Colistimethate Injection
Colistimethate injection is an antibiotic used to treat serious bacterial infections caused by certain gram-negative bacteria, including Pseudomonas aeruginosa, E. coli, Klebsiella pneumoniae, and Enterobacter aerogenes.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 6 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Colistimethate Injection: Patient Information Guide
A plain-language walkthrough of Colistimethate Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Colistimethate for Injection is an antibiotic used to treat serious bacterial infections caused by certain gram-negative bacteria. It is available as Coly-Mycin, given by intramuscular or intravenous injection.
- Infections caused by Pseudomonas aeruginosa — this is a primary indication
- Infections caused by Escherichia coli (E. coli)
- Infections caused by Klebsiella pneumoniae
- Infections caused by Enterobacter aerogenes
- Serious infections strongly suspected to be caused by gram-negative bacteria (used to start treatment while awaiting lab confirmation)
- Not for infections caused by Proteus or Neisseria
⚙️How it works▾
Colistimethate sodium acts like a surface detergent that punches through the outer membrane of certain bacteria. Once it disrupts that protective barrier, the bacteria can no longer keep their internal environment stable — and they die. This makes it a bactericidal antibiotic, meaning it kills bacteria rather than just slowing their growth.
It is active against aerobic gram-negative bacteria specifically — a group that includes some of the most difficult-to-treat hospital-acquired infections. To protect the long-term effectiveness of this antibiotic, it should only be used when there is good reason to believe the infection is caused by a susceptible organism.
💊How it's taken▾
Coly-Mycin is given by injection — either into a vein (IV) or a muscle (IM) — by a healthcare professional. It is usually administered in divided doses, spread out two to four times per day, depending on the severity of the infection and the patient's kidney function.
- Dosing is weight-based and individualized — your prescriber determines your schedule
- In patients with kidney impairment, the dose and frequency are reduced to prevent toxicity
- In obese patients, dosing is based on ideal body weight, not actual body weight
🤒Side effects — in detail▾
Like all medications, colistimethate can cause side effects. The most commonly reported ones include:
- Tingling or numbness in the hands, feet, or tongue
- Dizziness or vertigo
- Slurred speech
- Generalized itching, hives, or rash
- Nausea or gastrointestinal upset
- Fever
- Decreased urine output or changes in kidney labs (elevated BUN and creatinine)
More serious reactions — including difficulty breathing, signs of kidney failure, severe diarrhea, dangerous electrolyte imbalances, or allergic reactions — require immediate medical attention.
⚠️Warnings & precautions▾
- Kidney damage (nephrotoxicity): This is dose-related and usually reversible after stopping the drug, but it requires close monitoring — especially in patients with pre-existing kidney disease.
- Respiratory arrest: Stopping breathing has been reported after intramuscular injection, particularly in patients with reduced kidney function. Emergency support must be available.
- Neurological effects: Tingling, dizziness, and slurred speech can occur. Do not drive or operate machinery during treatment.
- Electrolyte abnormalities: IV use has been linked to low potassium, calcium, and magnesium (a condition called Pseudo-Bartter syndrome). Electrolytes should be monitored during treatment.
- C. difficile-associated diarrhea (CDAD): Severe or bloody diarrhea during or up to two months after treatment may signal a dangerous gut infection requiring separate treatment.
- Overdose risk: Too much can cause neuromuscular blockade, respiratory paralysis, and acute kidney failure.
🔀What it interacts with▾
Colistimethate can interact with several other drugs, increasing the risk of serious side effects. Key interactions include:
- Aminoglycoside antibiotics (e.g., gentamicin, tobramycin) and polymyxins — can add to nerve and muscle transmission problems; use together only with extreme caution
- Curariform muscle relaxants (e.g., tubocurarine, succinylcholine, gallamine, decamethonium) — significantly intensify neuromuscular blockade (muscle paralysis risk); use with extreme caution
- Ether and sodium citrate — also enhance neuromuscular blockade; use with extreme caution
- Sodium cephalothin — increases the risk of kidney damage; this combination should be avoided
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Tell your doctor if you have ever had an allergic reaction to colistimethate sodium or any component of the injection
- Tell your doctor if you have kidney disease — dosing must be adjusted and kidney function monitored closely
- Disclose all other medications, especially antibiotics and muscle relaxants, to avoid dangerous interactions
- Do not drive, operate machinery, or do tasks requiring full alertness during treatment — neurological side effects like dizziness and tingling can impair your ability to do so safely
- This medication is used in both adults and children, including premature infants — dosing is individualized by weight and kidney function
🚑If you take too much▾
Taking too much colistimethate can cause neuromuscular blockade — meaning the muscles, including breathing muscles, may stop working properly. This can lead to confusion, loss of coordination, slurred speech, and in severe cases, respiratory arrest and death. It can also cause acute kidney failure, seen as reduced urine output and rising creatinine levels.
If an overdose is suspected, the drug should be stopped immediately and supportive medical care provided. Whether dialysis can remove colistimethate from the body in an overdose situation is not known.
📡Pharmacodynamics — effects in the body▾
Colistimethate sodium disrupts the cell membrane of susceptible gram-negative bacteria, causing the membrane to break down and the bacteria to die. It has demonstrated bactericidal activity — meaning it kills bacteria outright — against organisms including Pseudomonas aeruginosa, E. coli, Klebsiella pneumoniae, and Enterobacter aerogenes. This activity has been confirmed both in laboratory testing and in clinical infections.
🔬Pharmacokinetics — how your body processes it▾
After a single dose given either intravenously (IV) or intramuscularly (IM), colistimethate reaches its peak concentration in the blood quickly — IV gives a higher peak at 10 minutes than IM. The drug is then cleared from the bloodstream with a half-life of about 2 to 3 hours in both adults and children, including premature infants. It is excreted through the urine, where it achieves high concentrations for several hours after dosing.
📦How to store it▾
Store unreconstituted product between 20° to 25°C (68° to 77°F). Store reconstituted solution in refrigerator 2° to 8°C (36° to 46°F) or between 20° to 25°C (68° to 77°F) and use within 7 days.
📄 Written from Colistimethate Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
Supplements & herbs that interact with Colistimethate Injection
27 supplements and herbal products have documented interactions with Colistimethate Injection in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Moderate · 26
- Minor · 1
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nutrient depletion considerations
Colistimethate Injection has been associated with lower levels of 7 nutrients in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.
- Higher significance · 6
- Moderate · 1
Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Colistimethate Injection — the kind of thing our pharmacy team would talk through with you at the counter.
What kind of infections does this medication treat? ▾
How will I receive this medication — will I get it at home or in the hospital? ▾
What side effects should I actually watch out for? ▾
Is it safe to drive while I'm being treated with this drug? ▾
I've heard antibiotics can cause diarrhea — is that something to worry about here? ▾
My kidneys aren't 100% — is this medication safe for me? ▾
Is Colistimethate Injection available over the counter? ▾
When was Colistimethate Injection first available? ▾
Who makes Colistimethate Injection? ▾
💬 Answers drafted from Colistimethate Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Colistimethate Injection comes
Colistimethate Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Injection
How this form is used
- Coly-Mycin is used to treat acute or chronic infections caused by susceptible gram-negative bacteria, including Pseudomonas aeruginosa, E. coli, Klebsiella pneumoniae, and Enterobacter aerogenes
- Coly-Mycin may be used to start treatment in serious infections strongly suspected to be caused by gram-negative bacteria while awaiting lab results
- Coly-Mycin is given by injection into a vein (intravenous) or into a muscle (intramuscular) — your healthcare team will administer it
- Coly-Mycin is typically given in divided doses throughout the day; frequency is adjusted based on kidney function
- Coly-Mycin vials must be reconstituted (mixed) with sterile water before use and should be inspected for particles or discoloration before administration
- Coly-Mycin dosing in patients with kidney impairment must be reduced — your prescriber will determine the right schedule based on your kidney function
📊 Colistimethate Injection across the U.S. market
How Colistimethate Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Colistimethate Injection is used
A general measure of how commonly Colistimethate Injection is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Colistimethate Injection is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Colistimethate Injection prescribed? Of the 1,597 medications we measure, Colistimethate Injection ranks #1,298 by Medicaid prescriptions — more than 19% of them.
Utilization by Colistimethate Injection product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
Other Colistimethate Injection products — combination packs and listings not yet matched to a specific clinical product (kept visible so every prescription is accounted for)
Summed across the 5 of 32 listed NDC products with Medicaid activity.
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Colistimethate Injection, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 5 of 32 listed Colistimethate Injection NDCs with Medicaid activity.
🔍 Compare Colistimethate Injection products
A representative set of FDA-listed product records for Colistimethate Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 150 mg/2 mL | Intramuscular, Intravenous | Fresenius Kabi USA, LLC | ANDA | View NDC → |
| 150 mg/4 mL | Intramuscular, Intravenous | Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. | ANDA | View NDC → |
| 150 mg/4 mL | Intramuscular; Intravenous | Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. × 2 listings | ANDA | View NDC → |
| 150 mg | Intramuscular, Intravenous | Hikma Pharmaceuticals USA Inc. | ANDA | View NDC → |
| 150 mg | Intramuscular; Intravenous | Nexus Pharmaceuticals Inc | ANDA | View NDC → |
| 150 mg/2 mL | Intramuscular, Intravenous | Par Health USA, LLC | NDA | View NDC → |
| 150 mg/2 mL | Intramuscular; Intravenous | Par Pharmaceutical, Inc. | NDA | View NDC → |
| 150 mg/2 mL | Intramuscular; Intravenous | Par Pharmaceutical, Inc. | NDA AUTHORIZED GENERIC | View NDC → |
| 150 mg/6 mL | — | Patheon Manufacturing Services LLC | DRUG FOR FURTHER PROCESSING | View NDC → |
| 150 mg/2 mL | Intramuscular; Intravenous | X-GEN Pharmaceuticals, Inc. | ANDA | View NDC → |
| 150 mg/2 mL | Intramuscular; Intravenous | Xellia Pharmaceuticals ApS | ANDA | Find on DailyMed ↗ |
| 150 mg | Intramuscular, Intravenous | Xellia Pharmaceuticals USA LLC × 2 listings | ANDA | View NDC → |
| 150 mg | Intramuscular; Intravenous | Xellia Pharmaceuticals USA LLC × 3 listings | ANDA | View NDC → |
| 150 mg/2 mL | Intramuscular; Intravenous | XGen Pharmaceuticals DJB, Inc. | ANDA | View NDC → |
Showing 18 of 18 products — FDA National Drug Code Directory. See every product, package size and price: browse all 18 Colistimethate Injection NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Colistimethate Injection — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Colistimethate Injection in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Colistimethate Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
📦 Supply & shortage status
Whether Colistimethate Injection is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Colistimethate Injection belongs to the Polymyxin-class Antibacterial class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 6 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Par Pharmaceutical, Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.