[Blood damage due to chloramphenicol and thiamphenicol]

Dose-related blood dyscrasias during treatment with either chloramphenicol or thiamphenicol chiefly include erythroid suppression and may be recognized at an early stage by observation of reticulocytopenia and an increased serum iron concentration. Ferrokinetic studies show the typical features of sideroblastic anemia. Whilst chloramphenicol is conjugated with glucuronic acid in the liver, thiamphenicol is predominantly eliminated by the kidney in its unmodified form. Sensitization against both drugs has been described and may, following reexposure, lead to dangerous granulocytopenia. Potentially the most dangerous late complication after chloramphenicol treatment, i.e. aplastic anemia, has not thus far been observed in patients treated with thiamphenicol.