Pharm 101: Chloramphenicol



  • Bacteriostatic
  • Inhibits protein synthesis:
    • Binds reversibly to 50S subunit of the bacterial ribosome
    • Inhibits peptide bone formation

  • IV administration of prodrug
  • Widely distributed to all tissues
    • CNS/CSF concentrations equal to serum
  • Metabolism to inactive metabolites by:
    • Conjugation with glucuronic acid (hepatic)
    • Reduction to inactive aryl amines
  • Renal excretion of active (10%) and inactive drug

Antimicrobial activity
  • Broad spectrum antibiotic active against both gram-positive and gram-negative organisms
    • H influenza, Neisseria are highly susceptible
  • Also active against rickettsiae
  • Does not treat chlamydiae
  • Clinical uses:
    • Rarely used
    • Rickettsial infections
    • Bacterial meningitis if penicillin allergic

Adverse effects
  • GI upset
  • Bone marrow suppression
    • Dose-related reversible suppression of RBC production
  • Gray baby syndrome (flaccidity and shock) in newborn infants
    • Lack effective glucuronic acid conjugation mechanism
    • Require dose reduction
  • CYP enzyme inhibitor
    • Half-life of phenytoin and warfarin prolonged

  • Caution in hepatic and renal insufficiency
  • Dose reduction in newborns and premature infants


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MBBS (UWA) CCPU Emergency Medicine Trainee with interests in medical education, ECG interpretation, and the use of point-of-care ultrasound in the undifferentiated patient. Co-author of the LITFL ECG Library | Twitter

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