Editing Polymyxin (section)

== Medical use ==
Polymyxin antibiotics are relatively [[neurotoxic]] and [[nephrotoxic]], so are usually used only as a [[drug of last resort|last resort]] if modern antibiotics are ineffective or are contraindicated. Typical uses are for infections caused by strains of [[Multiple drug resistance|multiple drug-resistant]] ''[[Pseudomonas aeruginosa]]'' or [[carbapenemase]]-producing [[Enterobacteriaceae]].<ref name=Velkov2013rev/><ref name="pmid16507149">{{cite journal | vauthors = Falagas ME, Kasiakou SK | title = Toxicity of polymyxins: a systematic review of the evidence from old and recent studies | journal = Critical Care | volume = 10 | issue = 1 | pages = R27 | date = February 2006 | pmid = 16507149 | pmc = 1550802 | doi = 10.1186/cc3995 | doi-access = free }}</ref>  Polymyxins have less effect on [[Gram-positive]] organisms, and are sometimes combined with other agents (as with [[trimethoprim/polymyxin]]) to broaden the effective spectrum.<ref name=Poirel2017rev>{{cite journal | vauthors = Poirel L, Jayol A, Nordmann P | title = Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes | journal = Clinical Microbiology Reviews | volume = 30 | issue = 2 | pages = 557–596 | date = April 2017 | pmid = 28275006 | pmc = 5355641 | doi = 10.1128/CMR.00064-16 }}</ref>

Polymyxins B are not absorbed from the gastrointestinal tract, so they are only administered orally if the goal is to disinfect the GI tract.<ref name=Poirel2017rev/>  Another [[route of administration]] is chosen for systemic treatment, e.g., parenteral (often intravenously) or by inhalation.<ref name=Velkov2013rev/><ref name=Poirel2017rev/>  They are also used externally as a cream or drops to treat [[otitis externa]]  (swimmers ear), and as a component of [[triple antibiotic ointment]] to treat and prevent skin infections.<ref name=Poirel2017rev/><ref>{{cite web| vauthors = Ogbru O |title=Neomycin sulfate (Cortisporin): Drug Side Effects and Dosing|url=http://www.medicinenet.com/neomycin-polymyxin-hydrocortisone-otic_suspension/article.htm|publisher=MedicineNet|access-date=11 June 2017|language=en}}</ref>