• Type: Antibiotic
  • Dosage Forms: IV
  • Common Trade Names:

Adult Dosing

  • 2.5-5 mg/kg/day divided q6-12hr IV/IM; not to exceed 5 mg/kg/day

Pediatric Dosing

  • <12yo: safety/efficacy not established

Special Populations

  • Pregnancy Rating: C
  • Lactation: Unknown, use caution
  • Renal Dosing
    • CrCl 50-79 mL/min: 2.5-3.8 mg/kg/day IV/IM divided q12hr
    • CrCl 30-49 mL/min: 2.5 mg/kg/day IV/IM qDay or divided q12hr
    • CrCl 10-29 mL/min: 1.5 mg/kg IV/IM q36hr
  • Hepatic Dosing: Not established


  • Allergy to class/drug

Adverse Reactions


  • Anaphylaxis
  • Acute respiratory failure, particularly in myasthenia gravis or recent use of NMJ blockade
  • Nephrotoxicity
  • Neurotoxicity, seizures
  • C. diff pseudomembranous colitis


  • Dizziness
  • Paresthesias
  • Dysarthria


  • Half-life: 2-3h
  • Metabolism:
  • Excretion: Urine
  • Mechanism of Action: "Cationic detergent that damages bacterial cytoplasmic membrane, causing cell death"[1]

Antibiotic Sensitivities[2]

Group Organism Sensitivity
Gram Positive Strep. Group A, B, C, G R
Strep. Pneumoniae R
Viridans strep X1
Strep. anginosus gp X1
Enterococcus faecalis R
Enterococcus faecium R
Staph. Epidermidis R
C. jeikeium R
L. monocytogenes R
Gram Negatives N. gonorrhoeae R
N. meningitidis R
Moraxella catarrhalis X1
H. influenzae X1
E. coli S
Klebsiella sp S
E. coli/Klebsiella ESBL+ S
E coli/Klebsiella KPC+ S
Enterobacter sp, AmpC neg S
Enterobacter sp, AmpC pos S
Serratia sp X1
Serratia marcescens R
Salmonella sp X1
Shigella sp X1
Proteus mirabilis X1
Proteus vulgaris R
Providencia sp. X1
Morganella sp. X1
Citrobacter freundii X1
Citrobacter diversus X1
Citrobacter sp. X1
Aeromonas sp X1
Acinetobacter sp. S
Pseudomonas aeruginosa S
Burkholderia cepacia R
Stenotrophomonas maltophilia I
Yersinia enterocolitica X1
Francisella tularensis X1
Brucella sp. X1
Legionella sp. X1
Pasteurella multocida X1
Haemophilus ducreyi X1
Vibrio vulnificus X1
Misc Chlamydophila sp X1
Mycoplasm pneumoniae X1
Rickettsia sp X1
Mycobacterium avium X1
Anaerobes Actinomyces X1
Bacteroides fragilis X1
Prevotella melaninogenica X1
Clostridium difficile X1
Clostridium (not difficile) X1
Fusobacterium necrophorum X1
Peptostreptococcus sp. X1


  • S susceptible/sensitive (usually)
  • I intermediate (variably susceptible/resistant)
  • R resistant (or not effective clinically)
  • S+ synergistic with cell wall antibiotics
  • U sensitive for UTI only (non systemic infection)
  • X1 no data
  • X2 active in vitro, but not used clinically
  • X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
  • X4 active in vitro, but not clinically effective for strep pneumonia

See Also