Some Side Effects
Ear, eye, or skin infections
Bladder infections (polymyxin B may be used for bladder irrigation)
Serious infections caused by susceptible bacteria that are very resistant to many other antibiotics (colistin and polymyxin B given by injection)
Kidney and nerve damage (when given by injection)*
* Polypeptide antibiotics are usually applied directly to the ears, skin, or eyes, but colistin and polymyxin B are sometimes given by injection when bacteria are resistant to all other antibiotics and no safer alternatives are available. Bacitracin is not available for injection.