From macrolides to ketolides: What is available for the treatment of outpatient respiratory tract infections?

Respiratory tract infections are a major health problem worldwide. Streptococcus pneumoniae remains the most prevalent respiratory tract pathogen. Because of the increasing prevalence of antibiotic resistance in S pneumoniae and other respiratory tract pathogens, development of new antibacterials has become necessary to treat infections that no longer respond to commonly used agents. Telithromycin, a ketolide, is a potent new oral agent designed to treat community-acquired respiratory tract infections and is especially effective against S pneumoniae strains that are resistant to penicillins and macrolides.