Overview Polymyxin B is a broad-spectrum antibiotic that belongs to the polymyxin class. It is used primarily in the treatment of infections caused by gram-negative bacteria, including Pseudomonas aeruginosa, and is often utilized when other antibiotics fail or when the infection is resistant to more common antibiotics. Available in topical and injectable forms, Polymyxin B is considered a potent antimicrobial agent, especially when combined with other antibiotics to enhance effectiveness. What is Polymyxin B? Polymyxin B is a polymyxin antibiotic derived from Bacillus polymyxa, a soil bacterium. Unlike many other antibiotics, it is particularly effective against gram-negative bacteria due to…