colistimethate sodium: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
colistimethate sodium: clinical details
Prescribing considerations
- Confirm organism identification, susceptibility, indication, route and product.
- Reserve systemic treatment for serious Gram-negative infection when commonly used antibacterials are ineffective or unsuitable.
- Supervise initial inhaled administration and assess bronchial hyperreactivity.
- Review renal impairment, dehydration, concurrent nephrotoxins or neurotoxins, myasthenia gravis, porphyria and significant haemoptysis.
- Avoid confusion between International Units, colistimethate sodium mass and colistin-base activity.
Contraindications and cautions
- Hypersensitivity to colistimethate sodium, colistin or related polymyxins, according to the selected product.
- Myasthenia gravis and porphyria require extreme caution but are not absolute contraindications in the selected product information.
Monitoring
- With systemic treatment, monitor renal function and assess neurological and neuromuscular toxicity.
- Consider serum electrolytes if pseudo-Bartter syndrome is suspected during intravenous treatment.
- With inhaled treatment, assess lung function before and after initial administration and periodically if bronchial hyperreactivity is a concern.
- During prolonged inhaled treatment, review sputum microbiology, susceptibility, response, adverse effects and continuing need.
- Consider systemic exposure assessment in inhaled patients with renal impairment or other toxicity risks.
Clinical pharmacology
Colistimethate sodium is an inactive prodrug that hydrolyses to colistin. Colistin is a concentration-dependent bactericidal polymyxin that disrupts the outer membranes of susceptible aerobic Gram-negative bacteria. Renal elimination and variable conversion affect systemic exposure.
Formulation and product differences
- Colobreathe is a dry-powder capsule used only with its Turbospin inhaler and is licensed for cystic fibrosis from six years of age.
- Promixin is a powder prepared as a nebuliser solution.
- Colomycin powder can be prepared for injection, infusion or inhalation; route-specific preparation and monitoring apply.
- Inhaler and nebuliser products are not directly interchangeable because their devices, preparation and delivered lung exposure differ.
colistimethate sodium preparations and strengths
Capsule
Route: Oral
Strengths: 1662500 units
colistimethate sodium interactions
Tell the prescriber about all treatments, including inhaled and hospital-administered medicines.
Aminoglycosides, such as gentamicin, amikacin or tobramycin
Combined treatment can increase kidney and nervous-system toxicity and requires careful monitoring.
Other nephrotoxic or neurotoxic medicines
Kidney or neurological toxicity may increase, particularly with systemic treatment.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.