Polymyxin B / Colistin
Also referenced as: Polymyxin B, Colistin, Colistimethate sodium, Polymyxin E
A family overview of two distinct cyclic lipopeptide antibiotics for susceptible Gram-negative infections.
- Evidence grade
- BModerate Human Evidence
Moderate Human Evidence
- Regulatory status
- FDA Approved for Specific Indication
FDA-approved products have specific susceptible-infection and route indications. This grouped page is not a combined product, interchangeable dose or wellness treatment.
- Human data
- Yes
Registered clinical trials exist
- Last reviewed
- October 27, 2026
Overview
A family overview of two distinct cyclic lipopeptide antibiotics for susceptible Gram-negative infections.
FDA-approved products have specific susceptible-infection and route indications. This grouped page is not a combined product, interchangeable dose or wellness treatment.
They are not interchangeable. Colistin-base and colistimethate labeling conventions create an additional medication-error risk.
Why It's Being Studied
- Gram-negative bacterial infections
- Membrane-active antibiotics
Mechanism of Action
They disrupt bacterial membranes; injectable colistimethate sodium is a prodrug of colistin, not polymyxin B.
They disrupt bacterial membranes; injectable colistimethate sodium is a prodrug of colistin, not polymyxin B. They are not interchangeable. Colistin-base and colistimethate labeling conventions create an additional medication-error risk.
From molecular target to clinical evidence
Tap each stage to see what happens.
Background: Clinical Peptide Medicines
Clinical peptide medicines include endocrine treatments, antimicrobial drugs, receptor blockers and targeted diagnostic or cancer agents. They do not share one mechanism or one set of indications.
An approval belongs to a specific medicine and indication. A diagnostic tracer, an antibiotic and a hormone are not interchangeable wellness products; read each profile's own mechanism and prescribing source.
Research Areas & Routes Studied
- Gram-negative bacterial infections
- Membrane-active antibiotics
- Product-specific injectable medicines
- Product-specific topical formulations
Evidence Summary
Established human antibacterial experience supports product-specific indications, although much systemic registration evidence is historically older.
Higher tiers carry more weight. Filled tiers have evidence for Polymyxin B / Colistin; tap to read it.
- Established human antibacterial experience supports product-specific indications, although much systemic registration evidence is historically older.
2 cited sources.
- Prescribing label2
Human clinical evidence
- Established human antibacterial experience supports product-specific indications, although much systemic registration evidence is historically older.
Reported Adverse Events in Research
- Both have serious kidney and neurological toxicity, including possible neuromuscular blockade and respiratory paralysis.
Limitations of Current Evidence
- They are not interchangeable. Colistin-base and colistimethate labeling conventions create an additional medication-error risk.
- Findings apply to the product, route and population studied; they do not establish benefits or safety for unrelated wellness uses or research-vial products.
How to Read This Research
- Is this a single molecule or a family of medicines?
- Is the use diagnostic, therapeutic or investigational?
- Does the quoted outcome match the exact product, formulation and population?
- Use the compound-specific mechanism above; this diagram describes drug development, not a shared biological pathway.
- Historical approval, present availability and off-label use are distinct questions.
- For radiopharmaceuticals and hospital medicines, specialist handling is part of the treatment context.
- Indication
- The condition and population for which a medicine is approved.
- Antagonist
- A compound that blocks activity at a receptor.
- Radiopharmaceutical
- A medicine containing a radioactive isotope for imaging or treatment.
Compare With Other Compounds
| Polymyxin B / Colistin | Trofinetide | |
|---|---|---|
| Evidence grade | B — Moderate Human Evidence | B — Moderate Human Evidence |
| Regulatory status | FDA Approved for Specific Indication | FDA Approved for Specific Indication |
| Human data | Yes | Yes |
| Clinical trials | Registered trials exist | Registered trials exist |
| Research routes | Product-specific injectable medicines, Product-specific topical formulations | Oral approved medicine |
| Cited sources | 2 | 2 |
Frequently Asked Questions
Research References
- Prescribing label
Polymyxin B / Colistin — prescribing label
- Prescribing label
Colistimethate sodium prescribing label