C One 500mg Injection is the injection form of a versatile antibiotic medicine that works by stopping the growth of infection-causing bacteria in your body. It is often injected by a doctor or a nurse either into a vein or a muscle. This medicine is used to treat many different types of infections such as those of the brain (meningitis), lungs (pneumonia), ear, abdomen, urinary tract, bones and joints, skin, blood, and heart. This medicine usually makes you feel better within a few days. Follow your doctor's instructions carefully to get maximum benefit.