Evaluation of arbekacin anti-MRSA agents for adult in Japan.

There are a limited number of reports that compare the clinical efficacy of anti-MRSA agents such as arbekacin (ABK), vancomycin (VCM), teicoplanin (TEIC) and linezolid (LZD). There is a tendency for these four agents to show variation in the inflammatory response parameters, in C-reactive protein (CRP) and in white blood cell count (WBC), depending on the administration period. There was no significant difference among the agents in analysis of variance (ANOVA) in the group of days 1-3 (p = 0.0536) but there was some significant difference in the group of days 4-7, as well as days 8-14 (p < 0.001, p < 0.01) in relative variation rate of CRP. Furthermore, we compared in more detail the groups of LZD, VCM and ABK, with a significant decrease of CRP, each of which showed more decrease in comparison with the group of TEIC in the period days 4-7 (p < 0.01). We took 1-hr serum level after days 3-4, with the ABK treatment as the peak concentration (C(peak)). Having made nonlinear logistic regression analysis of CRP and C(peak)/MIC, we concluded that the decrease rate estimable by early inflammatory effect could be decreased to some 40%, assuming that C(peak)/MIC shows the high value within 4 days after ABK treatment.

Clinical efficacy of arbekacin for Gram-negative bacteria.

In an analysis of methicillin-resistant Staphylococcus aureus (MRSA) infected patients treated with arbekacin (ABK) only, Gram-negative bacteria (GNB) that were inhibited by low minimal inhibitory concentrations (MICs) of amikacin (AMK) or gentamycin (GM) were eradicated by the end of the ABK treatment. On the other hand, GNB that were only inhibited by high MICs of AMK or GM persisted until the end of treatment with ABK only. Thus, ABK can be expected to be effective even in cases of mixed infection with GNB and MRSA.