Prescription medication · Polymyxin Antibiotic

colistin

Also sold as Coly-Mycin M. This medicine treats outer ear infections caused by bacteria.

Data updated 2026-05-15

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InteractionFew interactions
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colistin (Coly-Mycin M) is a prescription Polymyxin Antibiotic. This medicine treats outer ear infections caused by bacteria.

Cortisporin TC Otic is an ear drop medicine. It treats ear infections by killing bacteria and reducing inflammation.

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What it does

This medicine treats outer ear infections caused by bacteria.

Common side effects

No common side effects listed.

Key warnings

Neomycin can sometimes cause skin sensitivity.

The sections below are summarized in plain English from colistin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Cortisporin TC Otic contains antibiotics that kill bacteria. It also has hydrocortisone, which reduces swelling and itching. Thonzonium bromide helps the medicine penetrate the ear tissues.

Serious Warnings

Neomycin can sometimes cause skin sensitivity. This medicine may also cause hearing problems or kidney damage, but this is rare.

Known Drug Interactions

Monitor renal function in patients receiving vancomycin and concurrent and/or sequential systemic or topical use of other potentially, neurotoxic and/or nephrotoxic drugs, such as amphotericin B, aminoglycosides, bacitracin, polymyxin B, colistin, viomycin, or cisplatin.

Mechanism: Both of these drugs can be harmful to the kidneys, and using them at the same time increases the risk of kidney damage.

This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

What is in Cortisporin TC Otic?
It contains colistin sulfate, neomycin sulfate, hydrocortisone acetate, and thonzonium bromide.
How much of each medicine is in each mL?
Each mL has 3 mg of colistin base, 3.3 mg of neomycin base, 10 mg of hydrocortisone acetate, and 0.5 mg of thonzonium bromide.
Can I use this if I am allergic to any of the ingredients?
No, you should not use this product if you are allergic to any of its ingredients.
Can I use this if I have a viral infection in my ear?
No, you should not use this if you have a viral infection like herpes simplex or varicella zoster in your ear.
How long should I use this medicine?
You should limit therapy with this product to 10 days.
How do I apply the ear drops?
Lie with the affected ear upward, put in the drops, and stay in that position for 5 minutes.
Can I use a cotton wick with this medicine?
Yes, you can insert a cotton wick into the ear canal and saturate it with the suspension. Keep the wick moist and replace it every 24 hours.
What are the possible side effects?
Possible side effects include skin sensitivity, hearing problems, and kidney damage, but these are rare.
What should I do if I experience a side effect?
Contact your medical professional for advice about adverse reactions.
Where can I report suspected adverse reactions?
You can report suspected adverse reactions to Endo at 1-800-462-3636 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Does colistin interact with other medications?
The registry has 1 documented interaction rows for colistin. Notable source-record pairings include vancomycin. These rows are not a complete medication review.
What drug class is colistin?
colistin belongs to the Polymyxin Antibiotic drug class. It requires a prescription (Rx). This medicine treats outer ear infections caused by bacteria.
What pregnancy or breastfeeding source fields are listed for colistin?
The FDA label for colistin contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.

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What the FDA Data Shows for colistin

The FDA label for colistin (sold under brand names such as Coly-Mycin M) classifies it as a prescription-only medication in the Polymyxin Antibiotic class. This medicine treats outer ear infections caused by bacteria. Labeling covers dosing, contraindications, and monitoring requirements derived from clinical trials.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. Voluntary reports accumulate over the lifetime of a drug and reflect wide-ranging clinical use. The database also lists 1 documented drug interaction derived from FDA labeling, with the top-flagged interaction rated minor severity. Acquisition-cost data is surveyed weekly by CMS and updated as manufacturers report changes.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.

Last updated: August 1, 2024

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page