Evaluation of clinical dosage of gatifloxacin for respiratory tract infections in elderly patients

Abstract number: 1733_1511

Yoneyama H., Niki Y., Matsushima T.

Objectives: We studied the efficacy and safety of gatifloxacin in elderly patients with respiratory tract infections, in addition of the pharmacokinetic analysis.

Methods: Thirty four patients, 65–93 years-old, with mild to moderate acute bronchitis (10 cases), pneumonia (16 cases) and acute exacerbation of chronic respiratory disease (8 cases) were administered 100 mg once or twice daily for 3 to 14 days. Gatifloxacin was dosed as below, on based of the body weight and age of patients.

Serum level of gatifloxacin (1 to 3 samples in each patient) was determined and the AUC and Cmax was calculated by using the Bayesian method with population pharmacokinetic parameters.

Results: Total efficacy rate was 84.8% (28/33) at day3 and 87.9% (29/33) at the end of treatment. For each dose, it was 75% (6/8) at 100 mg once daily and 92.0% (23/25) at 100 mg b.i.d. For each infection, it was 90.0% (9/10), 86.7% (13/15) and 87.5% (7/8) for acute bronchitis, pneumonia and acute exacerbation of chronic respiratory diseases, respectively. Fifteen pathogens such as S. pneumoniae, B. catarrhalis and H. influenzae were isolated from 13 patients. All strains except for MRSA and E. faecalis were eradicated after administration of gatifloxacin. Side effect and clinical abnormality was not observed.

The pharmacokinetic parameters were as follows: The AUCs of patients dosed 100 mg once daily and b.i.d. ranged 11.2 to 37.5 and 12.7 to 111 mg*h/L, respectively. AUC/MICs for 2 S. pneumoniae isolates were 39 and 67, and for all of H. influenzae and M. catarrhalis were >250. Cmax level of gatifloxacin ranged 0.72 to 3.36 mg/L, except for one patient with Cmax of 6.35 mg/L.

Body weight (kg)Age (yrs)
<=40100 mg × 1 (1)100 mg × 1 (2)100 mg × 1 (1)
41–60100 mg × 2 (6)100 mg × 2 (13)100 mg × 1 (4)
>=61100 mg × 2 (4)100 mg × 2 (3)100 mg × 2 (0)
( ): No. of cases.

Conclusion: It was suggetsted that gatifloxacin of 100 mg once or twice daily could achieve an adequate AUC and high clinical efficacy and tolerance in elderly patients with respiratory tract infections.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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