This product belongs to the macrolide antibiotics, which is the ethyl succinate of erythromycin. It is more stable than erythromycin in gastric acid. It has antibacterial activity against Staphylococcus (except methicillin-resistant strains), various groups of streptococci and Gram-positive bacilli. Neisseria, Haemophilus influenzae, Bordetella pertussis, etc. are also sensitive to this product. This product also has antibacterial effects on various anaerobic bacteria except Bacteroides fragilis and Fusobacterium. It also has inhibitory effects on Legionella, Campylobacter fetus, some spirochetes, Mycoplasma pneumoniae, Rickettsia and Chlamydia. This product is an antibacterial agent, but it also has a bactericidal effect on some bacteria at high concentrations. This product can penetrate the bacterial cell membrane and form a reversible bond with the 50S subunit of the bacterial ribosome near the donor site (P site), blocking the transfer RNA (t-RNA) from binding to the P site, and also blocking the displacement of the polypeptide chain from the acceptor site (A site) to the P site, thereby inhibiting bacterial protein synthesis.