Although the package insert says decrease dose of decreased gfr, there is higher mortality at lower doses.
IV: 15,000-25,000 units/kg/day divided q12 hr; not to exceed 25,000 units/kg/day
IM: 25,000-30,000 units/kg/day divided q4-6hr
Intrathecal: 50,000 daily for 3-4 days; then qd or qod for at least 2 weeks
Total daily dose not to exceed 2,000,000 units/day
CrCl >20: 75-100% usual dose/day divided q12hr
CrCl 5-20: 50% usual dose/day divided q12hr
CrCl <5: 15% usual dose/day q12hr
Important side effects
Nephrotoxicity (may be less toxic than colistin), neurologic (irritability, weakness, ataxia, drowsiness, extremity numbness, blurred vision), neuromuscular blockade; respiratory depression or paralysis, pain (severe) at im injection site.
Important drug interactions
Nondepolarizing neuromuscular blockers.
Rants and Screeds
FYI there is an interesting literature on using polymyxin as a endotoxin binder for gram negative sepsis.
Treatment of choice
Bladder irrigation, blepharitis, conjunctivitis, conjunctivitis, corneal infection, gram-negative nosocomial infections, meningitis, oropharynx decontamination, pneumonia, sepsis, Serratia marcescens infections.