Polypeptide antibiotics are used to treat skin infections, eye infections, and certain types of bacterial infections in the body. They also have other uses, such as treating infections in wounds and burns. These medications work by disrupting the bacteria's protective outer covering, which kills the bacteria or stops their growth. Polypeptide antibiotics come in different forms, including topical ointments and injectable solutions. Examples include bacitracin, bacitracin/polymyxin b (Polysporin), and colistimethate (Coly-Mycin M). You can choose the form that best fits your needs.