Lower Respiratory Tract Infections: Treatment Challenges and New Therapeutic Options

Lower respiratory tract infections (LRTis) include a number of different entities, ranging from acute bronchitis in a young, previously well person to ventilator-associated pneumonia in an older patient with comorbid illness . At one end of the spectrum, it is clear that antibiotics are unnecessary, while at the other end of the spectrum aggressive combination antimicrobial therapy is required and crude mortality rates of up to 70% have been reported. Two entities fall between these extremes: acute bacterial exacerbations of chronic bronchitis (ABECB), and community-acquired pneumonia (CAP) . Together they account for millions of health care dollars spent, much antibiotic use, and significant morbidity and mortality. During the past decade we have seen a disquieting increase in the incidence of resistance among respiratory pathogens. The pneumococcus that demonstrated a remarkably stable in vitro susceptibility pattern to beta-lactams in general, and to penicillin in particular, for over 40 years suddenly showed an increase in resistance not only to these drugs but to macrolides and, in some cases other agents as well. Resistance mediated by beta-lactamase production by Haemophilus iryluenzae and Moraxella catarrhalis has also