[Antibacterial activities of combination uses of isepamicin and beta-lactams in vitro against clinically isolated strains. Part 1. Activities against Staphylococcus aureus].
In order to evaluate antibacterial activities of combination uses of isepamicin (ISP) and beta-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 approximately 1/4 concentrations). 2. MICs of ISP + CEX, 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 approximately 16 micrograms/ml. 3. The blood Cmax of ISP exceeded 20 micrograms/ml at one-time administration of ISP 400 mg, and these results suggested that antibacterial activities of combination uses of ISP and beta-lactams was clinically effective against MRSA infections.
Deguchi
K
K
Section of Studies, Tokyo Clinical Research Center, Japan.
Koguchi
M
M
Suzuki
Y
Y
Tanaka
S
S
Fukayama
S
S
Ishihara
R
R
Oda
S
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001424:Bacterial Infections / Q000382:microbiology; D002437:Cefazolin / Q000494:pharmacology; D015310:Cefotiam / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D016106:Methicillin Resistance; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D005839:Gentamicins; D015310:Cefotiam; C016927:isepamicin; D002437:Cefazolin; C045693:flomoxef