$$ ($26-$100/day)

General Information

  • SCr/BUN, urine output

  • Neurotoxicity

  • Nephrotoxicity including acute renal failure

Neuromuscular-Blocking Agents: 

  • Colistimethate may enhance the neuromuscular-blocking effect of Neuromuscular-Blocking Agents
  • Management: If possible, avoid concomitant use of these products
    • Monitor for deeper, prolonged neuromuscular-blocking effects (respiratory paralysis) in patients receiving concomitant neuromuscular-blocking agents and colistimethate

Polymyxin preferred for systemic infections. Colistin preferred for infections of the lower urinary tract.

  • Distribution: CSF penetration: ~5%
  • Protein binding: 50%
  • Metabolism: Colistimethate sodium (inactive prodrug) is hydrolyzed to colistin (active form)
    • Note: Only ~30% of colistimethate sodium is converted to colistin
  • Half-life elimination: 2-3 hrs
  • Time to peak
    • 2 hours (range: 1 to 4 hours)
    • Critically ill: ~7 hrs
  • Excretion: Primarily urine (as unchanged drug)
    • Most colistin recovered in the urine is from postexcretion hydrolysis of colistimethate sodium