Colistin 3 Million IU Injection is an antibiotic that fights bacteria. It is used to treat severe bacterial infections of the body. It is commonly used for critically ill patients admitted to the hospital. Colistin 3 Million IU Injection is given under the supervision of a healthcare professional. You should not self-administer this medicine at home. The dose and duration will be decided by your doctor based on the severity and type of infection you have. Get the injection regularly for as long as your doctor has prescribed to get maximum benefits