Chloramphenicol is primarily bacteriostatic. It binds to the 50S subunit of the ribosome, thereby inhibiting bacterial protein synthesis.
Chloramphenicol is well absorbed orally. Parenteral therapy should be IV.
Chloramphenicol is distributed widely in body fluids, including CSF, and is excreted in urine. Because of hepatic metabolism, active chloramphenicol does not accumulate when renal insufficiency is present.
Chloramphenicol has a wide spectrum of activity against
Because of bone marrow toxicity, the availability of alternative antibiotics, and the emergence of resistance, chloramphenicol is no longer a drug of choice for any infection, except for
However, when chloramphenicol has been used to treat meningitis caused by relatively penicillin-resistant pneumococci, outcomes have been discouraging, probably because chloramphenicol has poor bactericidal activity against these strains.
Chloramphenicol is contraindicated if another drug can be used instead.
Use During Pregnancy and Breastfeeding
Use of chloramphenicol during pregnancy results in fetal drug levels almost as high as maternal levels. Gray baby syndrome is a theoretical concern, particularly near term, but there is no clear evidence of fetal risk.
Chloramphenicol enters breast milk. Safety during breastfeeding has not been determined.
Adverse effects include
There are 2 types of bone marrow depression:
Hypersensitivity reactions are uncommon. Optic and peripheral neuritis may occur with prolonged use.
The neonatal gray baby syndrome, which involves hypothermia, cyanosis, flaccidity, and circulatory collapse, is often fatal. The cause is high blood levels, which occur because the immature liver cannot metabolize and excrete chloramphenicol. To avoid the syndrome, clinicians should not give infants ≤ 1 mo > 25 mg/kg/day initially, and doses should be adjusted based on blood levels of the drug.
Last full review/revision July 2009 by Matthew E. Levison, MD