Coliracin

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Coliracin

Treatment option: Infection, Cystic Fibrosis

Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Coliracin

What is Coliracin? Overview

Property Description
Active Ingredient Colistimethate Sodium
Pharmaceutical Form Powder for solution for injection/nebulization
Pharmacological Class Polymyxin-class Antibacterial (Polypeptide Antibiotic)
General Purpose Treatment of severe, multidrug-resistant bacterial infections
Origin Derived (Semi-synthetic)

What is Coliracin, and What Type of Antibiotic is It? (Identity & Classification)

Coliracin is a specialized, prescription-only pharmaceutical agent defined by its active ingredient, Colistimethate Sodium, and is officially classified as a Polymyxin-class Antibacterial. This confirms the drug belongs to a critical category of polypeptide antibiotics. The administered compound is a prodrug, which means Colistimethate Sodium must convert in vivo to yield its microbiologically potent form, Colistin (or Polymyxin E). This compound is a single-ingredient product considered to be of derived or semi-synthetic origin.


Composition and Pharmaceutical Form (Makeup & Delivery Type)

This medication is typically supplied as a sterile powder for solution for either injection or nebulization. This dual-purpose presentation is a differentiating feature, allowing healthcare providers the flexibility to address both systemic and localized pulmonary infections. The powder requires reconstitution with a sterile diluent before use. The solution is administered via parenteral routes (e.g., intravenously) for systemic effect, or via inhalation for targeted delivery to the lungs. Clinical findings consistently emphasize the importance of this agent in modern medicine, particularly its role in addressing antibiotic resistance.


The General Purpose of This Last-Resort Agent (High-Level Benefit)

The primary purpose of Coliracin is to serve as a crucial, last-resort treatment for certain types of life-threatening bacterial infections. As a bactericidal agent, its role is to directly eliminate the infecting organisms. Polymyxins are considered of critical importance for managing infections. Its necessity is clinically recognized worldwide, particularly for managing infections in vulnerable patient groups where standard therapy has failed. This agent is specifically reserved for infections caused by multidrug-resistant Gram-negative organisms.

What side effects are possible with Coliracin?

Possible side effects and safety information

The safety profile of Coliracin (Colistimethate Sodium) is primarily defined by the potential for systemic toxicities, consistent with its classification as a Polymyxin antibiotic. The documentation in regulatory sources categorizes its adverse reactions mainly by their impact on specific organ systems.

Officially Documented Adverse Reactions

The most prominent and frequently listed safety concerns involve the renal and nervous systems, often classified by government agencies as Common adverse reactions (occurring in 1% to 10% of patients).

System-Organ Class Common Adverse Reactions
Renal and Urinary Disorders Nephrotoxicity (Renal impairment)
Nervous System Disorders Neurotoxicity (e.g., Paraesthesia, dizziness, slurred speech)

Serious adverse reactions are also documented, including the potential for Acute Renal Failure and Neuromuscular Blockade that can lead to Respiratory Arrest (Apnoea). These are clinically significant, though less frequent, effects noted in regulatory prescribing information.

Safety Considerations and Restrictions

Official labeling emphasizes that the risk of Nephrotoxicity is typically dose-dependent and increases with the duration of exposure. Furthermore, there are specific constraints for patient populations:

  • Pre-existing Renal Impairment: Patients with reduced kidney function are at an increased risk of toxicity, necessitating specific dose adjustment requirements as defined in regulatory labels.
  • Contraindications: The medicine is strictly contraindicated in individuals with a known allergy to Polymyxins and in patients with a history of Myasthenia Gravis due to the high risk of severe neuromuscular blockade.

Regulatory texts also specify that specific local effects, such as bronchospasm, may occur when the medicine is delivered via inhalation, linking safety concerns to the route of administration.

Overdose and Emergency Response

Overdose and when to seek help

Coliracin (Colchicine) has a narrow therapeutic index, meaning the difference between a therapeutic dose and a toxic dose is small, and overdose carries a high risk of severe toxicity and mortality.

Clinical Manifestations of Overdose

Symptoms may be delayed for up to 12 hours after ingestion. The clinical course is often described in three phases:

  • Early Phase (0–24 hours): Profound gastrointestinal symptoms including severe nausea, vomiting, abdominal pain, and often profuse, bloody diarrhea. This can lead to significant fluid loss and shock.
  • Intermediate Phase (1–7 days): Multi-system failure, including bone marrow depression, acute renal and hepatic failure, respiratory distress, and cardiac arrhythmias.
  • Recovery Phase (After 7 days): Recovery may be accompanied by effects like alopecia (hair loss).

Required Emergency Actions

IMMEDIATE MEDICAL ATTENTION IS REQUIRED for all known or suspected ingestions of an overdose, or if any symptoms of toxicity appear. Due to the delayed onset of severe effects, all patients must be referred for immediate medical assessment and should be monitored for at least 24 hours in a healthcare setting.

There is no specific antidote for Coliracin (Colchicine) overdose. Management is primarily supportive care to address multi-organ effects. In certain cases and if ingestion was recent, measures such as gastric decontamination with activated charcoal may be utilized.

Therapeutic Uses of Coliracin

Coliracin (colistimethate) is an approved antibacterial medication used to manage acute or long-term infections associated with specific types of gram-negative bacteria. This therapy helps address conditions caused by sensitive strains of microorganisms, including Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli, and Klebsiella pneumoniae.

Coliracin functions to support the body in controlling bacterial proliferation within the infection site. It is generally reserved for use when other standard anti-infective options are not suitable or have been found to be less effective against the identified susceptible bacteria. The goal of using Coliracin is to support the patient's recovery and promote a positive outlook during serious bacterial conditions. Its use supports a therapeutic regimen for various susceptible gram-negative pathogenic bacilli.

Quick Facts

  • Therapeutic Domain: Treatment of acute or chronic infections linked to susceptible strains of gram-negative bacilli.
  • Primary Use: Helps address conditions associated with Pseudomonas aeruginosa.
  • Goal: To support the patient in controlling bacterial growth.

Eligibility and Restrictions for Use

Who Can and Cannot Use Coliracin? (Population Eligibility Rules)

Official regulatory documents define strict population-eligibility rules for the use of Coliracin (Colistimethate Sodium), primarily based on the risk of toxicity and the patient's existing health status.

Absolute Non-Eligibility (Contraindications)

This medicine is contraindicated and must not be used in patients with a documented history of hypersensitivity to Colistimethate Sodium or any other Polymyxin-class antibiotic, including Colistin or Polymyxin B. It is also explicitly contraindicated for patients diagnosed with Myasthenia Gravis due to the risk of severe neuromuscular blockade.


Conditional and Restricted Use

Use is restricted in several populations, mandating caution or dose modification:

  • Renal Impairment: Patients with any degree of impaired kidney function require a dosage reduction proportional to the extent of impairment to prevent acute renal insufficiency. The drug's elimination is heavily dependent on renal function.
  • Age Groups: Caution is advised for infants under one year of age due to immature renal function, and for older adults due to the increased frequency of age-related decline in kidney function.
  • Pregnancy and Lactation: Use during pregnancy is conditional, permitted only if the potential benefit justifies the potential risk to the fetus, as the drug is known to cross the placental barrier. Caution is exercised for use in nursing women.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Coliracin (Colistimethate Sodium) has officially documented interaction patterns that primarily relate to the potential for reinforcing specific toxic effects and interfering with elimination pathways. The regulatory profile mandates strict cautions or prohibitions regarding co-administration with certain medicinal products.


1. Pharmacodynamic Reinforcement of Toxicity

Co-administration with other nephrotoxic or neurotoxic medicinal products is officially documented to increase the risk of summative toxicity. Concomitant use with drugs of nephrotoxic potential, such as Aminoglycoside Antibiotics and Polymyxin B, should be avoided. Furthermore, Coliracin potentiates the effects of curariform and non-depolarising muscle relaxants, leading to an increased risk of neuromuscular blockade and apnea.

2. Pharmacokinetic and Elimination Considerations

Regulatory cautions note the potential for altered exposure when Coliracin is co-administered with medicinal products known to inhibit or induce drug metabolising enzymes or that act as substrates for renal carrier mechanisms.

3. Specific Restrictions and Cautions

Official labeling mandates that co-administration with Sodium Cephalothin must be avoided due to the enhanced risk of nephrotoxicity. In specific populations, such as patients with Impaired Renal Function or Myasthenia Gravis, co-treatment with certain antibiotics, including macrolides or fluoroquinolones, requires greater caution due to the heightened risk of neuromuscular blockade.

Mechanism of Action

Primary Mechanism: Outer Membrane Destabilization and Lysis

Coliracin's active form, Colistin (Polymyxin E), functions as a membrane-active, cationic molecule. The mechanism initiates with the drug binding electrostatically to the negatively charged Lipopolysaccharide (LPS) layer, specifically the Lipid A component, located within the Outer Membrane (OM) of Gram-negative bacteria. This binding displaces the Ca^2+ and Mg^2+ ions required for OM stability, causing the membrane to destabilize and become permeable.

Following the OM breach, Colistin's hydrophobic regions insert into the underlying Cytoplasmic Membrane, causing physical disruption of the lipid bilayer in a detergent-like fashion. This irreparable structural damage leads to the immediate leakage of essential intracellular components and the failure of osmotic regulation, culminating in bacterial cell lysis (rupture) and a bactericidal effect.

This mechanism is highly specific to the LPS-Outer Membrane target, rendering the drug inactive against Gram-positive bacteria. Furthermore, bacterial resistance can arise from chemical modification of Lipid A, which reduces the negative charge and physically impedes Colistin binding.

Dosage and Administration Information

How to Use Coliracin

Colistimethate Sodium (Coliracin) is administered according to strict protocols focusing on specific routes, calculated dosing, and administration schedules. The medication is supplied as a powder for solution and requires reconstitution using an approved sterile diluent under strict aseptic technique before use.


Official Routes and Schedules

Coliracin may be administered via two primary routes based on the site of infection:

Administration Route Frequency Pattern Key Procedural Instruction
Intravenous (IV) Infusion Divided daily dosing (typically 2 to 3 times per day) IV administration is required to be delivered by slow infusion over 30 to 60 minutes.
Inhalation (Nebulization) Defined course, up to 3 times per day Used for targeted delivery to the lungs for pulmonary infections.

Dosing and Population Adjustments

Systemic dosing begins with a calculated loading dose (e.g., 9 million International Units [IU] or approximately 300 mg Colistin Base Activity [CBA]) to rapidly achieve therapeutic levels, followed by a maintenance dose. Dosing is standardized using IU (European) or mg CBA (U.S.) and must be precisely calculated by the healthcare provider.

Crucially, the maintenance dose must be adjusted in direct proportion to the patient's degree of renal impairment (reduced creatinine clearance) to mitigate potential accumulation. For children weighing 40 kg or less, a specific weight-based regimen (e.g., 75,000–150,000 IU/kg/day) is utilized. If a dose is missed, it should be taken as soon as remembered, but double doses are strictly prohibited. The entire administration process is generally performed under the supervision of physicians experienced with specialized antibacterial agents.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Coliracin


Evidence for Intravenous Use in Severe Systemic Infections

This section summarizes the available evidence on the use of Coliracin when it is delivered directly into the bloodstream for treating severe, body-wide infections caused by multidrug-resistant bacteria. Research for this use primarily focuses on conditions that are often difficult to manage with other treatments. The types of bacteria studied include Acinetobacter baumannii and Pseudomonas aeruginosa.

The research landscape is characterized mainly by observational cohort studies and retrospective analyses. A limited number of randomized controlled trials (RCTs) have been conducted. Researchers monitored key outcomes, including measures of clinical indicators (signs that the infection is changing) and all-cause mortality over short periods, typically 14 or 28 days.

Studies report measurements of all-cause mortality and clinical status indicators among patient groups receiving Coliracin therapy. Findings varied across different observational cohorts. Research highlights changes measured during the study period, but these findings describe group patterns, and research does not determine whether an individual will respond similarly.


Evidence for Inhaled Use in Chronic Pulmonary Infections

This part details the research involving Coliracin administered via nebulization to the lungs. This approach was studied for the management of chronic lung infections, especially those caused by Pseudomonas aeruginosa. This research has primarily focused on adult and pediatric patients with Cystic Fibrosis (CF) who have persistent lung infections.

Researchers have utilized randomized controlled trials (RCTs) to evaluate this delivery method. Studies focused on outcomes related to lung function (measured by changes in Forced Expiratory Volume in 1 second ( FEV1)) and examined outcomes describing episodic or acute changes, such as the number of pulmonary exacerbations (flare-ups of the infection).

Studies report how lung function ( FEV1) and frequency of flare-ups evolved in the observed populations. Reported microbiological findings show patterns related to the bacterial density in sputum samples. Research has also explored the use of inhaled Coliracin in patients with non-CF Bronchiectasis.


What is Still Uncertain About Coliracin Research

Research provides context but not individual predictions, and evidence highlights what is known—and what is still uncertain. Evidence quality varies across studies, particularly for systemic use, where reliance on observational data means that certainty remains low compared to definitive, large-scale randomized trials. Sample sizes were modest in earlier trials, and follow-up durations were limited, restricting the ability to fully characterize long-term outcomes. The comparative evidence is lacking for certain clinical scenarios, and research provides limited insight into optimal dosing for individuals.

Frequently Asked Questions (FAQ)

Common questions about Coliracin (FAQ)

Q: Can Coliracin be used by people who have other health conditions?

A: Official documents mandate caution or restrictions for patients with certain pre-existing conditions. For instance, the medicine is officially contraindicated (must not be used) in patients with Myasthenia Gravis. Furthermore, official product information specifies that dose adjustment is required for patients with impaired kidney function to mitigate the risk of toxicity.


Q: What if I accidentally took too much Coliracin?

A: Official drug information states that an excessive amount may lead to increased neurotoxic effects. These effects may include confusion, dizziness, or muscle weakness, and in severe cases, the risk of respiratory arrest (apnea) is noted. Regulatory documents emphasize that high drug levels can result from accidental overdose or incorrect dose adjustment for kidney impairment.


Q: Is Coliracin safe to take if I am already taking [General class of drug, e.g., a common pain reliever]?

A: Official drug interaction lists focus on specific specialized medications known to increase the risk of toxicity, such as other nephrotoxic (kidney-damaging) or neurotoxic drugs. Regulatory guidance does not typically list common pain relievers, but it is noted that caution is required when the medicine is co-administered with agents known to affect the kidneys.


Q: Are there any known issues with Coliracin and kidney or liver function?

A: Yes, Coliracin is strongly associated with Nephrotoxicity (kidney impairment). Official product information specifies that dose adjustment is required for patients with reduced kidney function. Regulatory texts also advise caution when the medication is used in patients with hepatic (liver) impairment, though specific dose changes for liver issues are not typically required.


Q: Is Coliracin only used for the condition listed in the main description?

A: The official indications state that Coliracin is approved for the treatment of infections caused by sensitive strains of certain Gram-negative bacteria. These include specific organisms such as P. aeruginosa, E. coli, and K. pneumoniae. The official purpose centers on these critical bacterial infections.


Q: Does Coliracin start working right away, or does it take a while?

A: According to regulatory pharmacokinetics data, Colistimethate Sodium (the pro-drug) is converted to its active form, Colistin, very rapidly in the body. When administered intravenously, peak concentrations of the active drug in the blood are generally reached within about 10 minutes, indicating that drug concentrations are quickly established.


Q: How long does the effect of one dose of Coliracin usually last?

A: Official drug information describes the duration of the active drug, Colistin, using its serum half-life. This half-life (the time required for half the dose to be cleared from the blood) is approximately 1.5 to 3 hours, depending on the route of administration.


Q: Do the side effects of Coliracin usually go away after the first few days?

A: Regulatory documents note that neurotoxic adverse reactions, such as dizziness or tingling sensations, often appear within the first few days of starting treatment. Official information suggests that these effects are expected to resolve once the use of the medicine is discontinued.


Q: Is [Specific minor side effect, e.g., mild headache] considered a normal reaction to Coliracin?

A: Yes, headache is explicitly listed in official product information as a very common adverse reaction. This is recognized as one of the neurotoxic effects associated with the drug.


Q: Can taking Coliracin cause me to feel tired?

A: Official drug labeling notes that symptoms such as unusual tiredness or weakness (fatigue) can be signs of potential adverse reactions. This symptom may be related to more serious effects like kidney problems or imbalances in the body's electrolytes.


Q: Is there any risk of becoming dependent on Coliracin?

A: Regulatory agencies, such as the DEA, have not classified Coliracin as a controlled substance. This non-scheduled status is used as an indicator that the medication has a low potential for abuse or dependency.


Q: Can Coliracin affect my ability to drive or operate machinery?

A: Yes, official warnings state that neurotoxic effects like dizziness, vertigo, or slurred speech may occur during treatment. For this reason, official warnings advise that patients should avoid driving vehicles or operating hazardous machinery while on therapy.


Q: Are there different strengths or versions of Coliracin available?

A: Coliracin is typically supplied as a sterile powder for solution that requires mixing before use. Regulatory sources commonly specify a single strength for the vial, often designated by an equivalent amount of Colistin Base Activity (CBA) or International Units (IU).


Q: Is Coliracin considered a short-term or a long-term treatment?

A: Official prescribing information describes Coliracin as a treatment intended for a specific, generally short-term course to manage acute, severe bacterial infections. The dosing regimens and efficacy studies published in regulatory documents reflect these limited treatment durations.


Q: Do the research studies on Coliracin show consistent results?

A: Regulatory reviews of the clinical evidence often note that the data, especially for intravenous use, are limited and derived mostly from observational studies. Official summaries indicate that study findings regarding efficacy and outcomes have sometimes varied across different patient groups or research cohorts.


Q: Is Coliracin new, or has it been around for a while?

A: Colistimethate Sodium, the active ingredient in Coliracin, is a long-standing medication. Official approval records indicate that the original formulation was approved prior to 1982, indicating its long history as an agent in the Polymyxin class of antibiotics.


Q: Why do doctors prescribe Coliracin instead of other treatments?

A: Official documents describe Coliracin as a crucial agent reserved for use when other, more conventional antibiotics are not effective or not appropriate. It is reserved for use against multidrug-resistant Gram-negative organisms.


Q: Has Coliracin been approved in countries outside of the United States?

A: Yes, Colistimethate Sodium is an internationally recognized medication. It is approved and regulated by numerous government authorities globally, including the European Medicines Agency (EMA) and Health Canada.


Q: Are there specific times of day when Coliracin is usually taken?

A: Official instructions specify that Coliracin is administered in divided doses (such as two or three times a day) or as a continuous infusion, depending on the route. The regulatory label does not mandate a specific time of day; administration is timed according to the prescribed frequency.


Q: Can children or teenagers use Coliracin?

A: Yes, the official prescribing information includes specific, weight-based dosage regimens for the use of Coliracin in pediatric patients. However, due to immature kidney function, official information notes that caution is required for infants under one year of age.


Q: How long after stopping Coliracin might the medication stay in my system?

A: Based on the drug's pharmacokinetic data, the active drug (Colistin) has a relatively short half-life in the blood, measuring approximately 1.5 to 3 hours. Because of this, the majority of the medication is typically eliminated from the body within about a day after the last dose.


Q: Is there a generic version of Coliracin available?

A: Yes, the active ingredient in Coliracin, Colistimethate Sodium for injection, has approved generic versions. This information can be confirmed by regulatory agencies such as the FDA.


Q: Are there any reports of Coliracin causing changes in mood or behavior?

A: Yes, official documents describe that severe neurotoxic effects associated with the medication can include mental confusion and psychosis. Furthermore, symptoms of overdose noted in regulatory information may include specific changes in a person's mood or mental state.


Q: What are the reasons someone might need to stop taking Coliracin?

A: Regulatory documents instruct that the use of Coliracin should be stopped immediately if certain serious adverse reactions are suspected. These reactions include signs of impaired kidney function, a severe hypersensitivity reaction (allergy), or suspected severe neuromuscular blockade.


Q: Can I crush or split the Coliracin tablet/capsule?

A: Coliracin is not supplied as a tablet or capsule. According to official labeling, it is provided as a sterile powder that must be reconstituted (mixed) with a sterile liquid by a healthcare professional. It is then administered via injection or nebulization.


Q: Does the evidence suggest Coliracin is better for certain groups of people?

A: While the official documents do not use comparative language, the clinical evidence often specifically focuses on its use in certain groups. For example, a large body of research is documented regarding its efficacy in adult and pediatric patients with Cystic Fibrosis (CF) who have chronic lung infections.


Q: Is Coliracin considered a scheduled or controlled substance?

A: No, Coliracin (Colistimethate Sodium) has not been classified as a controlled substance by the DEA. This determination is made by government agencies, such as the DEA, based on the potential for abuse.


Q: Do I need a prescription to get Coliracin?

A: Yes, Coliracin is designated as a prescription-only medicine. Regulatory agencies restrict the sale and distribution of this drug, and it requires a valid prescription from a licensed healthcare provider.


Q: If I feel better, is it okay to stop Coliracin early?

A: Regulatory documents explicitly warn against stopping the medication early, even if symptoms improve. Official information states that stopping the course early may increase the risk of the infection returning or the development of drug-resistant bacteria.

How should Coliracin be stored and disposed of?

How to Store and Dispose of Coliracin?

The storage of Coliracin (Colistimethate Sodium powder) is subject to specific regulatory requirements to maintain its quality.


Storage Requirements

  • Unopened Powder: Store the powder at a Controlled Room Temperature, typically 20 C to 25 C (68 F to 77 F), and ensure it does not freeze.
  • Light Protection: Keep the vial in its original outer carton to protect the contents from light.
  • Reconstituted Solution: After mixing, the solution should ideally be used immediately. If necessary, it may be stable for up to 24 hours when refrigerated at 2 C to 8 C, depending on the concentration.
  • Child Safety: The medicine must be stored out of the sight and reach of children.

Disposal Instructions

Coliracin is for single use only. Any prepared solution that is unused or expired must be discarded. Disposal of the remaining product or waste material should be conducted in accordance with local regulatory requirements for pharmaceutical waste.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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