Does Polymyxin B / Colistin work?
Partly: some human trials, with gaps. The main trial had 406 people.
The polymyxins were approved decades before randomized trials were required, so their efficacy rests on bacteriology and observational experience. The modern controlled evidence is mostly about how to use them: the AIDA trial randomized 406 patients with carbapenem-resistant Gram-negative infections to colistin alone or colistin plus meropenem and found no difference in clinical failure. Last-resort use is well established; what is missing is trial-grade proof of benefit against modern comparators. 12
The largest randomized trial, AIDA, enrolled 406 patients in Israel, Greece and Italy. All had severe infections. The germs were Gram-negative bacteria resistant to carbapenems. Most were Acinetobacter baumannii. Patients got colistin alone or colistin plus meropenem. At 14 days, treatment had failed in 79 percent of the colistin group. In the combination group it was 73 percent. That difference was not significant. Deaths at 28 days were similar. The trial settled a long argument. Adding a carbapenem as routine does not help when the germ resists it. 1
The approved uses in the labels rest on older case series and lab data. They do not rest on controlled trials. That was the standard at the time. 2
Evidence checklist
- Randomised controlled trial AIDA randomised trial of colistin combinations
- Human study over 100 people AIDA, 406 patients
- More than one research group Article does not say who ran the trial
- Clinical outcomes, not surrogate markers Clinical failure and mortality assessed
- Human safety data beyond case reports Boxed warning; kidney and nerve toxicity known
Read the full Polymyxin B / Colistin page
More on Polymyxin B / Colistin
Citations
- Paul 2018, Lancet Infect Dis: colistin alone versus colistin plus meropenem for carbapenem-resistant Gram-negative infections (AIDA) doi.org
- Polymyxin B for injection prescribing information drugs.com
- openFDA Drugs@FDA: Coly-Mycin M (NDA 050108) approval record api.fda.gov
Reference information only, not medical advice. Drawn from the Polymyxin B / Colistin article, fact-checked against the cited sources. No dosing anywhere on this site.