International journal of antimicrobial agents
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Int. J. Antimicrob. Agents · Jun 2011
ReviewClinical implications of β-lactam-aminoglycoside synergism: systematic review of randomised trials.
β-Lactam-aminoglycoside combinations are commonly used despite lack of evidence of a clinical benefit. In this study, all randomised controlled trials (RCTs) assessing directly the clinical implications of synergism by comparing a β-lactam with the same β-lactam in combination with an aminoglycoside as empirical or definitive therapy for any type of infection and clinical scenario were compiled. A systematic search was undertaken to identify all trials regardless of language, date or publication status. ⋯ Combination therapy resulted in a significantly higher incidence of adverse events, mainly nephrotoxicity. Overall, no clinical benefit was found for the use of a β-lactam with an aminoglycoside compared with a β-lactam alone. Treatment with β-lactams as monotherapy entailed more antibiotic regimen modifications in open trials.
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Int. J. Antimicrob. Agents · Jun 2011
Suppression of ciprofloxacin-induced resistant Pseudomonas aeruginosa in a dynamic kill curve system.
Current dosing approaches for treating microbial infections ignore resistant subpopulations. A clinical isolate of Pseudomonas aeruginosa was cultured in a dynamic in vitro kill curve system designed to simulate the half-lives of drugs in order to evaluate the drug-microbial response relationship. The first dose of ciprofloxacin (CIP) uses a concentration equivalent to the unbound fraction of a 200mg clinical dose. ⋯ The CIP MIC increased substantially from 0.13 μg/mL pre dose to 4 μg/mL at 12h after a CIP dose. In addition, aztreonam induced a similar resistance pattern as CIP, indicating that induction of resistance was not limited to fluoroquinolones. In conclusion, the in vitro dynamic kill curve system revealed that aminoglycosides, more than other classes of antibiotics, were effective against the CIP-induced resistant subpopulations.
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Int. J. Antimicrob. Agents · Jun 2011
Pharmacokinetics of a loading dose of amikacin in septic patients undergoing continuous renal replacement therapy.
Data on the optimal amikacin regimen during continuous renal replacement therapy (CRRT) are scarce and the proposed loading dose of 10mg/kg may result in inadequate drug levels. The aim of this study was to describe the pharmacokinetics of a 25 mg/kg first dose of amikacin in septic shock patients treated with CRRT. Serum samples were collected before (t=0 h) and at 1 (peak), 1.5, 4.5, 8 and 24 h after a 30-min amikacin infusion in 13 consecutive patients treated with a combination of amikacin and β-lactam. ⋯ In septic shock patients treated with CRRT, a first dose of ≥ 25 mg/kg amikacin is therefore required to reach therapeutic peak concentrations. However, as drug clearance is reduced, amikacin concentrations remained above the threshold of renal toxicity at 24h. The therapeutic benefit of high-dose aminoglycoside therapy should be balanced with its potential renal effects in septic patients receiving CRRT.