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Multi-Drug Resistant (MDR) Pseudomonas, Acinetobacter, and Enterobacterales infections.
Polymyxin B is preferred over colistin for all MDR-GNB systemic infections outside of the urinary tract due to more predictable pharmacokinetics.
Colistin is preferred for urinary tract infections, nebulization administration, and intrathecal/intraventricular administration.
For treatment of MDR-GNB respiratory tract infections, administered as nebulization as 150mg inhaled q12hr.
Laboratory:
Clinical:
Antimicrobial class: Polymyxin
Pregnancy category: C
Average serum half life: 2-3 hours for Colistimethate sodium (CMS): prodrug and >4 hours for colistin (extended with renal impairment)
Lung penetration: Poor
Urine penetration: Therapeutic
CSF penetration: Poor