Last update:
21-May-2008

Community-acquired pneumonia (CAP) is the most severe respiratory infection caused by Streptococcus pneumoniae (S. pneumoniae). The empirical treatment of CAP includes the administration of a β-lactam or/and a macrolide for a period of 7 to 10 days. However, an accelerating growth of pneumococci strains resistant to a large number of antibiotics has been observed. About 40% of S. pneumoniae strains worldwide do not respond adequately to common antimicrobial treatment. This phenomenon has emphasised the need for using new, more effective drugs in the treatment of pneumococci infections, the most important of which are the latest quinolones. The ability of fluoroquinolones to inhibit bacterial protein synthesis by affecting two different enzymes (topoisomerase II and topoisomerase IV), combined with their favorable pharmacological properties, have established them among the most effective drugs used in the treatment of numerous infections caused by not only S. pneumoniae but also by other Gram positive and Gram negative bacteria. Retrospective epidemiological studies worldwide have shown that during the last fifteen years there has been an increase of up to seven times in the prescription rate of quinolones. About 50% of that increase involves respiratory infections, with patients of over 65 years the group for whom quinolones were most commonly prescribed. Although in Greece pneumococci strains resistant to fluoroquinolones have been observed, this phenomenon is already a problem for many countries, in some of which the percentage rate of resistant strains has doubled over a short period of time. For this reason it is important to determine the indications for fluoroquinolones administration for respiratory infections, in order to minimize the possibility of new, resistant strains of S. pneumoniae to evolve under the pressure of natural selection.

Key words: Community-acquired pneumonia, Fluoroquinolones, S. pneumoniae.