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Generic NameBrand Name
hydroxyurea Hydrea

Hydroxyurea is available as a pill you can swallow. It is also known as hydroxycarbamide.

How It Works

Hydroxyurea is used to lower the white blood cell count for people who have a disease like leukemia where the body makes too many white blood cells. It may be used to treat people who haven't been helped by other treatments such as tyrosine kinase inhibitors (TKIs).

It is used to treat chronic myelogenous leukemia (CML) and, rarely, chronic lymphocytic leukemia (CLL) or acute myelogenous leukemia (AML). It is sometimes used to treat sickle cell disease.

Why It Is Used

Hydroxyurea is used to lower blood counts in people who have some kinds of leukemia. It works fast, does not have serious side effects, and allows for a quick recovery if blood counts drop too low.1

How Well It Works

Some leukemias can cause your white blood cell count to get too high. Hydroxyurea can reduce white blood cell counts within 1 or 2 days.1

Side Effects

Side effects of hydroxyurea are generally mild and can include:

  • Low blood counts, which may increase the risk of infection and bleeding.
  • Nausea or vomiting.
  • Loss of appetite.
  • Diarrhea.
  • Hoarseness.
  • Fever or chills.
  • Mouth sores (stomatitis).
  • Blackening of the fingernails and toenails.
  • Skin ulcers (uncommon side effect).
  • Rashes.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Hydroxyurea should be used only under the supervision of a medical oncologist or hematologist. He or she will monitor your blood counts regularly.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Pregnancy advice for women and men

If you need to take this medicine, talk to your doctor about how you can prevent pregnancy.

For women: Do not use this medicine if you are pregnant or planning to get pregnant.

For men: Do not use this medicine if you and your partner are planning to get pregnant.


Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Hydroxyurea is still an experimental treatment in children. Long-term effects of the drug on children are not yet known.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.



  1. Reichard KK, et al. (2009). Chronic myeloid leukemia. In JP Greer et al., eds., Wintrobe's Clinical Hematology, 12th ed., vol. 2, pp. 2006–2030. Philadelphia: Lippincott Williams and Wilkins.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer Brian Leber, MDCM, FRCPC - Hematology
Last Revised February 9, 2011

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.