Colisma^®

Colisma®

Generic Name: Colistimethate Sodium
Dosage Form: Lyophilized powder containing 1 million and 4.5 million units for preparing an injectable solution
Drug Class: Antibiotic

Colistimethate Overview:

Colistimethate (Colistimethate Sodium, Colistin, or Polymyxin E) is an inactive prodrug that is converted to colistin in the body. Colistin damages the bacterial cytoplasmic membrane, causing leakage of intracellular contents and ultimately killing the pathogen.

Indications for Colistimethate Use:

• Treatment of acute and chronic infections caused by certain sensitive Gram-negative microorganisms, such as Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli, and Klebsiella pneumoniae, which are resistant to other antibiotics, or in patients who cannot use other antibiotics.
• Cystic fibrosis.
• Prevention of exacerbations in bronchiectasis.

Dosage Form of Colistimethate:

Lyophilized powder containing 1 million and 4.5 million units of Colistimethate Sodium for preparing an injectable solution.

Preparation of Colistimethate:

• Colistimethate 1 million units: Add 1 mL of sterile water for injection to the vial and shake gently until the powder is completely dissolved. The resulting solution contains 34 mg/mL of Colistimethate Sodium.
• Colistimethate 4.5 million units: Add 2 mL of sterile water for injection to the vial and shake gently until the powder is completely dissolved. The resulting solution contains 75 mg/mL of Colistimethate Sodium.
• After adding the water for injection, gently rotate the vial to avoid foam formation. The solution should be checked for particles or color change before use.
• If there are particles or a color change, do not use the solution.
• If dilution is required, Colistimethate is compatible with the following solutions:
• 0.9% Sodium Chloride
• 5% Dextrose
• 5% Dextrose and 0.9% Sodium Chloride
• 5% Dextrose and 0.45% Sodium Chloride
• 5% Dextrose and 0.225% Sodium Chloride
• Ringer's Lactate

How to Administer Colistimethate:

Colistimethate can be administered intravenously or intramuscularly (in large muscles such as the gluteal or lateral thigh muscles).

Intravenous Injection:

• Direct Injection: Administer half of the daily dose over 3-5 minutes every 12 hours.
• Direct Injection and Infusion: Administer half of the daily dose over 3-5 minutes, followed by the remaining dose over 1-2 hours as a slow infusion (over 22-23 hours or longer), after diluting with compatible solutions.

Monitoring During Colistimethate Treatment:

• Colistin blood levels.
• Serum creatinine and urea levels.
• Urine output.
• Signs of neurotoxicity.

Contraindications for Colistimethate:

• Hypersensitivity to Colistimethate, Colistin, or any component of the formulation.

Warnings and Precautions for Colistimethate:

• The use of Colistimethate can cause nephrotoxicity depending on the dose. The drug should be used with caution in patients with kidney failure, and the dosage should be adjusted based on the degree of renal impairment and the patient's age.
• Symptoms like tingling or numbness around the mouth, hands, and feet, itching, dizziness, and speech disturbances may occur. Reducing the dose typically improves these symptoms. If such symptoms occur, avoid tasks requiring high levels of alertness, such as driving or operating heavy machinery.
• Long-term use of Colistimethate can increase the risk of Clostridium difficile-associated diarrhea. If symptoms such as abdominal pain, very loose or watery stools, or bloody stools occur, contact a doctor immediately.

Colistimethate Use During Pregnancy and Breastfeeding:

• Before using Colistimethate during pregnancy or breastfeeding, consult your doctor.
• Colistin (the active form of Colistimethate Sodium) is excreted in breast milk, so breastfeeding should be done cautiously under medical supervision.

Side Effects of Colistimethate:

As with any medication, Colistimethate may cause some side effects, although not all individuals will experience them. Common side effects include:

• Decreased urine output.
• Dizziness.
• Fever.
• Rash, hives, and itching.

Drug Interactions with Colistimethate:

• Consult with your doctor or pharmacist before using Colistimethate with any other medications or supplements.

Packaging of Colistimethate:

• Each 1-million-unit package contains 10 vials of Colistimethate.
• Each 4.5-million-unit package contains 10 vials of Colistimethate.

Storage Conditions for Colistimethate:

• Store the drug at temperatures below 30°C, away from light and moisture.
• The drug is usable until the expiration date specified on the packaging. Do not use or store expired medications.
• Keep the medication out of the reach of children.
• Store the drug in its original packaging until use.

References:

1. Colistin (Colistimethate): Drug information, UpToDate 2025
2. Medicines.org.uk - Product Information