Polymyxin antibiotic
Colistimethate sodium
Brand names: Promixin, Colomycin, Colobreathe
Adult dose
Dose: Nebulised (Pseudomonas in CF): 1–2 million units BD. IV: loading 9 million units, then 4.5 million units BD
Route: IV/Nebulised/Inhaled DPI
Frequency: BD
Dose adjustments
Renal
Reduce IV dose in renal impairment per BNF
Clinical pearls
- Multi-drug-resistant gram-negative infections; nebulised long-term in CF P. aeruginosa
- Reserve antibiotic — narrow therapeutic window
Contraindications
- Myasthenia gravis
Side effects
- Nephrotoxicity
- Neurotoxicity (paraesthesia, vertigo, ataxia)
- Bronchospasm (inhaled)
Interactions
- Other nephrotoxins (aminoglycosides)
- Neuromuscular blockers
Monitoring
- U&E
- Neurological exam
Reference: BNF; https://bnf.nice.org.uk/drugs/colistimethate-sodium/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Infective Endocarditis · ESC 2023 Infective Endocarditis Guidelines; NICE NG41
- Eczema Herpeticum · BAD; NICE CKS
- Suspected Bacterial Meningitis (Adult) · NICE NG240 (2024); NICE NG143 (paeds)
- Clostridioides difficile Colitis · NICE NG199 (2021); IDSA/SHEA 2021
- Returning Traveller — Fever · NaTHNaC; PHE; ESCMID 2018
- Malaria — Diagnosis & Management · PHE 2016; WHO 2023