Bone-Marrow Depression Resulting from the Administration of Methicillin

DEPRESSION of bone marrow leading to aplastic anemia or pancytopenia is frequently observed after the administration of a wide variety of drugs. This serious toxic effect must be watched for in the evaluation of new drugs. The appearance of profound neutropenia with a markedly elevated concentration of serum iron in a patient receiving methicillin (2,6-dimethoxyphenyl penicillin )‡ suggested that this drug was most probably responsible for the hematologic disorder. When the drug was discontinued there was an immediate rise of neutrophils in the peripheral blood and a decrease in the concentration of serum iron. Although full-blown aplastic anemia did not . . .