What is hydroxyurea used for?

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From the Guidelines

Hydroxyurea is primarily used to treat sickle cell disease by increasing fetal hemoglobin production, which prevents red blood cells from sickling and reduces painful crises. The medication has been shown to decrease vaso-occlusive complications, including episodes of painful events and acute chest syndrome, hospitalizations, and need for transfusion 1. For adults with sickle cell disease, the typical starting dose is 15-20 mg/kg/day taken orally, with adjustments based on blood counts and response. Hydroxyurea use has a positive impact on health-related quality of life in people with HbSS or Sb0-thalassemia 1.

  • Key benefits of hydroxyurea include:
    • Reduction in painful crises
    • Decrease in hospitalizations
    • Reduction in need for transfusions
    • Improvement in health-related quality of life
  • Common side effects include:
    • Bone marrow suppression (lowered blood counts)
    • Gastrointestinal symptoms
    • Skin changes Regular blood monitoring is essential during treatment to check for toxicity, with a CBC and reticulocyte count monitored every 1 to 3 months depending on how long the child has been taking the medication and whether the child has attained a stable dose 1. The 2014 National Heart, Lung, and Blood Institute guidelines for SCD recommend offering hydroxyurea to every child with HbSS or Sb0-thalassemia at 9 months of age even without clinical symptoms 1. More recent guidelines, such as the American Society of Hematology 2019 guidelines, support the use of hydroxyurea in combination with erythropoiesis-stimulating agents for patients with SCD and chronic kidney disease, despite the very low certainty evidence for a net health benefit 1.

From the FDA Drug Label

Hydroxyurea capsules are indicated for the treatment of: • Resistant chronic myeloid leukemia. • Locally advanced squamous cell carcinomas of the head and neck (excluding the lip) in combination with chemoradiation.

Hydroxyurea is used for the treatment of resistant chronic myeloid leukemia and locally advanced squamous cell carcinomas of the head and neck (in combination with chemoradiation) 2. The main uses of hydroxyurea are:

  • Resistant chronic myeloid leukemia
  • Locally advanced squamous cell carcinomas of the head and neck (excluding the lip) in combination with chemoradiation 2 2

From the Research

Uses of Hydroxyurea

  • Hydroxyurea is used to reduce the frequency of painful episodes in sickle cell disease by increasing the level of HbF and haemoglobin level 3
  • It is also used to decrease the rate of acute chest syndrome (ACS) episodes and blood transfusions in adults with sickle cell disease 3
  • Hydroxyurea is employed as a cancer chemotherapeutic agent, specifically in the treatment of myeloproliferative disorders, such as polycythemia vera, essential thrombocythemia, and primary myelofibrosis 4
  • It is used in combination therapy for the management of malignant melanoma, head and neck cancers, and brain tumors 4
  • Hydroxyurea has been used to treat children with sickle cell disease, offering promise for ameliorating the clinical course of the disease 5
  • It is the only approved drug for the treatment of adults with sickle cell disease, reducing the frequency of painful crises and hospital admissions 6
  • Hydroxyurea may be useful in treating mediator symptoms in mast cell activation syndrome (MCAS), including previously refractory soft tissue and/or bone pain 7

Conditions Treated with Hydroxyurea

  • Sickle cell disease
  • Myeloproliferative disorders (e.g. polycythemia vera, essential thrombocythemia, primary myelofibrosis)
  • Malignant melanoma
  • Head and neck cancers
  • Brain tumors
  • Mast cell activation syndrome (MCAS)

Administration and Side Effects

  • Hydroxyurea can be administered orally, with minimal clinical toxicity 4
  • Common side effects include neutropenia, bone marrow suppression, elevation of hepatic enzymes, anorexia, nausea, vomiting, and infertility 3
  • Gastrointestinal disturbance and bone marrow depression are also reported as limitations of hydroxyurea therapy 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Hydroxyurea in sickle cell disease: drug review.

Indian journal of hematology & blood transfusion : an official journal of Indian Society of Hematology and Blood Transfusion, 2014

Research

Hydroxyurea: a key player in cancer chemotherapy.

Expert review of anticancer therapy, 2012

Research

Hydroxyurea for children with sickle cell disease.

Pediatric clinics of North America, 2008

Research

Utility of hydroxyurea in mast cell activation syndrome.

Experimental hematology & oncology, 2013

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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