RESUMO
The clinical symptoms, frequency and relation to intensity of treatment, and the course of the anemia produced by diasone are described. It is shown that the changes in the blood picture are limited to the red blood count, without disturbance of other components. The anemia begins early in the first weeks of treatment and as a general rule abates with complete recovery during the periods of rest from the drug. Investigations made in the treated patients have included the reticulocytosis, urobilinuria, bilirubinemia, and red blood cell resistance; the results of biopsy of the bone marrow in certain cases are also given. The findings show that the anemia is not due to a toxic action of the drug on the bone marrow, since there is good reticulocyte response in all cases and no leucopenia; furthermore, bone marrow biopsy shows a normal or increased erythroblastic activity, and granulopoiesis is also normal or increased. It is, therefore, deduced that the drug acts as a hemolytic toxin, as shown by the decrease in the red-blood-cell resistance, the presence of urobilin in the urine of almost all the cases, the absence of bile pigments in the urine, of direct bilirubin in the blood, and the absence of indirect bilirubinemia in the great majority of cases. Taking these facts into account adequate therapeutic measures, based on clinical experience, are suggested.