Abstract
In order to evaluate antibacterial activities of combination uses of isepamicin (ISP) and β-lactams in vitro, minimum inhibitory concentrations (MICs) these drugs were examined singly and in combination against clinically isolated Staphylococcus aureus.
The results are summarized as follows;
1. MICs of ISP+cefazolin (CEZ), ISP+cefotiam (CTM) and ISP+flomoxef (FMOX) were low and the activities against methicillin (DMPPC)-susceptible S. aureus (MSSA) were dependent on the concentration of ISP. Combined effects were observed when the concentrations of ISP were at sub-MIC levels (1/2-1/4 MIC concentrations).
2. MICs of ISP+CEZ, ISP+CTM, ISP+FMOX, ISP+imipenem and ISP+panipenem were low and the activities against DMPPC-resistant S. aureus(MRSA) were dependent on the concentration of ISP, and were similar to those against MSSA. Combined effects were observed when the concentrations of ISP were at sub-MIC levels of ISP. Lower MIC50 or MIC90, was observed at ISP concentrations of 4-16ug/ml.
3. The blood Cmax of ISP exceeded 20ug/ml at one-time administration of ISP 400 mg, and these results suggested that antibacterial activities of combination uses of ISP and β-lactams was clinically effective against MRSA infections.
