ABSTRACT
Aplastic anemia is a disorder characterized by pancytopenia in the presence of significant marrow hypoplasia or aplasia. Congenital aplastic anemias are typically associated with dysmorphic physical features, such as growth retardation, limb hypoplasia, and cardiac or renal abnormalities. Shwachman-Diamond syndrome is associated with pancreatic insufficiency. Aplastic anemia is much more rare, occurring in 1 of 10,000 administrations. It is more frequent following oral administration of the drug. This has suggested that chloramphenicol metabolites produced by intestinal bacteria are predominantly responsible for marrow aplasia. Aplastic anemia is observed with a variety of other classes of antibiotics as well. Individuals exposed to acute high-dose whole-body irradiation typically develop marrow aplasia at 3–6 weeks. The association between industrial hydrocarbons such as benzene and pancytopenia or aplastic anemia is well established. The toxic effects of benzene are associated with its concentration in marrow fat and are attributed to metabolites, particularly hydroxyquinone phenols.
