Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library

Colistin (colistimethate sodium, polymyxin E): what the evidence says

Name: Colistin (colistimethate sodium, polymyxin E)
Published: 2026-10-27

At a glance

What it is: a cyclic lipopeptide polymyxin antibiotic, given as the prodrug colistimethate sodium. The Coly-Mycin M brand is listed as discontinued; generics are marketed. ^{R1, R2, R3}

What the evidence says: Human it is a last-line drug for carbapenem-resistant bacteria. In OVERCOME trial data, adding meropenem was linked to less clinical failure, though mortality was similar (38% vs 41%). ^R4 A retrospective study compared it with other options for resistant Acinetobacter. ^R5

Biggest risks: the label warns of dose-related kidney toxicity, nerve symptoms (tingling, dizziness, slurred speech) and breathing arrest from neuromuscular blockade. ^R3

Rating


Human Human evidence	Moderate: secondary analyses and cohort data ^{R4, R5}
Animal Animal / lab evidence	Not reviewed
Regulatory	FDA-approved ^R1 · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page ^{R6, R7, R8} · not named by WADA ^R9
Established human dose	Yes, label dose (see Study details)

Evidence verdict: Multidrug-resistant Gram-negative infections: Moderate (last-resort use; mostly observational data)

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: modern evidence comes mostly from observational or secondary analyses because colistin predates modern trial standards.

What is it?

Related pages: daptomycin, ll-37.

Does it work?

Human Combination with meropenem: clinical failure 55% vs 64%. ^R4

Is it safe?

Label: nephrotoxicity, neurotoxicity, apnea. ^R3

Gray-market vials: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.

Is it legal?

US: FDA-approved, prescription (hospital); brand discontinued, generics marketed. ^{R1, R2}
Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. ^{R6, R7, R8}
Sport: not named on WADA's 2026 Prohibited List. ^R9

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
Huralska 2026 (OVERCOME data)	407 carbapenem-resistant infections	IV	Per study	Per study	Less clinical failure with meropenem	PMID 40682801

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 Drugs@FDA, Coly-Mycin M (colistimethate sodium), listed discontinued, application NDA050108 (openFDA drugsfda record checked Oct 27, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=NDA050108
^R2 Drugs@FDA, colistimethate sodium generic, application ANDA205356 (openFDA drugsfda record checked Oct 27, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=ANDA205356
^R3 Colistimethate for Injection, USP prescribing information, label published Aug 29, 2024 (DailyMed, checked Oct 27, 2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=13dc3525-1879-4bd8-a922-81bc1397d5af
^R4 Huralska M, et al. Clin Infect Dis. 2026. PMID 40682801
^R5 Raz-Pasteur A, et al. J Glob Antimicrob Resist. 2019. PMID 30557685
^R6 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R7 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R8 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
^R9 WADA. The 2026 Prohibited List, full list checked; compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Colistin (colistimethate sodium, polymyxin E). This is a prescription medicine. Use it only under the care of a licensed clinician; do not buy it from research-chemical or gray-market sellers. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).