to perform a population PK analysis to identify factors influencing the pharmacokinetics of linezolid. ⋯ Therefore, the target Cmin range was 3.6-8.2 μg/mL. The following formula to achieve a target Cmin in patients with different degrees of renal function was proposed based on these results: initial daily dose (mg/day)=CL × AUC₂₄=(0.0258 × CLCr + 2.03)×(18.2 × Cmin + 134.4). This recommended initial dosage and subsequent dosage adjustment for the target concentration range should avoid adverse events, thereby enabling effective linezolid-based therapies to be continued.
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Int. J. Antimicrob. Agents · Sep 2014
Multicenter Study Observational StudyClinical characteristics of patients with community-acquired complicated intra-abdominal infections: a prospective, multicentre, observational study.
In this prospective, observational, multicentre study using data from five countries (Columbia, The Philippines, Portugal, Taiwan and Thailand), the clinical impact of extended-spectrum β-lactamase (ESBL)-producing organisms on hospitalised patients with community-acquired complicated intra-abdominal infections (CA-cIAIs) was compared with that of non-ESBL-producing organisms during the period April 2010 to December 2011. Adult patients (aged ≥18 years) requiring surgery or percutaneous drainage were enrolled and were followed during the first hospitalisation course. An unadjusted statistical comparison of risk factors for ESBL-positive and ESBL-negative patients was performed. ⋯ The median LOS was 11.6 days for patients with infections due to ESBL-negative organisms and 17.6 days for patients with infections due to ESBL-positive organisms (P=0.011). Multivariate logistic regression analysis revealed that pre-existing co-morbidities, but not ESBL positivity, were adversely associated with clinical cure of CA-cIAIs. In contrast, duration of hospitalisation was longer for patients with CA-cIAI due to ESBL-positive organisms.