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Generic Name: hydroxyurea (hye DROX ee yoo REE a)
Brand Name: Droxia, Hydrea, Mylocel

What is hydroxyurea?

Hydroxyurea affects certain cells in the body, such as cancer cells or sickled red blood cells.

Hydroxyurea is used to treat chronic myeloid leukemia, ovarian cancer, and certain types of skin cancer (squamous cell cancer of the head and neck).

Hydroxyurea is also used to reduce pain episodes and the need for blood transfusions in people with sickle cell anemia. Hydroxyurea will not cure sickle cell anemia.

Hydroxyurea may also be used for purposes not listed in this medication guide.

What is the most important information I should know about hydroxyurea?

Hydroxyurea can weaken your immune system. Your blood will need to be tested often, and your cancer treatments may be delayed.

Using hydroxyurea may increase your risk of developing other types of cancer, such as leukemia or skin cancer. Wear protective clothing and use sunscreen when you are outdoors.

What should I discuss with my healthcare provider before taking hydroxyurea?

You should not use hydroxyurea if you are allergic to it.

To make sure hydroxyurea is safe for you, tell your doctor if you have:

  • bone marrow suppression or anemia (low red blood cells);

  • low levels of platelets in your blood;

  • a history of skin cancer;

  • high levels of uric acid in your blood;

  • HIV or AIDS;

  • kidney disease (or if you are on dialysis);

  • liver disease;

  • a pancreas disorder; or

  • if you are receiving chemotherapy or radiation.

Using hydroxyurea may increase your risk of developing other types cancer or leukemia. Talk with your doctor about your specific risk.

This medicine can harm an unborn baby or cause birth defects. Do not use if you are pregnant.

Both men and women taking this medicine should use birth control to prevent pregnancy. Hydroxyurea use by either parent may cause birth defects. After the last dose of hydroxyurea, a man must use birth control for much longer than a woman.

  • For women: Use effective birth control to prevent pregnancy while you are using this medicine and for at least 6 months after your treatment ends.

  • For men: Use birth control to prevent pregnancy while using hydroxyurea and for at least 1 year after your treatment ends.

This medication can also affect fertility (your ability to have children), whether you are a man or a woman.

Hydroxyurea can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are taking hydroxyurea.

Older adults may be more likely to have side effects from this medicine.

How should I take hydroxyurea?

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Drink 8 to 10 glasses of liquid per day while you are taking hydroxyurea. You may take the medicine with or without food.

Hydroxyurea is either taken once per day or once every third day, depending on the condition being treated. On each of your dosing days, take the medicine at the same time of day. Your doctor may also want you to take a folic acid supplement. Follow your doctor's instructions very carefully.

Wash your hands before and after you handle a hydroxyurea capsule or the bottle that contains the pills. For best protection, wear disposable gloves when handling the pills.

Do not open the hydroxyurea capsule. Do not use a pill that has been accidentally opened or broken. The medicine from an open capsule can be dangerous if it gets in your eyes, mouth, or nose, or on your skin. If this occurs, wash your skin with soap and water or rinse your eyes with water.

If any powder from an open capsule is spilled, wipe it up at once with a damp paper towel and throw the towel away in a sealed plastic bag where children and pets cannot get to it.

Hydroxyurea can lower blood cells that help your body fight infections and help your blood to clot. Your blood will need to be tested often. Your cancer treatments may be delayed based on the results of these tests.

This medication can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using hydroxyurea.

Use hydroxyurea regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include drowsiness, mouth sores, and swelling with pain and purple discoloration in your hands and feet.

What should I avoid while taking hydroxyurea?

Using hydroxyurea may increase your risk of developing skin cancer. Avoid exposure to sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Do not receive a "live" vaccine while using hydroxyurea, or you could develop a serious infection. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Do not handle hydroxyurea pills or the medicine bottle without skin protection (disposable gloves).

This medicine can pass into body fluids (urine, feces, vomit). Caregivers should wear rubber gloves while cleaning up a patient's body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.

Hydroxyurea side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • skin numbness or purple discoloration, skin ulcers or open sores;

  • painful or difficult urination;

  • numbness, tingling, or burning pain in your hands or feet;

  • signs of a weak immune system--fever, chills, body aches, flu symptoms, sores in your mouth and throat, pale skin, feeling light-headed or short of breath, easy bruising or bleeding;

  • pancreas problems--severe pain in your upper stomach spreading to your back, nausea and vomiting, fast heart rate; or

  • liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

  • bleeding;

  • loss of appetite, upset stomach, constipation, diarrhea, vomiting;

  • skin peeling or itching, mild rash;

  • hair loss, darkening of your nails;

  • headache, dizziness; or

  • swelling in your hands or feet.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Hydroxyurea dosing information

Usual Adult Dose for Solid Tumors:

-INTERMITTENT THERAPY: 80 mg/kg administered orally as a single dose every third day
-CONTINUOUS THERAPY: 20 to 30 mg/kg administered orally as a single dose daily
-CONCOMITANT THERAPY WITH IRRADIATION: Carcinoma of the head and neck: 80 mg/kg administered orally as a single dose every third day

-Administration of therapy should be begun at least 7 days before initiation of irradiation and continued during radiotherapy as well as indefinitely afterwards provided that the patient may be kept under adequate observation and there is no evidence of unusual or severe reactions.
-Pain or discomfort from inflammation of the mucous membranes at the irradiated site (mucositis) is usually controlled by measures such as topical anesthetics and orally administered analgesics. If the reaction is severe, hydroxyurea therapy may be temporarily interrupted; if it is extremely severe, irradiation dosage may, in addition, be temporarily postponed. However, it has rarely been necessary to terminate these therapies.
-Severe gastric distress, such as nausea, vomiting, and anorexia, resulting from combined therapy may usually be controlled by temporary interruption of hydroxyurea administration.

-Significant tumor response to this drug has been demonstrated in melanoma, resistant chronic myelocytic leukemia, and recurrent, metastatic, or inoperable carcinoma of the ovary.
-This drug used concomitantly with irradiation therapy is intended for use in the local control of primary squamous cell (epidermoid) carcinomas of the head and neck, excluding the lip.

Usual Adult Dose for Sickle Cell Anemia:

INITIAL DOSE: 15 mg/kg per day as a single dose
MAXIMUM DOSE: 35 mg/kg/day

-Counts in acceptable range: Increase dose 5 mg/kg/day every 12 weeks to a maximum dose of 35 mg/kg/day
-Counts between acceptable and toxic range: Do not increase dose. If in toxic range, discontinue therapy until hematologic recovery.
-Dosing after hematologic recovery: Reduce dose by 2.5 mg/kg/day. Reduce the dose from the dose associated with hematologic toxicity. May titrate up or down every 12 weeks in 2.5 mg/kg/day increments. The patient should be at a stable dose with no hematologic toxicity for 24 weeks. Discontinue treatment permanently if a patient develops hematologic toxicity twice.

Neutrophils greater than or equal to 2500 cells/mm3
Platelets greater than or equal to 95,000/mm3
Reticulocytes greater than or equal to 95,000/mm3 if the hemoglobin concentration is less than 9 g/dL
Neutrophils less than 2000 cells/mm3
Platelets less than 80,000/mm3
Hemoglobin less than 4.5 g/dL
Reticulocytes less than 80,000/mm3 if the hemoglobin concentration is less than 9 g/dL

-Dosage is based on the actual or ideal patient weight, whichever is less.
-The patient blood count should be monitored every 2 weeks.
-Fetal hemoglobin (HbF) levels may be used to evaluate the efficacy of therapy in clinical use. Obtain HbF levels every 3 to 4 months. Monitor for an increase in HbF of at least 2-fold over the baseline value.
-Prophylactic administration of folic acid is recommended.

Use: To reduce the frequency of painful crises and to reduce the need for blood transfusions in patients with sickle cell anemia with recurrent moderate to severe painful crises.

Usual Adult Dose for Chronic Myelogenous Leukemia:

Until the intermittent therapy regimen has been evaluated, continuous therapy at 20 to 30 mg/kg administered orally as a single dose per day is recommended.

-An adequate trial period for determining the antineoplastic effectiveness of this drug is 6 weeks of therapy. When there is regression in tumor size or arrest in tumor growth, therapy should be continued indefinitely.
-Therapy should be interrupted if the white blood cell count drops below 2500/mm3, or the platelet count below 100,000/mm3. In these cases, the counts should be rechecked after 3 days, and therapy resumed when the counts rise significantly toward normal values. Since the hematopoietic rebound is prompt, it is usually necessary to omit only a few doses. If prompt rebound has not occurred during combined drug and irradiation therapy, irradiation may also be interrupted. However, the need for postponement of irradiation has been rare. Radiotherapy has usually been continued using the recommended dosage and technique.
-If severe anemia occurs, it should be corrected without interrupting therapy. Because hematopoiesis may be compromised by extensive irradiation or by other antineoplastic agents, it is recommended that this drug be administered cautiously to patients who have recently received extensive radiation therapy or chemotherapy with other cytotoxic drugs.
-Pain or discomfort from inflammation of the mucous membranes at the irradiated site (mucositis) is usually controlled by measures such as topical anesthetics and orally administered analgesics. If the reaction is severe, therapy may be temporarily interrupted; if it is extremely severe, irradiation dosage may, in addition, be temporarily postponed. However, it has rarely been necessary to terminate these therapies.
-Severe gastric distress, such as nausea, vomiting, and anorexia, resulting from combined therapy may usually be controlled by temporary interruption of this drug.

-Resistant chronic myeloid leukemia

What other drugs will affect hydroxyurea?

Some medicines can increase your risk of certain side effects while taking hydroxyurea. Tell your doctor if you are also using didanosine, stavudine, or an interferon (such as Actimmune, Alferon, Avonex, Betaseron, Extavia, Infergen, Intron, Rebetron, Rebif, or Roferon).

Other drugs may interact with hydroxyurea, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

  • Your pharmacist can provide more information about hydroxyurea.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 9.06.

Date modified: October 14, 2016
Last reviewed: April 18, 2016