Pneumonia due to Pseudomonas aeruginosa: the levofloxacin clinical trials experience

Respiratory infections caused by Pseudomonas aeruginosa present significant treatment challenges, including that of overcoming intrinsic and adaptive resistance by these organisms. The fluoroquinolones may provide an effective option for treating these infections. In this analysis, we report on the efficacy of levofloxacin in the treatment of community-acquired pneumonia (CAP) and nosocomial pneumonia caused by P. aeruginosa using information from nine clinical studies supported by Johnson & Johnson Pharmaceutical Research and Development (Raritan, NJ) or Ortho-McNeil Pharmaceutical (Raritan, NJ). From these studies, a total of 36 patients were identified with pneumonia caused by P. aeruginosa and treated with levofloxacin (750 mg or 500 mg). For patients diagnosed with nosocomial pneumonia, levofloxacin treatment achieved a 64.7% (11/17) clinical success rate, compared with 41.2% (7/17) with comparator treatment (imipenem/cilastatin followed by ciprofloxacin) in the microbiologically evaluable population. Eradication rates were 58.8% with levofloxacin treatment vs. 29.4% with comparator (95% CI, -64.2 to 5.4). For levofloxacin-treated CAP patients with P. aeruginosa infections (n = 19), clinical success and microbiological eradication rates in the microbiologically evaluable population were 89.5% and 78.9%, respectively. Several limitations of this analysis exist including that this was a retrospective evaluation that pooled data from multiple studies with varying protocols, the number of patients included was limited, and the nosocomial pneumonia patients used adjunctive therapy with an antipseudomonal beta-lactam in most cases. Nonetheless, these findings suggest that levofloxacin may play a role in the treatment of these difficult respiratory infections.