ABSTRACT
Erythromycin, the first member of the macrolide class to enter clinical use, was introduced in 1952. Erythromycin remained a mainstay antibiotic for several decades both as an inpatient, infusible agent and as an outpatient, orally administered drug until the introduction of the newer macrolide and azalide agents, clarithromycin and azithromycin, in the early 1990s. The macrolide antibiotic class has activity against each of the major pyogenic pathogens playing etiologic roles in respiratory tract infections: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Moreover, they are potent against atypical respiratory tract pathogens: Legionella pneumophila,Mycoplasma pneumoniae, and Chlamydia pneumoniae. As such they comprise a class of agents with focused activity against respiratory pathogens. It is important to note that they have little role in the treat-
ment of skin and soft tissue infections for which staphylococci are common causes, enteric infections caused by gram-negative bacilli, or opportunistic gram-negative infections such as Pseudomonas aeruginosa. Hence, macrolides are considered excellent focused therapy agents for use against respiratory tract infections.
