Hydroxyurea in the treatment of polycythemia vera: a prospective study of 100 patients over a 20-year period.

From 1963 to 1983, I treated 100 patients with polycythemia vera, using phlebotomy and the adjunctive agent hydroxyurea. These 78 male and 22 female patients ranged in age from 24 to 88 years (mean 55.7). Duration of therapy ranged from three to 216 months (mean 64.9). The mean daily dose was 0.72 gm, and the median dose was 0.64 gm. Hydroxyurea gave adequate control of red cells, platelets, and spleen size. Cytopenia was not observed. Phlebotomy requirements were markedly reduced. Leukocyte alkaline phosphatase scores were generally lowered and several blood chemistry values returned to normal. Side effects were minimal, and there were no drug-related deaths. Infections were not a problem. Hydroxyurea, a metabolic inhibitor of desoxyribonucleic acid, does not interfere with the synthesis of ribonucleic acid or protein and is thus probably less leukemogenic than radioactive phosphorus and alkylating agents. Acute myelogenous leukemia was seen in one patient after five years of continuous hydroxyurea therapy. He had received no other myelosuppressant agent. Because hydroxyurea is safe and effective in the treatment of polycythemia vera, it should be considered as first-line therapy. It probably offers practical and theoretic advantages over present therapy particularly when the disease is not well controlled by phlebotomy alone.