Chloramphenicol

Snapshot

• A 33-year-old man presents to the emergency department for fever, headache, and rash. His symptoms are accompanied by myalgias and malaise and began approximately 3 days ago. He returned from a trip in North Carolina, where he believes he was bitten by a tick. He has no significant past medical history. He is severely allergic to penicillin and doxycycline. Physical examination is notable for a blanching erythematous rash with macules on the wrist and ankles. He is started on chloramphenicol. (Rocky Mountain spotted fever)

Introduction

• Mechanism of action 
  • reversibly binds to the 50S ribosomal subunits, blocking peptidyltransferase and impairing protein synthesis
    • bacteriostatic
      • prevents bacterial reproduction
• Mechanism of resistance
  • drug inactivation via a plasmid-encoded acetyltransferase
• Clinical use
  • meningitis
    • Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae
  • Rocky Mountain spotted fever
• Adverse events
  • aplastic anemia (dose independent) 
  • anemia (dose dependent)
  • gray baby syndrome 
    • seen in premature infants due to their lack of liver UDP-glucuronosyltransferase