gemifloxacin and Gram-Negative-Bacterial-Infections

Community-acquired lower respiratory tract infections (LRTIs) are more prevalent in the elderly than in children and younger adults and form a significant proportion of all consultations and hospital admissions in this older age group. Furthermore, in a world of increasing life expectancy the trend seems unlikely to be reversed. Antimicrobial treatment of community-acquired pneumonia (CAP) must cover Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, and in many circumstances should also cover the intracellular (atypical) pathogens. In contrast, acute exacerbations of chronic bronchitis (AECB) are mainly associated with H. influenzae and S. pneumoniae and not with atypical bacteria: in severe cases, other Gram-negative bacteria may be involved. Frequently in LRTIs, the aetiology of the infection cannot be identified from the laboratory specimens and treatment has to be empirical. In such situations it is important to not only to use an antibiotic that covers all likely organisms, but also one that has good activity against these organisms given the local resistance patterns. Gemifloxacin is a new quinolone antibiotic that targets pneumococcal DNA gyrase and topoisomerase IV and is highly active against S. pneumoniae including penicillin-, macrolide- and many ciprofloxacin-resistant strains, as well as H. influenzae and the atypical pathogens. In clinical trials in CAP and AECB, gemifloxacin has been shown to be as effective a range of comparators and demonstrated an adverse event profile that was in line with the comparator agents. In one long-term study in AECB significantly more patients receiving gemifloxacin than clarithromycin remained free of recurrence after 26 weeks. The improved potency, broad spectrum of activity and proven clinical and bacteriological efficacy and safety profile should make it a useful agent in the 21st century battle against community-acquired LRTIs.

Topics: Anti-Bacterial Agents; Bronchitis; Chlamydophila Infections; Community-Acquired Infections; Fluoroquinolones; Gemifloxacin; Gram-Negative Bacterial Infections; Haemophilus Infections; Humans; Legionnaires' Disease; Moraxellaceae Infections; Naphthyridines; Pneumococcal Infections; Pneumonia, Bacterial; Pneumonia, Mycoplasma; Staphylococcal Infections

An open-label, non-comparative study assessed the clinical and bacteriological efficacy of gemifloxacin (320 mg, once-daily for 7 days) in lower respiratory tract infections (LRTI). Patients with acute exacerbation of chronic bronchitis (AECB, n=261) or community-acquired pneumonia (CAP, n=216) were enrolled into the study. Clinical success rates at follow-up (days 21-28) in the intent-to-treat (ITT) population were high, 83.1% in AECB patients (95% CI: 77.9, 87.4) and 82.9% in CAP patients (95% CI: 77.0, 87.5). High bacteriological success rates were achieved (bacteriological ITT population), 91.2% (52/57) in AECB patients (95% CI: 80.0, 96.7) and 77.9% (60/77) in CAP patients (95% CI: 66.8, 86.3). Gemifloxacin was well tolerated with a low incidence of adverse events. Gemifloxacin treatment resulted in high clinical and bacteriological success rates and is a well-tolerated therapy for the treatment of LRTIs.

Topics: Adult; Aged; Anti-Infective Agents; Bronchitis; Chronic Disease; Community-Acquired Infections; Drug Administration Schedule; Female; Fluoroquinolones; Gemifloxacin; Gram-Negative Bacterial Infections; Haemophilus Infections; Humans; Klebsiella Infections; Male; Middle Aged; Naphthyridines; Pneumococcal Infections; Pneumonia, Bacterial; Staphylococcal Infections; Treatment Failure

The in vitro activity of gemifloxacin against over 4900 bacterial isolates was determined by microbroth dilution with interpretation in accordance with NCCLS guidelines. Susceptibility results were compared with those for ciprofloxacin, gatifloxacin, levofloxacin and moxifloxacin. Gemifloxacin and the other fluoroquinolones were not affected by either beta-lactamase production or penicillin-resistance in Streptococcus pneumoniae. The MIC90 values for gemifloxacin were: S. pneumoniae 0.063 mg/l; Haemophilus influenzae 0.016 mg/l; Moraxella catarrhalis 0.008 mg/l, methicillin-susceptible Staphylococcus aureus 0.063 mg/l; methicillin-susceptible Streptococcus pyogenes 0.031 mg/l; Enterobacteriaceae 0.031-0.16 mg/l; Pseudomonas aeruginosa 4 mg/l; Neisseria meningitidis 0.008 mg/l. The MIC90 for gemifloxacin was lower than those for the other quinolones tested against S. pneumoniae (ciprofloxacin 2-4 mg/l, gatifloxacin 0.5 mg/l, levofloxacin 1-2 mg/l, moxifloxacin 0.25 mg/l). This study confirms the enhanced potent activity of gemifloxacin against Gram-positive pathogens, its broad-spectrum, Gram-negative activity and indicates that gemifloxacin is likely to have an important role in treating patients with Gram-positive and/or Gram-negative infections.

Topics: Anti-Infective Agents; Bacteria; Canada; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; Fluoroquinolones; Gemifloxacin; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; In Vitro Techniques; Microbial Sensitivity Tests; Naphthyridines