Patient selection: polycythemia vera following therapy with hydroxyurea
Parameters:
(1) hematocrit
(2) platelet count
(3) white blood cell (WBC) count
(4) splenomegaly
(5) absolute neutrophil count
(6) hemoglobin
(7) adverse side effects related to hydroxyurea therapy (leg ulcers, mucocutaneous lesions, fever, GI symptoms or pneumonia)
(8) dose and duration of hydroxyurea therapy
Hydroxyurea resistance or intolerance is defined as one or more of the following:
(1) presence of adverse effects due to the hydroxyurea therapy
(2) phlebotomy required to keep hematrocrit < 45% after 3 months of hydroxyurea therapy at a dose >= 2 g per day
(3) platelet count > 400,000 per µL AND WBC count > 10,000 per µL (uncontrolled myeloproliferation) after 3 months of hydroxyurea therapy at a dose >= 2 g per day
(4) failure to reduce massive splenomegaly by > 50% as measured by palpation after 3 months of hydroxyurea therapy at a dose >= 2 g per day
(5) failure to completely relieve symptoms related so splenomegaly after 3 months of hydroxyurea therapy at a dose >= 2 g per day
(6) absolute neutrophil count < 1,000 per µL at lowest dose of hydroxyurea required to achieve a complete or partial response
(7) platelet count < 100,000 per µL at lowest dose of hydroxyurea required to achieve a complete or partial response
(8) hemoglobin < 10 g/dL at lowest dose of hydroxyurea required to achieve a complete or partial response
