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Hydroxyurea for People With Sickle Cell Disease

Medically reviewed by: Corinna L. Schultz, MD

What Is Hydroxyurea?

Hydroxyurea is a medicine that can help people who have sickle cell disease. It keeps blood cells round and flexible, so they flow better and deliver oxygen to the body more easily. This means less pain and fewer trips to the hospital.

What Happens in Sickle Cell Disease?

Healthy red blood cells are soft, flexible, and round. Sickle cell disease makes red blood cells become sticky, hard, and C-shaped. The sickle cells get stuck and block the blood flowing inside small blood vessels. This can be painful and lead to other problems that need to be treated in a hospital.

Sickle cells also break down more quickly than healthy red blood cells. Not having enough red blood cells can lead to anemia. People with anemia feel tired and have less energy.

View Inside a Blood Vessel

How Does Hydroxyurea Help People With Sickle Cell Disease?

Hydroxyurea (pronounced: hy-drok-see-yer-EE-uh) helps the body make a type of hemoglobin that helps keep red blood cells round. Hemoglobin is the protein inside red blood cells that carries oxygen to the body. Round and flexible red blood cells work better and last longer. So people who take hydroxyurea can have more energy, and less pain and anemia. They often spend less time in the hospital.

Who Can Take Hydroxyurea?

Each person with sickle cell disease has their own experience. Hydroxyurea can help people who have:

  • some types of sickle cell disease (like the most common type, called hemoglobin SS)
  • lots of pain crises (some people get these often, but others don’t)
  • acute chest syndrome
  • severe anemia needing blood transfusions
  • tiny blockages without any pain. Sickle cells can scrape the inside of blood vessels. This creates small places for blood cells to get stuck and create a blockage. A blockage that stays small might not cause pain. But it can still prevent blood and oxygen from getting where they need to go.

You may have heard about hydroxyurea being used to treat other kinds of health problems, not just sickle cell disease. Like many medicines, hydroxyurea has different uses. In very high doses, it can help with some kinds of blood cancers. The dose used to treat sickle cell disease is very low.

What's It Like to Take Hydroxyurea?

Here are the basics of taking hydroxyurea:

  • type of medicine: It’s a liquid medicine or a small capsule.
  • dose: You swallow it one time each day.
  • time: You take it at the same time every day. (Some people like to set a reminder on their phone.)
  • blood tests: You get one before you start the medicine. Then you get them once per month.
  • changing the dose: If hydroxyurea affects blood cells beyond the red blood cells, the doctor can change the dose or stop the medicine.
  • in a few months: The dose is set, and you’ll get blood tests less often.

Does Hydroxyurea Cause Side Effects?

Most people who take hydroxyurea do well and don’t notice any side effects. Those who do might have dark fingernails or headaches. Often, side effects go away quickly as a person adjusts to the new medicine.

How Much Does Hydroxyurea Cost?

Hydroxyurea is usually paid for by insurance. Your cost (if any) will depend on the type of insurance you have. Your doctor’s office will help you find out if there are costs for you.

If your care team recommends hydroxyurea, talk to them if you have any questions or concerns. Talk it over with a parent too. Soon you’ll be ready to make a choice you can feel good about.

Medically reviewed by: Corinna L. Schultz, MD
Date reviewed: November 2022