Your doctor may prescribe Vantin for the treatment of a bacterial infection. It is indicated to treat the following conditions: Acute exacerbation of COPD, Otitis media, Pneumonia, Rhinosinusitis, Skin infection, Streptococcal pharyngitis Vantin is an antibacterial medication that works by preventing bacterial cells from building a cell wall. The cell wall is a critical organ for bacterial cells and protects them from their environment. By preventing the formation of cell walls, Vantin slows and stops bacterial infections.