Improved Pneumonia Therapy.
The new-generation quinolones have already become "major players" for treating pneumonia. Other new drugs, notably the ketolides and cefditoren, a new cephalosporin, will soon be available, Dr. Ronald F. Grossman said at the annual American Lung Association/American Thoracic Society International Conference.
The new quinolones include 1evofloxacin, which is considered a secondgeneration drug; gatifloxacin, a third-generation agent with improved activity against gram-positive and atypical pneumonia pathogens; and moxifloxacin and gemifloxacin, fourth-generation quinolones that have even better gram-positive activity and "reasonable" activity against gram-negative bacteria, anaerobes, and atypical pathogens, said Dr. Grossman, chief of the department of pulmonary medicine and critical care at Mount Sinai Hospital in Toronto. Among the isolates that are resistant to penicillin, 48% are also resistant to erythromycin.
Of the new quinolones, moxifloxacin is notable because a single dose can maintain a high level of bactericidal activity for a relatively long time. And at standard dosages it remains at an inhibitory concentration for the longest period of time.
In addition, peak serum concentration levels of moxifloxacin far exceed the minimum drug concentration needed to inhibit 90% of most respiratory pathogens. The new quinolones are such potent and quick killers that antibiotic resistance does not seem to be much of a problem, so far, Dr. Grossman said at the conference, held in conjunction with the Canadian Lung Association's annual meeting.