• Type: bacteriostatic antibiotic
  • Dosage Forms: IV, IM, eye drops
  • Common Trade Names: pentamycetin, chloromycetin

Adult Dosing

Infection, General

  • 50-100mg/kg/day IV divided q6h

Bacterial meningitis

  • 4 g/day IV divided q6h
  • Alt: 75-100mg/kg/day IV divided qgh

Bacterial conjunctivitis

  • 0.5% ophthalmic solution 1 drop QID for 7 days

Pediatric Dosing

Bacterial meningitis

  • 75-100mg/kg/day IV divided q6h; Max 4g/day

Special Populations

  • Pregnancy: Category C (risk not ruled out)
  • Lactation: passes into breast milk and should be avoided if possible
  • Renal Dosing: minimally excreted via kidneys
    • Adult: amount not defined
    • Pediatric: amount not defined
  • Hepatic Dosing: metabolized by the liver, therefore dose must be reduced
    • Adult: amount not defined
    • Pediatric: amount not defined


  • Allergy to class/drug

Adverse Reactions



  • headache
  • nausea, vomiting
  • diarrhea
  • fever
  • rash
  • urticaria
  • peripheral neuropathy
  • blurred vision


  • Half-life: 1.5 - 4.1 hours
  • Metabolism: Liver
  • Excretion: Urine
  • Mechanism of Action: binds to 50S ribosomal subunit inhibiting protein synthesis

Antibiotic Sensitivities[1]

Group Organism Sensitivity
Gram Positive Strep. Group A, B, C, G S
Strep. Pneumoniae S
Viridans strep X1
Strep. anginosus gp X1
Enterococcus faecalis I
Enterococcus faecium I
Staph. Epidermidis R
C. jeikeium R
L. monocytogenes S
Gram Negatives N. gonorrhoeae S
N. meningitidis S
Moraxella catarrhalis S
H. influenzae S
E. coli S
Klebsiella sp I
E. coli/Klebsiella ESBL+ I
E coli/Klebsiella KPC+ R
Enterobacter sp, AmpC neg R
Enterobacter sp, AmpC pos R
Serratia sp X1
Serratia marcescens R
Salmonella sp S
Shigella sp S
Proteus mirabilis X1
Proteus vulgaris I
Providencia sp. X1
Morganella sp. X1
Citrobacter freundii X1
Citrobacter diversus X1
Citrobacter sp. X1
Aeromonas sp X1
Acinetobacter sp. R
Pseudomonas aeruginosa R
Burkholderia cepacia S
Stenotrophomonas maltophilia S
Yersinia enterocolitica S
Francisella tularensis S
Brucella sp. S
Legionella sp. X1
Pasteurella multocida X1
Haemophilus ducreyi X2
Vibrio vulnificus X2
Misc Chlamydophila sp S
Mycoplasm pneumoniae S
Rickettsia sp S
Mycobacterium avium X1
Anaerobes Actinomyces X2
Bacteroides fragilis X2
Prevotella melaninogenica S
Clostridium difficile I
Clostridium (not difficile) S
Fusobacterium necrophorum S
Peptostreptococcus sp. S


  • 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


  1. Sanford Guide to Antimicrobial Therapy 2014