Polymyxin B


C. diff Risk


Oral Bioavailability


Approximate Cost


Spectrum Of Activity


Loading Dose
20000 to 25000 IU/kg IV x 1

Maintenance Dose
250000 to 30000 IU/kg/day in 2 divided doses starting 12 hours after loading dose

No dose adjustment

No dose adjustment

Infectious Diseases consultation required

General Information

Acceptable Uses

  •  Infections due to MDR Enterobactericiae, Acinetobacter, and Pseudomonas on a case-by-case bass.

  •  Per UCLA Policy HS 1444, formal ID consultation is required for use of polymyxin B

Unacceptable Uses

  •  Infections due to non-MDR pathogens for which alternate therapy, particularly beta-lactam antibiotics, are available

  • Prophylaxis

Common Usage

Severe infectious caused by multidrug-resistant Gram-negative organisms when other antimicrobial options are limited

Drug Monitoring


  • BMP minimum of twice weekly


  • Monitor for nephrotoxicity, neurotoxicity, neuromuscular blockade.

Adverse Effects

  •  Nephrotoxicity

  •  Neurotoxicity

  •  Electrolyte abnormalities

Major Interactions

May enhance the effect of other neuromuscular blocking agents