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Sickle Cell Disease and Hydroxyurea

What is sickle cell disease?

Sickle cell disease is a genetic disorder that affects the red blood cells. Normal red blood cells are donut shaped and travel through blood vessels easily. Sickle cell disease causes red blood cells to become stiff and crescent shaped (sickled). Sickled red blood cells are fragile and have a shorter life span than normal red blood cells. As the body cannot replace the red blood cells fast enough, a person with sickle cell disease has a reduced number of these cells (anemia). Red blood cells carry oxygen to all parts of the body. When the red blood cells “sickle”, they can clog blood vessels and cause pain and organ damage.

Typical treatments for sickle cell disease:

  • Regular check-ups with your primary care doctor and hematologist
  • Take penicillin two times a day (all infants 2 months - 5 years, patients with a history of sepsis [bacteria in the blood], or surgical spleen removal)
  • Routine immunizations (shots)
  • Drink plenty of water and liquids each day
  • Avoid extreme hot or cold temperatures
  • Get plenty of rest and limit stress (physical and emotional)
  • Seek prompt medical care for fever (101 degrees or greater)
  • Contact your physician for pain not controlled by home medications
  • Take folic acid each day
  • Take hydroxyurea each day
  • What is hydroxyurea?

    Hydroxyurea is a prescription medicine taken by mouth. In sickle cell disease, it is used to:

  • reduce the number and severity of painful events
  • prevent acute chest syndrome (sudden onset of difficult breathing)
  • reduce the need for blood transfusions
  • decrease hospitalizations

Studies show that taking hydroxyurea improves life expectancy and decreases the risk of organ damage in adults and children with sickle cell disease. Hydroxyurea may be useful to prevent other complications of sickle cell disease such as strokes. A recent study found that hydroxyurea is a safe sickle cell treatment for infants and children as young as 6-18 months of age. Starting a child with sickle cell disease on hydroxyurea as early as possible may improve his quality of life (NIH News, May 12, 2012).

How does hydroxyurea work?

Hydroxyurea helps the body make red blood cells with increased amounts of fetal hemoglobin (Hb F). Hb F is one type of hemoglobin we are born with which usually goes away during the first year of life. Hb F helps to keep hemoglobin from sickling.

Hydroxyurea also reduces the number of white blood cells and platelets. White blood cells and platelets are usually high in sickle cell disease. Too many white blood cells (WBCs) and platelets can cause damage to the blood vessels. Also, high WBCs and platelets are associated with more severe complications of sickle cell disease such as stroke and acute chest syndrome.

Hydroxyurea does not work right away. It can take several months for the hydroxyurea to start to work. It must be taken EVERY DAY.

Common side effects of hydroxyurea:

  • Lowers white blood cells (WBCs) - increased risk of infection if WBCs are too low
  • Lowers platelets - increased risk of bleeding if platelets are too low
  • Discolored nails
  • Weight gain or weight loss
  • Skin rash
  • Hair thinning
  • Nausea
  • Diarrhea or constipation

We will follow your child closely while on hydroxyurea to look for these side effects. Side effects can generally be reversed with dose changes. If you notice any of the above side effects or you are concerned about your child, contact the sickle cell office at 757-668-8260 or 757-668-7243.

Call your child’s doctor immediately if your child has an allergic reaction such as hives, itching, difficulty breathing, chest tightness, swelling of the face, lips, or tongue.

Other facts about hydroxyurea:

It is necessary to monitor blood counts regularly when taking hydroxyurea. Low blood counts are usually managed by lowering dose or stopping the medication for a few weeks.

In the past, there was concern about a possible cancer risk while taking hydroxyurea. Hydroxyurea has been used in patients with sickle cell disease for more than 20 years. There are no reports linking hydroxyurea as a cause of cancer in patients with sickle cell disease who used this medication. Sickle cell disease experts agree that hydroxyurea does NOT cause cancer.

Avoid pregnancy while taking hydroxyurea. This medicine may cause harm to an unborn baby if it is taken while pregnant. If you become pregnant, stop hydroxyurea immediately and contact your doctor’s office right away.


Disclaimer: This information is not intended to substitute or replace the professional medical advice you receive from your child's physician. The content provided on this page is for informational purposes only, and was not designed to diagnose or treat a health problem or disease. Please consult your child's physician with any questions or concerns you may have regarding a medical condition.

Reviewed: 10/2013