RESUMEN
Background Dipyrone is a non-narcotic analgesic/antipyretic widely used in some countries but prohibited in others due to suspected risk of agranulocytosis. The primary goal of this study was to evaluate hematological alterations in healthy adult volunteers after treatment with dipyrone. Methods The study enrolled 30 healthy volunteers of both genders, aged 19-37 years. They received tablets containing 500 mg of dipyrone sodium to be used four times daily for 7 consecutive days. Before the first administration, arterial pressure was measured and blood was collected in order to evaluate hematological baseline parameters. On the 8th day after the beginning of treatment, the volunteers had their blood pressure assessed once more and underwent a second blood draw. Total and specific leukocyte counts, creatinine, urea, aspartate aminotransferase (AST), alanine aminotransferase (ALT), erythrocytes, and platelets were quantitatively determined. Results No statistically significant difference was observed among total or specific leukocyte counts. Number of platelets, erythrocytes, hemoglobin, and hematocrit decreased after treatment. Diastolic pressure, mean arterial pressure (MAP), and urea concentration declined, while creatinine, AST, and ALT showed no significant alterations. It is noteworthy that, even for parameters that showed statistically significant changes, the highest and lowest values remained within the normal ranges. Conclusions Although dipyrone has historically been associated with agranulocytosis, leukocyte counts remained practically unchanged after oral administration of dipyrone. On the other hand, the present study adds evidence that dipyrone is able to produce statistically relevant decrease in number of platelets, erythrocytes, hemoglobin, and hematocrit in healthy adults, even after short-term treatment.