The efficacy of
arbekacin in patients with MRSA
infections is influenced by the peak concentration (Cpeak)/MIC ratio (≧8). A daily
arbekacin dose of 4-6 mg/kg is primarily used for the treatment of MRSA
infection. However, clinical pharmacokinetic studies of
arbekacin that evaluate changes in patients with different
infectious diseases have been limited. This study was to evaluate the pharmacokinetics of
arbekacin in different
infectious diseases and to evaluate its dosing regimens. This work describes a single-centre, retrospective study. The pharmacokinetic parameters of
arbekacin were calculated from individual serum-concentration data using WinNonlin ver. 6.3. A total of 331 serum samples were obtained from 170 patients. Our
drug concentration-time data were well described by a two-compartment open model. The final model showed that drug clearance was related to
creatinine clearance and that the total distribution volume (Vd) was related to actual
body weight and the presence of
bacteremia. The individual Vd in
bacteremia patients was significantly higher than those of other patients (
bacteremia: 29.7 ± 0.5 L,
pneumonia: 20.8 ± 0.4 L, other
infections: 21.4 ± 0.4 L; p < 0.05). Additionally, Monte Carlo simulation showed that target (Cpeak/MIC ≧ 8) attainment was only 10.1%, even at a dose of 6 mg/kg, especially for MRSA
bacteremia patients with an
arbekacin MIC = 2 μg/mL. In conclusion, our study revealed that the Vd may be higher in
bacteremia patients than in patients with other
infectious diseases. Therefore, an increase in the daily dose of
arbekacin should be considered for
bacteremia patients.