Empirical therapy of community-acquired pneumonia: macrolides are not ideal choices.

Macrolides are a rational option for patients with community-acquired pneumonia managed as outpatients. For hospitalized patients, they may be used to supplement other drugs, usually betalactams, because of their excellent activity versus Legionella, Chlamydia pneumoniae, and Mycoplasma pneumoniae. The reason for lack of confidence for macrolides as single agents in hospitalized patients, especially for seriously ill patients, is the lack of studies confirming good results for seriously ill patients, and relatively poor in vitro activity against some important pathogens. Resistance is noted to erythromycin, clarithromycin, and azithromycin by 10% to 15% of Streptococcus pneumoniae, about 40% of penicillin resistant S pneumoniae, most Fusobacteria, some Streptococcus aureus, and all gram-negative bacilli.