Erythromycin is a macrolide antibiotic of bacteriostatic action. In high concentrations and relatively high-sensitivity microorganisms may have a bactericidal effect.

Cleocin has bacteriostatic and bactericidal activity depending on concentration of drug, infectious process and condition of an organism of the patient. Active against aerobic and anaerobic streptococcus (except for enterococci), the majority of staphylococcus except for methicillin-resistant strains, bacteroids except for Bacteroides melaninogenicus, spindle-shaped bacteria