Colistin

Colistin

• Colistin, also known as polymyxin E, is an antibiotic medication used to treat serious bacterial infections.
• It belongs to the class of polymyxin antibiotics and is particularly effective against multidrug-resistant gram-negative bacteria.
• Colistin is primarily used when other antibiotics have failed or are not suitable for the treatment of these resistant infections.

Colistin

Mechanism of Action

• Colistin acts by disrupting the structure and function of bacterial cell membranes.
• It has a detergent-like effect, causing disruption and leakage of the outer and inner cell membranes of bacteria.
• This leads to the death of the bacterial cells.
• Colistin primarily targets gram-negative bacteria, including strains that are resistant to many other antibiotics.
• It binds to the lipid components of the bacterial cell membrane, particularly lipopolysaccharides, disrupting their integrity and resulting in cell death.

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Medical Uses

Colistin is used in the treatment of serious bacterial infections caused by gram-negative bacteria that are resistant to other antibiotics. It is commonly reserved for infections caused by multidrug-resistant organisms, such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae.

Colistin_Function

Some of the specific medical uses of colistin include:

• Hospital-Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP): Colistin is used to treat bacterial pneumonia that develops during a hospital stay or in patients who are on mechanical ventilation.
• Urinary Tract Infections (UTIs): In certain cases of UTIs caused by multidrug-resistant gram-negative bacteria, colistin may be used as a treatment option.
• Bloodstream Infections: Colistin is sometimes used for the treatment of bloodstream infections caused by multidrug-resistant gram-negative bacteria.
• Skin and Soft Tissue Infections: Colistin can be employed for the treatment of serious skin and soft tissue infections caused by resistant gram-negative bacteria.

• Colistin is usually reserved as a last-line treatment option due to its potential side effects and the risk of developing resistance with prolonged use.

Forms of Colistin

• Colistin is available in different forms and formulations for various routes of administration. The specific form and formulation of colistin will depend on the intended use and the type of infection being treated.

Here are some common forms of colistin:

• Colistin Sulfate Powder for Injection: This is the most common form of colistin used for intravenous (IV) administration. It comes as a sterile powder that is reconstituted with a compatible diluent before administration.
• Colistin Sulfate Solution for Inhalation: Colistin can also be formulated as a solution for inhalation. This form is used for the treatment of respiratory tract infections, such as ventilator-associated pneumonia (VAP), caused by multidrug-resistant gram-negative bacteria.
• Colistin Sulfate Capsules or Tablets: In some cases, colistin is available in oral formulations, usually as capsules or tablets. However, oral colistin is less commonly used due to poor absorption and the availability of more effective alternatives for systemic infections.
• Colistin Sulfate Cream or Ointment: Colistin can be formulated into a topical cream or ointment for the treatment of localized skin and soft tissue infections caused by multidrug-resistant gram-negative bacteria. Topical colistin is typically used in combination with other antimicrobial agents.
• Colistimethate sodium: Colistimethate sodium is a prodrug; it is produced by the reaction of colistin with formaldehyde and sodium bisulfite, which leads to the addition of a sulfomethyl group to the primary amines of colistin. Colistimethate sodium is less toxic than colistin when administered parenterally.

• It's important to note that the availability of specific forms and formulations of colistin may vary depending on the country and the manufacturer.
• The appropriate form and route of administration will be determined by the healthcare professional based on the individual patient's condition and the type of infection being treated.

Administration and Dosage

• Colistin is available in various formulations for different routes of administration, including intravenous (IV), intramuscular (IM), and inhalation.
• The specific formulation and dosage will depend on the type and severity of the infection, as well as the patient's individual characteristics.
• It is important to follow the prescribed dosage and duration of treatment as directed by a healthcare professional.

Adverse Effects

Some common side effects of colistin include:

• Nephrotoxicity: Colistin can have an impact on kidney function, potentially leading to kidney damage. Regular monitoring of renal function is essential during treatment.
• Neurotoxicity: Neurological side effects, such as dizziness, confusion, and peripheral neuropathy, can occur with colistin use, particularly at higher doses.
• Respiratory Side Effects: Inhalation of colistin can sometimes cause bronchospasm or other respiratory symptoms.
• Gastrointestinal Disturbances: Nausea, vomiting, and diarrhea are possible gastrointestinal side effects of colistin.
• Allergic Reactions:In rare cases, individuals may experience allergic reactions to colistin, including skin rash, itching, or swelling. Severe allergic reactions, such as anaphylaxis, are rare but can occur.

• It is important to report any concerning side effects to a healthcare professional promptly.

Resistance and Precautions

• The emergence of colistin-resistant bacteria, although still relatively uncommon, is a concern in healthcare settings. Careful use of colistin and adherence to appropriate infection control measures are crucial to prevent the development and spread of resistance.
• olistin should be used with caution in individuals with pre-existing kidney disease or neurologic conditions. Close monitoring of kidney function and neurological status is essential during treatment.

See Also

• Antibiotics
• Gram-Negative Bacteria
• Multidrug-Resistant Infections
• Infection Control

• Dailymed label info on Colistin
• FDA Colistin

Colistin Resources
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