From the Guidelines
The normal starting dose of Hydroxyurea (Hydrea) for polycythemia vera is typically 500 mg daily, which can be gradually increased based on blood count response and tolerance, with a target dose of at least 2 g/d as indicated by the NCCN guidelines 1.
Key Considerations
- The dose should be adjusted every 2-4 weeks to achieve target blood counts, particularly a hematocrit below 45% and platelet count below 400,000/μL, while avoiding excessive myelosuppression.
- Patients should have regular blood count monitoring, initially every 1-2 weeks until stable, then every 1-3 months.
- Hydroxyurea works by inhibiting DNA synthesis in rapidly dividing cells, effectively reducing red blood cell, white blood cell, and platelet production in the bone marrow.
Important Side Effects
- Common side effects include cytopenias, gastrointestinal symptoms, skin changes, and oral ulcers.
- Patients should be advised to take the medication with food if stomach upset occurs and to report any unusual bleeding, fever, or signs of infection promptly.
Guidance from Recent Studies
- The NCCN guidelines 1 provide guidance on the management of polycythemia vera, including the use of hydroxyurea, and emphasize the importance of regular monitoring and dose adjustments to minimize toxicity and maximize efficacy.
- The European LeukemiaNet definition of resistance/intolerance to hydroxyurea 1 also provides useful guidance on the management of patients with polycythemia vera, although the more recent NCCN guidelines 1 take precedence in terms of recommendations for initial dosing and management.
From the Research
Normal Starting Dose of Hydroxyurea for Polycythemia Vera
- The normal starting dose of Hydroxyurea (Hydrea) for Polycythemia Vera is not consistently defined across all studies, but some studies provide guidance on the initial dosing.
- According to the study 2, the loading dose of Hydroxyurea was 30 mg/kg/day for 1 week, which was then reduced to 15 mg/kg/day. However, due to toxicity, it is recommended to administer Hydroxyurea initially at a dose of 15-20 mg/kg/day.
- The study 3 reports a mean daily dose of 0.72 gm, with a median dose of 0.64 gm, but does not specify the starting dose.
- The study 4 mentions an average dose of 1 g/day, which was sufficient to control hematocrit value and platelet count in the majority of patients.
- The study 5 does not provide information on the starting dose of Hydroxyurea.
- The study 6 reports that the most common maximum daily Hydroxyurea doses were 1000 mg (30.6%) and 500 mg (30.1%), with only 6.4% of patients receiving ≥ 2 g/d Hydroxyurea, but this refers to the maximum daily dose rather than the starting dose.
Key Findings
- The studies suggest that the starting dose of Hydroxyurea for Polycythemia Vera may vary, but a common approach is to start with a dose of 15-20 mg/kg/day or around 500-1000 mg/day.
- The dose may need to be adjusted based on the patient's response and tolerance to the medication, as reported in the studies 2, 5, and 6.