What is polymyxin B used for?
Polymyxin B is an antibiotic used against certain gram-negative bacteria that are resistant to many other drugs. It is most often used as:
- A treatment for serious infections caused by susceptible gram-negative organisms, typically in hospital settings.
- A topical skin use in some formulations, where it targets bacteria on the skin surface.
How is polymyxin B given?
How it’s used depends on the product:
- Systemic use: Polymyxin B can be given by injection/IV in severe infections when the bacteria are susceptible and alternatives are limited.
- Local/topical use: Some polymyxin B products are applied to the skin for localized bacterial infections.
When doctors choose polymyxin B instead of other antibiotics
Polymyxin B is usually considered when an infection is caused by difficult-to-treat gram-negative bacteria (for example, multidrug-resistant strains) and the bacteria test as susceptible to polymyxin B.
What do patients commonly ask about with polymyxin B
People often ask about:
- Side effects: polymyxin antibiotics can affect the kidneys and can be associated with nerve or neuromuscular effects, so clinicians monitor patients closely.
- Drug susceptibility: whether the bacteria are actually sensitive to polymyxin B depends on culture and sensitivity testing.
Is polymyxin B the same as polymyxin E (colistin)?
They are related but not identical. Colistin is polymyxin E, and polymyxin B (polymyxin B) is a different agent. Clinicians choose between them based on local practice, availability, and the patient/infection context.