What is the mechanism of action of azithromycin?

Azithromycin functions primarily by inhibiting protein synthesis within bacterial cells. It belongs to the macrolide class of antibiotics, which exert their effects by binding to the 50S ribosomal subunit of the bacterial ribosome. This binding prevents the translocation step of protein synthesis, halting the growth of bacteria and leading to bacteriostatic effects. By interfering with the synthesis of proteins essential for the viability and replication of bacteria, azithromycin effectively treats various infections, particularly respiratory tract infections, sexually transmitted diseases, and certain skin infections.

The other mechanisms described in the other options do not apply to azithromycin. For instance, the inhibition of bacterial cell wall synthesis is characteristic of antibiotics like penicillins and cephalosporins rather than macrolides. Disruption of nucleic acid synthesis is associated with other antibiotic classes such as fluoroquinolones. Lastly, altering cell membrane permeability does not pertain to azithromycin's mode of action; this mechanism might relate to antibiotics like daptomycin. Understanding these distinctions helps clarify how azithromycin precisely targets bacterial cells, making it effective against specific pathogens.