Bone Marrow Depression Induced by Chloramphenicol or Phenylbutazone

Abstract

With two registries for adverse drug reactions, a follow-up survey was made of 151 cases reported of bone marrow depression following use of chloramphenicol (124 patients), phenylbutazone (24), or both drugs (3). Leukemia subsequently developed in three patients with bone marrow depression attributed to use of chloramphenicol, but only one had characteristics suggesting a cause-and-effect relationship between drug exposure and leukemia. A review of clinical and epidemiologic information provides inadequate evidence that either drug is leukemogenic. Among other sequelae in the survey were four cases of hemolytic anemia; these four cases included two with paroxysmal nocturnal hemoglobinuria. Several problems arise in evaluating a causal association between drug exposure and diseases such as leukemia.