Infectious Disease Compendium

Polymyxin B (Neosporin®)


Although the package insert says decrease dose of decreased gfr, there is higher mortality at lower doses.

CrCl Formula

1.5-2.5 mg/kg/d

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


Peritoneal dialysis:

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


''We put forth the view that overall polymyxin B has superior clinical pharmacological properties compared with CMS. colistin (PubMed)."

FYI there is an interesting literature on using polymyxin as a endotoxin binder for gram negative sepsis.

Treatment of choice

Use for

Bladder irrigation, blepharitis, conjunctivitis, conjunctivitis, corneal infection, gram-negative nosocomial infections, meningitis, oropharynx decontamination, pneumonia, sepsis, Serratia marcescens infections.

Don't use for