Objective: To determine the factors affecting the antimicrobial effect of VCM on MRSA.
Study Design: Case series study.
Methods: This study was conducted on pneumonia patients admitted to a university-affiliated hospital between January 2000 and December 2008 and had MRSA in their sputum culture.  From seven days prior to the starting VCM administration through the end of the administration, detailed information such as underlying diseases, VCM serum concentration and quantity of MRSA were recorded.  Logistic regression analysis was carried out on current diseases, trough concentration, surgery experience, and the detection of Gram-negative bacteria to verify the antimicrobial effect of VCM.
Results: The number of subjects investigated this study was 55 subjects.  Multiple logistic regression analysis did not yield any significant factors when carried out using the factors affecting the antimicrobial effect of VCM on MRSA as independent variables.
Conclusions: Multivariable analysis yielded no factors as being significant in affecting the antimicrobial effect of VCM, but did indicate in that patients aged 70 and older, the antimicrobial effect of VCM was poor for MRSA.  This suggests that when pharmacists intervene in antimicrobial treatment for improved effects, it is important to consider not only the serum concentration of VCM, but also the background of the patient.