Empirical treatment of nonsevere community-acquired pneumonia: still a difficult issue.

erythromycin resistance (<5%) in Europe are reported from Switzerland, Germany and the UK. In 1979, Spain had <1% of resistance to erythromycin but this progressively increased to 15–17% in 1994. Other European countries, such as France, Belgium or Hungary, have exceeded 25% resistance rates [6, 12]. In most countries, an association between the local prevalence of pneumococcal resistance to penicillin and macrolides has been observed. In Spain, in particular, the macrolide resistance rate of penicillin-susceptible strains is around 5%, whilst this rate increases to 20% in partially resistant pneumococci (minimal inhibitory concentrations (MICs)= 0.2–1 mg·L) to 25% in totally resistant strains (MICs ≥2 mg·L) [13]. If the resistance of S. pneumoniae to penicillin is particularly worrisome, then the resistance to macrolides implies that great care is needed when using these drugs as the first-line empirical treatment against nonsevere and nonhospitalized CAP patients [7, 14, 15]. Although no prospective studies have been published, clinical experience suggests that mild-to-moderate pneumonia caused by penicillin-resistant pneumococci can be treated with high doses of oral amoxycillin [7, 15]. In addition, penicillin and amoxycillin have higher bactericidal activity than cephalosporins [16]; this being a further argument to continue to use the former in cases of partially resistant pneumococci. Concerning macrolides, it is important to point out that strains of S. pneumoniae are either very susceptible (modal MIC 0.1–0.2 mg·L) or highly resistant to erythromycin (modal MIC ≥64 mg·L). The high erythromycin resistance caused by the action of ermAM gene indicates additional resistance to all macrolides (e.g. clarythromycin, azithromycin, roxithromycin or dirithromycin) and also lincosamides [12]. Thus, the treatment decision in CAP patients is difficult: to use penicillins at high dosage without initially covering M. pneumoniae and L. pneumophila; or to use macrolides alone with the risk of the existence of totally resistant S. pneumoniae in some cases. Which is the better policy? Since S. pneumoniae is by far the most common microbial agent causing CAP [1], the risk of not covering microorganisms is probably reduced when using penicillins at high doses instead of using macrolides. Meanwhile some newly available antibiotics can apparently overcome these problems. Furthermore, they can be administered alone at a single daily dose. The most promising are the new fluoroquinolones, such as sparfloxacin, Eur Respir J, 1995, 8, 1996–1998 DOI: 10.1183/09031936.95.08121996 Printed in UK all rights reserved Copyright ©ERS Journals Ltd 1995 European Respiratory Journal ISSN 0903 1936