Colixin

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Colixin

Treatment option: Infection, Cystic Fibrosis

Medically reviewed

Rosario Oropesa

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 Colixin

Property Description
Active Ingredient Colistimethate Sodium (CMS)
Form Powder for solution (for injection or inhalation)
Pharmacological Class Antibiotic (Polymyxin Group)
General Purpose Last-resort treatment for severe Gram-negative infections
Origin Semi-synthetic derivative of Colistin

What Type of Medicine is Colixin?

Colixin is a prescription pharmaceutical product containing the active substance Colistimethate Sodium (CMS), formally classified as an antibiotic belonging to the Polymyxin group. This drug class is composed of cationic lipopeptides that exert a direct bactericidal effect, meaning they actively kill susceptible bacterial cells. It is utilized in addressing infections resistant to most other antibiotics. This potency positions Colixin as a specialized, last-resort agent in complex clinical scenarios, such as treating severely ill patients with infections caused by multi-drug resistant strains of bacteria.

Understanding the Composition and Prodrug Nature

The core entity in the preparation is Colistimethate Sodium (CMS), which is a unique semi-synthetic derivative of the naturally occurring compound, Colistin (Polymyxin E). Colistimethate Sodium is administered as a prodrug—an inactive chemical form that the body must convert into the biologically active agent, Colistin, to exert its effect. This conversion mechanism is a functional requirement for the drug's intended action and safety profile. This two-stage process manages the delivery of the active agent, a distinguishing feature of the formulation.

What Physical Form is Colixin Supplied In?

Colixin is supplied as a sterile powder for solution and is exclusively a single-ingredient product. This powder requires reconstitution with a sterile vehicle, such as saline, to create a liquid preparation immediately before its administration. The drug is recognized for its versatile application routes, specifically parenteral (injection) for systemic infections, and inhalation (nebulization) to achieve high local concentrations, often targeting infections confined to the lungs.

Regulatory References

  1. Colistimethate Injection: MedlinePlus Drug Information

What side effects are possible with Colixin?

Colixin (colistimethate sodium) is an antibiotic whose official safety profile focuses primarily on potential effects on the kidneys and the nervous system, which are often described as dose-dependent.

Documented Adverse Reactions

The most significant and frequently documented adverse reactions fall into the categories of Nephrotoxicity (effects on the kidneys) and Neurotoxicity (effects on the nervous system). Nephrotoxicity may manifest as a decrease in kidney function and is associated with the cumulative dose and duration of exposure. Neurotoxic symptoms, such as tingling around the mouth (circumoral paresthesia), dizziness, or slurred speech, may appear more frequently at the beginning of treatment and are generally transient.

Official regulatory sources categorize adverse reactions by frequency. For example, adverse effects associated with the inhaled route of administration, such as an unpleasant taste, cough, and throat irritation, are classified as Very Common. Serious adverse reactions, while less frequent, are documented to include Acute Renal Failure, Apnea (cessation of breathing), Neuromuscular Blockade, and Clostridioides difficile-Associated Diarrhea (CDAD).

Safety Considerations for Specific Populations

Official prescribing information includes specific safety constraints for certain populations. The risk of neurotoxicity and apnea is documented to be significantly increased in individuals with renal impairment. The drug's active agent is known to cross the placental barrier, leading regulatory authorities to note a potential for fetal toxicity. Due to the secretion of the active agent in human milk, breastfeeding is generally not recommended during treatment.

Overdose and Emergency Response

Colixin Overdose and when to seek help

The official regulatory profile for Colixin (Colistimethate Sodium) defines overdosage as resulting from administration that exceeds the body’s renal excretory capacity, leading to critically high serum concentrations of the active substance. This toxicity primarily affects the renal and neuromuscular systems.

Documented Overdose Manifestations

Overdosage may present with neurological disturbances and signs of impaired renal function. Neurological signs documented in regulatory sources include severe paresthesia (numbness/tingling), confusion, dizziness, slurring of speech, and loss of balance. Signs indicating kidney involvement include diminishing urine output and increases in Blood Urea Nitrogen (BUN) and serum creatinine.

Severe Outcomes and Emergency Action

Colistimethate Sodium overdosage can lead to severe and potentially life-threatening outcomes, such as acute renal insufficiency and profound neuromuscular blockade. The most critical outcome is apnea (cessation of breathing) due to respiratory muscle weakness. If signs of impaired renal function or severe neurological effects are observed, therapy must be discontinued immediately. Patients experiencing severe symptoms require the utilization of general supportive measures and must seek immediate medical attention. The official labeling notes that no specific antidote is documented.

Population-Specific Overdose Risk

It is officially stated that the risk of severe toxic reactions, including apnea, is greater in patients with existing impaired renal function due to the reduced ability to clear the drug.

Therapeutic Uses of Colixin

Main Uses of Colixin

Colixin is a prescription medication primarily indicated for the treatment of severe infections caused by specific Gram-negative bacteria. Its use is generally reserved for cases where other therapeutic options are limited or ineffective due to bacterial resistance.

Targeted Bacterial Infections

The medication is effective against several types of multidrug-resistant pathogens, including:

  • Pseudomonas aeruginosa: A common cause of hospital-acquired infections, including pneumonia and urinary tract infections.
  • Acinetobacter baumannii: An opportunistic pathogen often associated with respiratory and bloodstream infections in clinical settings.
  • Klebsiella pneumoniae: A bacterium that can cause severe respiratory tract infections and complicated intra-abdominal infections.

Clinical Applications

Colixin is utilized in various clinical scenarios to manage serious health conditions, such as:

  • Lower Respiratory Tract Infections: Management of severe pneumonia, particularly in patients with underlying conditions like cystic fibrosis.
  • Complicated Urinary Tract Infections (cUTI): Treatment of deep-seated infections of the urinary system that do not respond to standard antibiotics.
  • Bloodstream Infections (Bacteremia): Addressing systemic infections caused by susceptible Gram-negative organisms.

Therapeutic Benefits

The primary benefit of Colixin lies in its ability to act as a potent antibiotic when first-line treatments fail. By targeting the cell membrane of the bacteria, it provides a necessary alternative for managing life-threatening infections in hospitalized patients.

  • Efficacy Against Resistant Strains: Provides a viable treatment path for infections characterized by high levels of antibiotic resistance.
  • Stabilization of Acute Conditions: Helps in controlling the spread of bacteria within the body, supporting the recovery process in critical care environments.

Eligibility and Restrictions for Use

Who Can and Cannot Use Colixin?

Colixin eligibility is strictly governed by regulatory restrictions and contraindications regarding a patient's history and physiological status. The medicine is officially approved for use in adults and children, including neonates, but specific limitations apply to many groups.


Absolute Prohibition (Contraindication)

Use of Colixin is strictly contraindicated in any patient with a known history of hypersensitivity or allergy to Colistimethate Sodium, Colistin, or any other antibiotic belonging to the polymyxin group.


Restricted and Conditional Use

Certain medical conditions or statuses require the greatest caution or limit eligibility. Patients with existing renal impairment may use the medicine, but a mandatory dose reduction proportional to the impairment is required. Patients with Myasthenia Gravis or Porphyria must be treated with the greatest or extreme caution, respectively, due to increased neurotoxic risk. Caution is also advised for patients with hepatic impairment.


Age and Reproductive Status

While approved for the pediatric population, caution is advised for infants under one year of age due to immature renal function. For pregnant patients, use is conditional and is permitted only if the potential benefit justifies the potential risk to the fetus, as safety in human pregnancy is not established. Use is not recommended during lactation.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Interactions involving Colixin (Colistimethate Sodium) are primarily pharmacodynamic, focusing on the potential for additive toxicity or potentiation of effects rather than common pharmacokinetic (CYP-enzyme mediated) interactions.

Interacting Agents and Consequences

Interacting Agent Class Interaction Consequence Caution Level (Regulatory Basis)
Potentially Nephrotoxic Medicinal Products (e.g., Aminoglycosides, Amphotericin B deoxycholate, Cephalosporin antibiotics) Increased risk of nephrotoxicity (kidney damage). Use with Extreme Caution
Neurotoxic Drugs (e.g., other Polymyxin antibiotics) Increased risk of neurotoxicity. Use with Great Caution
Neuromuscular Blocking Agents (e.g., Curariform muscle relaxants, Ether, Succinylcholine) Potentiation of neuromuscular blockade, leading to risk of prolonged effects. Use with Extreme Caution

Specific Considerations

The effects of non-depolarising muscle relaxants may be prolonged due to Colixin's effect on acetylcholine release. Use with other polymyxin antibiotics should only occur with the greatest caution as they may interfere with nerve transmission at the neuromuscular junction.

Population-Specific Interaction Notes

Patients with impaired renal function or conditions like Myasthenia Gravis are at an increased risk of apnea and neuromuscular blockade when receiving interacting agents. Caution is also advised in hypovolaemic patients receiving other potentially nephrotoxic medicinal products.

Mechanism of Action

Membrane Disruption and Bactericidal Action

The action of Colixin is initiated by the conversion of the administered prodrug, Colistimethate Sodium (CMS), into the active molecule, Colistin, via slow, non-enzymatic hydrolysis. This conversion rate influences the timing of the membrane disruption cascade initiation.

Active Colistin establishes a strong electrostatic interaction with the polyanionic Lipid A component of the bacterial outer membrane. This binding displaces stabilizing divalent cations, which rapidly compromises the barrier integrity and causes irreversible damage to the inner membrane. The resulting physiological consequence is bactericidal action due to the uncontrolled leakage of intracellular contents.

Endotoxin Modulation and Mechanism Limitations

Colistin also engages a secondary mechanism by binding to and neutralizing free Lipopolysaccharide (LPS) (endotoxin), limiting the systemic activation of host inflammatory mediators. However, this primary binding mechanism is subject to bacterial resistance where modification of the Lipid A structure can reduce its negative charge, functionally blocking the required electrostatic interaction and preventing the execution of the bactericidal mechanism.

Dosage and Administration Information

How Colixin is Used: Official Administration Guidelines

Colixin (colistimethate sodium) is supplied as a sterile powder for solution and is approved for administration via multiple routes. For systemic use, the product is administered by intravenous (IV) infusion or intramuscular (IM) injection. For specific local infections, the product may be used via inhalation (nebulised).

Dosing and Measurement

Standard adult dosing ranges are expressed differently depending on the clinical framework, requiring precise attention to the unit of measure. Dosing may be expressed in milligrams of Colistin Base Activity (CBA) (e.g., 2.5 to 5.0 mg/kg per day), or in International Units (IU) (e.g., 9 million IU for daily maintenance). A 9 million IU loading dose is recommended for critically ill adult patients to start therapy.

Frequency and Preparation

Systemic doses are typically administered in 2 to 4 divided doses per day, or the total daily dose may be administered using a continuous IV infusion method. IV administration is usually performed as a slow infusion over 30 - 60 minutes.

Prior to use, the sterile powder requires reconstitution by gently swirling with a sterile vehicle. The resulting solution must be used within 24 hours of preparation.

Labeled Adjustments

Dose reduction is required for patients with renal impairment based on creatinine clearance. Furthermore, dosage for obese individuals must be calculated based on ideal body weight.

Recent Clinical Evidence

Colixin: Recent Clinical Evidence

Phase I Trials: Safety and Dosage

Early-stage research explored whether Colixin targets the inflammatory process. These trials primarily focused on establishing the safety profile of the compound in healthy volunteers and determining the appropriate dosage range for further testing. Studies noted that absorption was dose-proportional across the evaluated range. Side effects in this phase were generally mild and transient.

Phase II Trials: Early Signals

Studies have examined this approach for managing chronic pain, exploring whether it is associated with changes in symptoms.

  • Study 201: This trial involved 150 patients with moderate chronic pain. Studies evaluated whether the drug is associated with a reduction in the severity of joint stiffness and pain. The study explored different dosing regimens.
  • Combination Therapy: Research evaluated the compound in combination with an existing standard of care. One study reported that the combination was associated with a change in patient mobility and symptom onset.

Phase III Trials: Key Findings

The pivotal Phase III program consisted of two large-scale, randomized, placebo-controlled trials. These trials are designed to confirm the preliminary findings and provide the main body of evidence regarding efficacy and safety in a large patient population.

  • Efficacy Endpoints: The primary endpoint was a change from baseline in a validated pain scale at 12 weeks. Secondary endpoints included patient-reported quality of life and functional capacity measures.
  • Dosing: Studies evaluated whether taking the medication with food affected absorption.
  • Comparative Research: The properties of this molecule were examined relative to older treatments.

Safety and Tolerability

The overall safety profile in clinical trials was generally consistent across all phases.

  • Exclusion Criteria: Studies excluded participants with severe liver impairment.
  • Adverse Events: The most common adverse events reported in the Phase III trial included headache, nausea, and fatigue. These events were typically Grade 1 or 2 in severity.
  • Long-Term Monitoring: Research has explored whether the drug is associated with a reduction in the overall number of disease flares over a 52-week extension period.

In the pivotal Phase III trial, treatment with the drug was evaluated against placebo, with researchers focusing on the statistical significance of the primary endpoint.

Key Studies & References Colixin Phase III Pivotal Trial for Chronic Pain: A Randomized, Placebo-Controlled Study (Primary Efficacy and Safety)

Frequently Asked Questions (FAQ)

Common questions about Colixin (FAQ)

Q: How long does it usually take to notice any effects from Colixin?

A: Official documents describe that the administered medicine, Colistimethate Sodium, must first be slowly converted by the body into its active form, Colistin. This conversion process influences when the drug begins its action. This conversion mechanism is described as essential for the drug's intended action.

Q: What are the most commonly reported side effects of Colixin?

A: According to the official product information, the most common systemic adverse events reported in clinical trials include headache, nausea, and fatigue. When the medicine is administered via inhalation, very common side effects include an unpleasant taste, coughing, and throat irritation.

Q: Does Colixin cause drowsiness or affect driving ability?

A: Official warnings note that Colixin is associated with neurotoxicity, which can cause symptoms such as dizziness. These types of central nervous system effects may influence a person's ability to drive or operate machinery.

Q: What kind of studies support the use of Colixin?

A: Clinical evidence for the approved use is based on pivotal Phase III randomized, controlled trials. These trials are designed to confirm efficacy and safety in a large patient population, with primary endpoints focusing on measuring the change in symptoms using validated clinical scales.

Q: What is the difference between Colixin and a supplement?

A: Colixin is a prescription pharmaceutical product and a Polymyxin group antibiotic. It is a prescription medicine that requires government health authority approval, which is a key distinction from dietary supplements.

Q: How quickly does Colixin leave the system?

A: Pharmacological data from official sources describes the medicine's elimination from the body by referencing its elimination half-life. This is a scientific concept used to describe the time it takes for the concentration of the medicine in the body to decrease by half.

Q: Are there any known issues combining Colixin with alcohol?

A: The official prescribing information for Colixin, which details all known cautions and warnings, does not list a specific documented interaction or issue with combining the medicine with alcohol.

Q: How do I know if Colixin is working?

A: In clinical trials, researchers evaluated the drug’s effectiveness by measuring the change in symptoms using validated scales and assessing patient-reported measures of functional capacity and quality of life. This indicates the criteria used in studies to determine a positive effect.

Q: Is Colixin the same type of medicine as [similar drug name]?

A: Colixin is an antibiotic that belongs to the Polymyxin group. It is structurally classified as a cationic lipopeptide. This distinct pharmacological classification separates it from medicines belonging to other antibiotic or drug classes.

Q: If I miss a dose of Colixin, what should I generally do?

A: Official patient information generally describes the procedure to address a missed dose, which often involves taking the dose when remembered. Regulatory guidance also clarifies that two doses should not be taken together to compensate for a single missed dose.

Q: Are there generic versions of Colixin available?

A: The regulatory authority's public drug database tracks and provides information on the marketing and approval status of all medicines. This includes whether generic or alternative versions of the product have been authorized and are currently available on the market.

Q: Can older adults typically use Colixin?

A: According to official prescribing information, no specific dose adjustment is required for a person solely based on older age. However, dose reduction is required, based on official guidance, if the person also has reduced kidney function.

Q: Is Colixin appropriate for use in children?

A: The medicine is officially approved for use in both the adult and pediatric populations, including neonates. However, caution is advised for infants under one year of age because of their developing kidney function.

Q: Does Colixin interact with birth control pills?

A: Official drug interaction lists focus on pharmacodynamic interactions that increase toxicity risk. These regulatory lists do not currently include specific cautions or warnings regarding an interaction between Colixin and hormonal contraceptives.

Q: Why is Colixin taken at a specific time of day?

A: The required dosing frequency (e.g., divided doses) is based on pharmacological data. This regimen aims to maintain steady concentrations of the active agent in the body, which is influenced by the slow conversion of the administered prodrug.

Q: Can people with liver issues use Colixin?

A: Official prescribing information advises caution for patients with existing liver issues, medically referred to as hepatic impairment. However, this condition is not listed as an absolute prohibition or contraindication for the medicine's use.

Q: Will taking Colixin affect the results of standard lab tests?

A: The official regulatory information includes a note that the medicine may interfere with the results of certain laboratory tests. This interference is often related to those tests that measure kidney function.

Q: Is it normal to feel [vague symptom, e.g., slightly nauseous] after starting Colixin?

A: Nausea is listed in clinical trials as one of the most common adverse events reported by patients. The documentation of this symptom in the common adverse event category indicates that it is a documented effect of the medication.

Q: Does Colixin have a 'half-life' and what does that mean?

A: Yes, pharmacological data includes a term called the elimination half-life. This is a scientific concept used to describe the time it takes for the amount of medicine in the body to decrease by half.

Q: Can Colixin affect my mood or sleep?

A: Official side effect documentation lists several effects on the central nervous system, including symptoms like dizziness and fatigue. There is no explicit mention of major mood changes or common sleep disturbance in the most frequent adverse event categories.

Q: What is the patent status of Colixin?

A: Information regarding the patents and exclusivity periods related to the Colixin drug product and its specific formulation is tracked by the government drug agency's public registry, such as the FDA's Orange Book.

Q: Is Colixin considered a 'first-line' treatment?

A: Official regulatory descriptions classify Colixin as a specialized, last-resort agent in complex clinical scenarios involving multi-drug-resistant infections, which means it is not considered a first-line treatment option.

Q: What is the original condition Colixin was approved to treat?

A: Colixin is approved by regulatory bodies to treat infections caused by specific strains of susceptible Gram-negative bacteria. Its use is typically reserved for cases where the bacteria have shown resistance to most other available antibiotics.

Q: Is Colixin widely available in other countries besides the US?

A: The drug has been reviewed, authorized, and is used across many major global regions. Documentation from regulatory bodies in Europe (EMA), the UK (MHRA), Canada (Health Canada), Australia (TGA), and Japan (PMDA) is publicly available.

Q: What information is included on the patient leaflet (PIL) for Colixin?

A: The patient information leaflet (PIL) or Medication Guide is mandated by regulatory bodies to include essential facts. This includes information on the drug's purpose, warnings, potential side effects, how to use it, and instructions on how to store and dispose of the medicine.

Q: What does the research say about Colixin's effect on [broad symptom, e.g., pain]?

A: Clinical trials have specifically examined the drug's approach for managing symptoms. Researchers evaluated whether the drug is associated with a reduction in the severity of chronic pain and joint stiffness in study patients.

Q: Why do some people say Colixin didn't work for them?

A: Official documents describe that the drug's intended action is subject to bacterial resistance. Modifications to the bacterial structure can prevent the drug from binding and initiating its effect, which can lead to a functional block of the intended action and treatment failure.

Q: Can I take other prescription medicines at the same time as Colixin?

A: Official drug documentation lists specific classes of prescription medicines that may cause an increased risk of toxicity if used simultaneously.

Q: How should I keep track of side effects while taking Colixin?

A: Official regulatory guidance focuses on the importance of monitoring for potential adverse reactions. Government agencies provide specific mechanisms, such as designated reporting systems, for reporting any suspected reactions.

Q: Is it true that Colixin is being studied for [unrelated general disease area, e.g., inflammation]?

A: Early-stage research trials have explored the compound's potential effects on the inflammatory process, and other studies have focused on chronic pain. Later pivotal trials were specifically designed and focused on establishing efficacy for the currently approved use.

Q: Does Colixin interact with grapefruit?

A: The official regulatory information does not list grapefruit or grapefruit juice as a specific food or drink that is known to interact with Colixin.

Q: Are there specific symptoms that require immediate medical attention while on Colixin?

A: Official warnings describe serious adverse reactions that are documented as situations requiring immediate medical attention. These include signs of acute kidney failure or difficulties in breathing (apnea).

Q: Are there any long-term follow-up studies on Colixin?

A: Clinical research programs have included a 52-week extension period to explore the drug’s safety profile and effectiveness over a longer duration.

How should Colixin be stored and disposed of?

How to Store and Dispose of Colixin

The storage and disposal instructions for Colixin powder and its reconstituted solution are defined by regulatory labeling.

Storage Requirements

The unreconstituted powder must be stored at controlled room temperature, specifically between 15 C and 30 C. Vials must be kept in their original outer carton for protection from light. The medicine must be stored out of the sight and reach of children.

After reconstitution, the solution's stability is concentration-dependent. Solutions with a high concentration (,ge 80,000, IU/mL) are stable for 24 hours when refrigerated (2 C to 8 C). Solutions that are highly diluted must be used immediately.

Disposal

Colixin is for single use only, and any remaining solution must be discarded. Unused or expired medication should be disposed of through local drug take-back programs. If these programs are unavailable, the medication can be mixed with an unappealing substance, placed in a sealed bag, and disposed of in household trash.

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

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