ABSTRACT
Moxifloxacin is a respiratory quinolone that is expected to be useful for treating community-acquired bacterial pneumonia, but few clinical studies and not a detailed evaluation of its pharmacokinetics have been conducted in Japan in patients with pneumonia. We assessed the efficacy and safety of moxifloxacin in 18 patients with community-acquired bacterial pneumonia using pharmacokinetic-pharmacodynamic analysis. There was significant improvement in body temperature, white blood cell count, C-reactive protein, and chest X-ray score on day 3 of moxifloxacin treatment, which persisted until the completion of treatment (all p < 0.05). Nine strains, including Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae, and Enterobacter cloacae, were isolated from sputum cultures of nine patients. The isolated strains were eradicated by moxifloxacin. The mean area under the concentration-time curve from 0 to 24 hours [AUC(0-24 h) (AUC(0-24 h,ss))], maximum plasma concentration (C(max)), and trough plasma level (C(trough)) of moxifloxacin at steady state was 52.0 µg h/ml, 4.5, and 0.9 µg/ml, respectively. Mean AUC(0-24 h,ss)/mimimum inhibitory concentration (MIC), and C(max)/MIC ratios for patients in whom MICs of moxifloxacin were determined for pathogenic bacteria were 723 and 62, respectively. The median AUC(0-24 h,ss)/MIC and C(max)/MIC ratios (based on Monte Carlo simulation employing MICs for 257 strains of S. pneumoniae collected during a respiratory infection survey by the Japanese Society of Chemotherapy in 2007) were 209.56 and 17.88, respectively. Thus, when the target for the AUC/MIC ratio was set at ≥30 and that for the C(max)/MIC ratio at ≥5, the achievement rate for these two parameters was 97.36% and 96.71%, respectively. Two patients (11%) experienced three adverse effects [one nausea, another increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], but the events were not serious. Based on these results, moxifloxacin (400 mg once daily) was considered useful for treating community-acquired bacterial pneumonia and is expected to show excellent efficacy and safety as well as suppressing the emergence of resistance.
Subject(s)
Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Aza Compounds/adverse effects , Aza Compounds/therapeutic use , Community-Acquired Infections/drug therapy , Pneumonia, Bacterial/drug therapy , Quinolines/adverse effects , Quinolines/therapeutic use , Adult , Aged , Analysis of Variance , Anti-Bacterial Agents/pharmacokinetics , Area Under Curve , Aza Compounds/pharmacokinetics , Bacteria/drug effects , Cohort Studies , Community-Acquired Infections/metabolism , Community-Acquired Infections/microbiology , Computer Simulation , Female , Fluoroquinolones , Humans , Japan , Male , Microbial Sensitivity Tests , Middle Aged , Monte Carlo Method , Moxifloxacin , Pneumonia, Bacterial/metabolism , Pneumonia, Bacterial/microbiology , Quinolines/pharmacokinetics , Sputum/microbiology , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/isolation & purification , Treatment OutcomeABSTRACT
The efficacy and safety of gatifloxacin (GFLX) was evaluated for elderly patients with respiratory infections. Each patient received one-half (100 mg b.i.d.) or one-quarter (100 mg q.d.) of the conventional dosage of 200 mg b.i.d., after a tentative clinical dosage for GFLX was estimated based on the patient's age and body weight. The subjects were 34 patients aged 65 years or older with mild to moderate acute bronchitis, pneumonia, or chronic respiratory tract infections. The serum concentration of GFLX was measured for each patient, and population and pharmacokinetic (PPK) analysis was performed, using the Bayesian method, to calculate the AUC and maximum drug concentration (Cmax). The overall efficacy rate of GFLX for 33 patients was 87.9% (29/33 patients). GFLX was effective for 75.0% (6/8 patients) in the 100-mg dosage group and 92.0% (23/25 patients) in the 200-mg dosage group. The clinical efficacy was 90.0% (9/10 patients) for acute bronchitis, 86.7% (13/15 patients) for pneumonia, and 87.5% (7/8 patients) for chronic respiratory tract infections. The bacterial eradication rate was 85.7% (12/14 patients). No adverse events or laboratory abnormalities were observed. The AUC values were 11.2-37.5 microg.h/ml and 12.7-111 microg.h/ml for the 100-mg and 200-mg dosage groups, respectively, and the Cmax values were 1.28-3.02 microg/ml and 0.72-6.35 microg/ml, respectively, for the two groups. These results suggest that the dosage of GFLX examined in this study is clinically useful in elderly patients aged 65 or older with acute bronchitis, pneumonia, or chronic respiratory tract infections. The results of PPK analysis with the dosage management also support the efficacy of GFLX.
