Antibacterial activity against 67 Pseudomonas aeruginosa isolates from blood culture from 2000 to 2004 were studied by measuring the minimum inhibitory concentration (MIC) and compared to previous data.Optimized carbapenem dosing was designed using Monte Carlo simulation.
The MIC₉₀ of meropenem (MEPM), biapenem (BIPM), imipenem/cilastatin (IPM/CS) and panipenem/betamipron (PAPM/BP) was 16μg/mL, 16μg/mL, 32μg/mL, and 64μg/mL.
The MIC₉₀ of ciprofloxacin (CPFX) was 2μg/mL, the lowest MIC in antibiotics tested.The number of isolates producing class B β-lactamase was 1 (1.5%) and multidng-resistant or ganisms was 3 (4.5%).
Treatment with MEPM 0.5g×3/day conferred the highest probability (59.3%) of target attainment for target pharmacodynamic exposures (time above MIC was 50%). In conclusion, MEPM (0.5g×3/day) may be an effective regimen for empiric therapy against bacteremia with P.aeruginosa.

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From November, 2004 to March 2005, we found that gatifloxacin (GFLX) doses of 100mg b.i.d.(200mg/day) for the treatment of secondary infections in senior citizens (age≥65years) with chronic respiratory illness were as safe and effective as doses of 200 mg b.i.d.(400mg/day) in non senior citizens.
A controlled study was conducted to evaluate the efficacy of GFLX doses of 100mg b.i.d.in senior patients with chronic respiratory tract infections using levofloxacin (LVFX), a new quinolone antimicrobial drug, as the control drug.
We randomly distributed GFLX doses of 100mg b.i.d.or LFLX doses of 200mg b.i.d.to 72 patients (age≥65) with chronic respiratory tract infections between December 2005 and April 2007.Medications were administered to patients for 7 days.
We evaluated 60 patients (GFLX group: 33, LVFX group: 27) for the efficacy of medications, 70 patients (GFLX group: 36, LVFX group: 34) for side effects, and 65 (GFLX group: 35, LVFX group: 30) for abnormal laboratory results from a total of 72 patients.Clinical efficacy was 78.8%(26/33) in the GFLX group and 70.4%(19/27) in the LVFX group.Side effects were not observed in either group, and abnormal laboratory results were observed in 4 patients in the GFLX group. These abnormal laboratory results were generally mild in nature.
Our results suggest that GFLX doses of 100mg b.i.d.are as effective as or more effective than LVFX doses of 200 mg b.i.d.for the treatment of secondary infections resulting from chronic respiratory diseases in senior citizens.

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[Objective] This study was conducted in patients of secondary infection with chronic respiratory disease in order to compare 5 day short-course therapies employing gatifloxacin (GFLX) and levofloxacin (LVFX).In addition to the shortening of treatment periods, we also investigated the economic efficiency of this medical treatment.
[Materials and methods] A total of 74 patients with secondary infection in chronic respiratory disease were enrolled and treated with the study drugs.The study was conducted between September, 2006 and April, 2007 at Keio University Hospital and its affiliated hospitals and clinics.This was a randomized study in which patients were randomly assigned to one of the following two treatment groups: GFLX group (200 mg twice daily for patients aged≥65 years and 400 mg twice daily in patients aged<65 years), LVFX group (400 mg twice daily).The duration of antibiotic therapy was 5 days.
[Results] 61 patients (GFLX group: 32, LVFX group: 29) were evaluated for the efficacy of the medications, 74 patients (GFLX group: 37, LVFX group: 37) were evaluated for side effects, and 63 patients (GFLX group: 30, LVFX group: 33) were evaluated for abnormal laboratory results from a total of 74 patients.Clinical efficacy was 90.6%(29/32) in the GFLX group and 89.7%(26/29) in the LVFX group.Side effects were observed in 2 cases in the GFLX group, and 2 abnormal laboratory results were observed (1 in the GFLX group and 1 in the LVFX group).These cases were all mild in nature.
[Conclusion] Conventional management recommends 7-14 days of antibiotic therapy for secondary infection in patients with chronic respiratory disease.However, the optimum duration of treatment is less clear. This study suggests that for secondary infection in chronic respiratory disease, 5 day short-course therapy employing antibiotics therapy can be clinically successful.In terms of the economic efficiency of this medical treatment, GFLX is superior to LVFX due to the lower cost of this drug.These results show that therapy involving a 5 day short-course using GFLX is of greater benefit than therapy involving the use of LVFX.

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The use of antibacterial agents must have had a broad antibacterial spectrum and a strong antibacterial effect, and the medication plan of an antibacterial agent also considers pharmacokinetics in the treatment of bacterial infection. It is important to determine a medication interval based on “time above MIC” from a PK/PD in β-lactam antibacterial agents.
Ceftriaxone (CTRX), an injectable cephem antibacterial agent, has a broad antibacterial spectrum and strong antibacterial effect, and showed sufficient antibacterial effect in once-daily treatment and that the half-life in blood is very long. The Japanese Society of Chemotherapy strongly desires the approval for a once-daily dosing regimen of CTRX.
A survey on once-daily treatment with CTRX in pediatric bacterial infections yielded the following results.
Some 51% of respondents (28/55 doctors) had used CTRX in once-daily treatment. The distribution of dosage and term were 50-59 mg/kg for 5 days in inpatients and 20-59 mg/kg for 3 days in outpatients.
Advantages included outpatient use, administration without hospitalization equipment, maintenance of patient and family QOL and cutting of medical expenses after approval of once-daily CTRX treatment. Disadvantages included difficulty of the correspondence to the patients' emergency and the correspondence to adverse reactions of CTRX such as a drug allergy. The intentions to suppose that respondents want to use once-daily CTRX treatment were 80% for outpatients and 51% for inpatients respectively.
We consider that sufficient information about advantages and disadvantages of once-daily CTRX treatment should be offered to physicians for an appropriate use of this regimen.

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We determined the antibacterial activities of 19 antibiotics, including 5 carbapenems, against 124 strains isolated from the inpatients and outpatients with complicated urinary tract infections (c-UTIs) who were treated at Urology Clinic, Kagoshima University Medical Center between January 2004 and December 2005. The MICs were determined using the agar dilution method. Nine strains of Staphylococcus aureus, 13 strains of Enterococcus faecalis, 41 strains of Escherichia coli, 17 strains of Klebsiella spp., and 44 strains of Pseudomonas aeruginosa were examined.Vancomycin and teicoplanin were strongly active against the clinical isolates of Gram-positive bacteria, additionally, arbekacin was active against S. aureus, and ampicillin was active against E. faecalis.Imipenem and panipenem showed good activity against E. faecalis, but methicillin-resistant S. aureus were resistant to all the carbapenems. As for the clinical isolates of Gram-negative bacteria, carbapenems were active against almost all strains of Enterobacteriaceae, however fluoroquinolone (FQN)-resistant E. coli have been increasing since 2000. The percentage of FQN-resistant E. coli was about 25% in this study. Against the clinical isolates of P. aeruginosa, the MIC₉₀ of the carbapenems were 16-32mg/L and the resistance rate has been increasing. Six strains of multi-drug resistant P. aeruginosa were isolated. The resistance rates of urinary isolates to antimicrobials has been increasing, however, carbapenems retain their outstanding position as the antibacterial drugs of empiric choice for severe c-UTI patients, if they are used appropriately.

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