Tianyun Colistimethate Sodium for Injection

1. Indications and Usage
Serious Gram-Negative Infections: Treatment of acute or chronic infections caused by susceptible strains of Gram-negative bacteria.
Primary Pathogens: Efficacy has been demonstrated against Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli, and Klebsiella pneumoniae.
Usage Restriction: To reduce the emergence of resistant bacteria, it should be used only for confirmed or highly suspected sensitive bacterial infections.
2. Dosage and Administration
Route of Administration: For Intravenous (IV) or Intramuscular (IM) Administration ONLY.
Recommended Dosage:
Normal Renal Function: The total daily dose for adults and pediatric patients is 2.5 to 5 mg/kg (calculated as colistin base), divided into 2 to 4 doses. The maximum daily dose should not exceed 5 mg/kg.
Obese Patients: Dosing should be calculated based on ideal body weight.
Renal Impairment: Dosage adjustment is required for patients with renal dysfunction.
Critical Administration Instructions:
IV Injection: Administer half the daily dose over 3 to 5 minutes every 12 hours.
IV Infusion: Administer half the daily dose via IV injection, followed by the remaining half via slow IV infusion over 22 to 23 hours.
Preparation: Reconstitute with Sterile Water for Injection. Gently rotate to avoid foaming.
3. Mechanism of Action
Prodrug Conversion: Colistimethate sodium is a prodrug that is hydrolyzed in vivo to colistin methanesulfonate (CMS), which is then converted to the active moiety, colistin (polymyxin E).
Bactericidal Activity: Colistin selectively targets the outer membranes of Gram-negative aerobic bacteria by binding to lipopolysaccharides, displacing cations, and disrupting the cell membrane, ultimately leading to bacterial death.
4. Safety and Warnings
Nephrotoxicity: Dose-dependent nephrotoxicity may occur. Kidney function must be monitored closely, and the drug should be discontinued if renal toxicity manifests.
Neurotoxicity: Transient neurological abnormalities may occur, including perioral or extremity paresthesia, dizziness, vertigo, and confusion. In severe cases, neuromuscular blockade leading to respiratory arrest may occur.
Hypersensitivity: Contraindicated in patients with a history of hypersensitivity to colistimethate sodium or any component of the formulation.
5. Adverse Reactions and Clinical Research
Most Common Adverse Reactions: Nephrotoxicity, neurotoxicity (paresthesia, dizziness), gastrointestinal discomfort, skin rash, and elevated blood urea nitrogen (BUN) or creatinine.
Clinical Research Highlights: This formulation has been proven effective in treating severe infections caused by multidrug-resistant Gram-negative bacteria, serving as a critical salvage therapy in clinical practice.
6. Drug Interactions
Neuromuscular Blockers: Concomitant use with curare-like muscle relaxants or other drugs causing neuromuscular blockade may potentiate respiratory paralysis and neuromuscular blockade.
Other Nephrotoxic Agents: Concurrent use with other nephrotoxic antibiotics (e.g., aminoglycosides) may increase the risk of kidney damage.
7. Pharmaceutical Information
Chemical Composition: Active Ingredient: Colistimethate Sodium.
Appearance: White or off-white cake or powder.
Packaging: Single-use vial (150 mg calculated as polymyxin E).
Storage: Store according to specific regional guidelines, typically at room temperature or controlled room temperature.