Kolistimetatnatrium Noridem (Colistimethate Sodium)

Kolistimetatnatrium Noridem is a polymyxin antibiotic used to manage Gram‑negative respiratory infections, especially in patients with chronic lung disease.

• Respiratory infections (Gram‑negative): Reduces bacterial load in the airways, improving pulmonary function.
• Cystic fibrosis with Pseudomonas aeruginosa: Controls chronic lung infection and helps preserve lung function.
• Bronchiectasis with chronic Pseudomonas infection: Decreases exacerbation frequency and bacterial colonisation.

• Colistimethate Sodium binds to the lipopolysaccharide layer of the outer membrane of Gram‑negative bacteria, displacing calcium and magnesium ions. This interaction disrupts membrane integrity, increases permeability, and leads to leakage of cellular contents, ultimately causing bacterial cell death.

Adverse reactions may occur with inhaled colistimethate sodium, ranging from mild to serious.

Common Side Effects

• Cough: irritation of the airway during inhalation.
• Bronchospasm: transient narrowing of the bronchi.
• Throat irritation: discomfort or soreness in the throat.
• Taste disturbance: altered taste perception.
• Nausea: mild gastrointestinal upset.
• Headache: mild to moderate headache.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Respiratory distress: worsening breathing difficulty.
• Hemoptysis: coughing up blood.
• Renal toxicity: impaired kidney function due to systemic absorption.
• Neurotoxicity: rare peripheral neuropathy or dizziness.
• Severe bronchospasm: prolonged airway constriction.

When prescribing inhaled colistimethate sodium, clinicians should consider several safety measures.

• Renal function: Monitor serum creatinine and urine output due to potential systemic absorption.
• Hepatic function: Assess liver enzymes periodically.
• Pregnancy: Use only if the potential benefit justifies the potential risk to the fetus.
• Bronchospasm risk: Observe patients for wheezing during and after administration.
• Drug resistance: Reserve for infections confirmed to be susceptible to colistin.
• Store at 2-8°C: Keep refrigerated, protect from light, do not freeze.

Colistimethate sodium may interact with other medications, affecting safety or efficacy.

Major Interactions (Avoid)

• Aminoglycosides: Increased risk of nephrotoxicity when combined.
• Neuromuscular blocking agents: Enhanced neuromuscular blockade, leading to respiratory paralysis.
• Other polymyxins: Additive toxicity, especially renal.

Moderate Interactions (Monitor Closely)

• Loop diuretics: May potentiate renal impairment.
• Corticosteroids: May mask signs of infection, requiring careful monitoring.
• Bronchodilators: May reduce bronchospasm risk, but dosing adjustments may be needed.