Antibiotics (Properties, Administration, Interactions) - Posokhova K.A., Viktorov O.P. 2005

Macrolides, azalides, ketolides, streptogramins, pristinamycins
Ketolides and anhydrolides

In the ketolide molecule, the L-cladinose sugar residue at position 3 is replaced by an oxygen atom. The anhydrolide molecule also lacks the cladinose residue, and a double bond is present between carbon atoms 2 and 3 of the macrolactone ring.

A prominent representative of the ketolide group is telithromycin.

Ketolides act as inhibitors of microbial Protein Synthesis: by binding to the 50S ribosomal subunit, they disrupt the function of the peptidyl transferase center.

Ketolides exhibit virtually the same spectrum of antibacterial activity as macrolides, but with a significantly higher potency (their MIC against most Gram-positive microorganisms is substantially lower than that of erythromycin).

Ketolides and anhydrolides are highly active against erythromycin-resistant strains of cocci with the MLS-type resistance (to macrolides, Lincosamides, and Streptogramins), which has become widespread. These strains are resistant not only to erythromycin, but also to roxithromycin and azithromycin. Ketolides and anhydrolides are effective against most clinically relevant respiratory pathogens: S. pneumoniae, S. pyogenes, many Legionella species (including L. pneumophila localized in alveolar macrophages), Staphylococcus spp., H. influenzae, C. pneumoniae, and others. They show high activity against enterococci (E. faecalis, E. faecium) resistant to other macrolides (erythromycin, clarithromycin, roxithromycin), azithromycin, pristinamycin, and glycopeptides (vancomycin, etc.). In recent years, the genus Enterococcus has been thoroughly studied as a widespread multiresistant nosocomial pathogen causing severe, difficult-to-treat infections. Certain ketolide compounds are active against both macrolide-susceptible and macrolide-resistant strains of S. aureus. Their efficacy against Infections caused by N. gonorrhoeae and N. meningitidis is 4 to 10 times higher than that of erythromycin. They also affect certain mycobacteria, notably M. avium.

Indications for use. Ketolides and anhydrolides are promising agents for the Treatment of bacterial infections, particularly respiratory tract infections. In these cases, along with their antibacterial effect, the Antibiotics exhibit some anti-inflammatory activity associated with the inhibition of interleukin and nitric oxide release.



Last update: 10/08/2026

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