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.