What are macrolides active against?
To treat mild to moderate infections of the respiratory tract, sinuses, gastrointestinal tract, skin, soft tissue, diphtheria, impetigo contagiosa, STIs. Currently available macrolides are erythromycin and the newer agents clarithromycin, azithromycin, roxithromycin, dirithromycin, and telithromycin. Generally, macrolides are active against gram-positive cocci (mainly staphylococci and streptococci) and bacilli, and less against gram-negative bacteria. With the exception of Bordetella pertussis, Campylobacter, Chlamydia, Helicobacter, and Legionella species, gram-negative bacilli are generally resistant to the macrolides. Macrolides are also active against Mycobacteria, Mycoplasma, Ureaplasma, spirochetes, and other organisms. Macrolides inhibits RNA-dependent protein synthesis by reversibly binding to the 50 S ribosomal subunits of susceptible microorganisms.