Hydroxyurea-Induced Thrombocytopenia in Myeloproliferative Disorders

Mechanism and Evidence

• The European LeukemiaNet and NCCN guidelines specifically identify thrombocytopenia as a recognized adverse effect of hydroxyurea therapy, which is a cytoreductive agent that causes bone marrow suppression, affecting all cell lines including platelets 1, 2
• Platelet counts <100 x 10^9/L at the lowest dose of hydroxyurea required to achieve clinical response is considered a criterion for hydroxyurea intolerance in polycythemia vera, according to the European LeukemiaNet and NCCN guidelines 1, 2, 3

Clinical Significance

• In patients with myeloproliferative disorders, the development of thrombocytopenia (platelet count <100 x 10^9/L) is considered a criterion for intolerance to hydroxyurea and may necessitate dose reduction or discontinuation, as recommended by the European LeukemiaNet and NCCN guidelines 1, 2

Management of Hydroxyurea-Induced Thrombocytopenia

• If platelet count falls below 100 x 10^9/L, consider dose reduction or temporary discontinuation of hydroxyurea, as recommended by the European LeukemiaNet and NCCN guidelines 1, 2
• For patients with persistent thrombocytopenia despite dose adjustments, consider alternative cytoreductive agents, such as interferon-alpha for polycythemia vera, as recommended by the European LeukemiaNet and NCCN guidelines 1, 4