Chloramphenicol - Antibiotics Class Overview


– 50S ribosomal inhibitor.   IV or PO (but PO form unavailable in U.S.)
Spectrum: Broad spectrum vs Gram positives (including MRSA, E.faecium/VRE); Gram negatives but NOT Pseudomonas; Anaerobes, and unusual pathogens including spirochetes, Rickettsia, Erhlichia, Coxiella, Typhoid/Paratyphoid Salmonella.
Used for: Limited use in the U.S. due to potential toxicity (see below) – mainly for bacterial meningitis in patients with severe beta-lactam allergy (has activity vs S.pneumo, N.meningitidis, and H.influenza).  Used more widely in developing countries where benefit often outweighs risk.

 - A typical regimen in patients with bacterial meningitis and severe beta-lactam allergy would be Vancomycin + Chloramphenicol +/- Bactrim (for Listeria in the appropriate patients)
 - Toxicity: 1. Bone marrow suppression – direct, dose-related effect that is reversible. 2. Aplastic anemia – rare, idiosyncratic reaction (occurs at rate of 1/40,000), but generally fatal event.  Usually occurs several weeks after drug is stopped.  3. Gray baby syndrome in infants – presents with hypotension, shock, and cyanosis.

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