Hydroxyurea Therapy

The benefits of hydroxyurea therapy in sickle cell anemia are extensive and well established, and were first demonstrated by the Multicenter Study of Hydroxyurea in Sickle Cell Anemia, a double blind, placebo controlled trial in 299 adults with sickle cell anemia. The clinical trial, which lasted for 21 months, showed that patients with sickle cell anemia treated with hydroxyurea had dramatically fewer painful episodes than those who received placebos. Firstly, among the 299 adults studied at 21 clinics, 152 patients that were administered hydroxyurea therapy had lower annual rates of crises than the 147 patients given placebo. Patients who were administered hydroxyurea had 2.5 crises per year compared to patients administered placebos with
Thirdly, the percentage of HbF cells increased from 35% to 70% within 10 months of hydroxyurea treatment compared to patients taking placebos who had HbF levels at 30% throughout the entire trial. Lastly, the neutrophil (white blood cells) were lower in patients taking hydroxyurea. Finally, in this trial of the effectiveness of hydroxyurea in patients with sickle cell anemia, treatment with hydroxyurea caused a 50% reduction in the median annual rate of painful crises. The mechanisms of hydroxyurea, to increase HbF and decrease neutrophils (white blood cells) showed to be directly correlated with the 50% reduction in annual pain crises. Not only did the results show a decrease in pain crises and its reoccurrence but it also showed that HbF levels doubled and neutrophil levels decreased after hydroxyurea therapy. Moreover, the reductions in pain crises and its reoccurrence as well as the increase in HbF and decrease in neutrophils (white blood cells) were only seen in patients taking hydroxyurea therapy and not patients taking