Colistimethate Sodium Injection 150 mg Per Vial (12-Pack) (RX)Colistimethate sodium is a polymyxin antibiotic designed to treat severe bacterial infections caused by certain gram negative bacteria, including Pseudomonas aeruginosa. As a prodrug, it is usually administered through injection and can also be used via oral inhalation, especially for patients with cystic fibrosis. Colistimethate injection is an antibiotic medication used for the treatment of severe or life threatening infections caused by certain