Colistin (Polymyxin E)
Brand names: Colomycin, Promixin (nebulised)
Colistin (polymyxin E) is a polymyxin antibiotic used as a last-line agent against multidrug-resistant Gram-negative organisms such as Pseudomonas, Acinetobacter and carbapenem-resistant Enterobacterales.
ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.
Clinical monograph
How it works
It binds the lipopolysaccharide and phospholipids of the Gram-negative outer membrane, displacing stabilising cations and disrupting the membrane to cause cell death.
Prescribing in practice
- Nephrotoxicity and neurotoxicity are dose-related and often dose-limiting, requiring renal-function-adjusted dosing and avoidance of concurrent nephrotoxic agents where feasible.
- It is used as a reserve antibiotic under specialist and microbiology guidance to limit emergence of resistance.
- Concurrent neuromuscular blockers or other agents impairing neuromuscular transmission should be used cautiously because of potential additive weakness.
Monitoring
Monitor renal function throughout therapy and watch for neurotoxic effects including paraesthesia, dizziness and muscle weakness.
Counselling the patient
- Report any numbness, tingling, dizziness or change in urine output.
- Treatment is given and supervised by the specialist team because it is reserved for resistant infections.
Evidence & guidelines
Use reflects established product information and microbiology guidance for resistant Gram-negative infection.
Reference: EUCAST Colistin Guidelines; PHE MDR Organism Guidelines; Daikos et al. (Colistin Combinations); MHRA SPC Colomycin; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.