Drug interactions
Colistin + Polymyxin b
Severity: Contraindicated
Colistin and Polymyxin b: contraindicated interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Colistin and polymyxin B are both polymyxins with similar toxicity, and combining them offers no benefit while sharply increasing the risk of kidney injury, neurotoxicity and neuromuscular blockade.
What this interaction means in plain words
Colistin and Polymyxin b are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Colistin belongs to Anti Bacterial; Polymyxin b belongs to Anti Bacterial.
Why it happens
Duplicate polymyxin therapy with additive nephrotoxic, neurotoxic and neuromuscular blocking effects.
What to do
Do not use together; choose one polymyxin. Monitor renal function and neurological status during therapy.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Colistin
Other interactions of Polymyxin b
- Cidofovir + Polymyxin b Contraindicated
- Acyclovir + Polymyxin b Major
- Adefovir + Polymyxin b Major
- Amikacin + Polymyxin b Major
- Amphotericin b + Polymyxin b Major
- Atracurium + Polymyxin b Major
Frequently asked questions
Can I take Colistin with Polymyxin b?
MediHelp rates the interaction as contraindicated. Colistin and Polymyxin b are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Colistin and polymyxin B are both polymyxins with similar toxicity, and combining them offers no benefit while sharply increasing the risk of kidney injury, neurotoxicity and neuromuscular blockade.
How serious is the interaction between Colistin and Polymyxin b?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not use together; choose one polymyxin. Monitor renal function and neurological status during therapy.
What other medicines interact with Colistin?
MediHelp also lists interactions of Colistin with, for example, Amikacin, Amphotericin b deoxycholate, Amphotericin b. The full list is on the Colistin page.
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