Hydroxyurea can cause a severe decrease in the number of blood cells in your bone marrow. This may cause certain symptoms and may increase the risk that you will develop a serious infection or bleeding. If you experience any of the following symptoms, call your doctor immediately: fever, sore throat, ongoing cough and congestion, or other signs of infection; unusual bleeding or bruising; bloody or black, tarry stools; bloody vomit; or vomiting blood or brown material that resembles coffee grounds.
Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests on a regular basis to check your body's response to hydroxyurea and to see if your blood count has dropped. Your doctor may need to change your dose or tell you to stop taking hydroxyurea for a period of time to allow your blood count to return to normal if it has dropped too low.
Hydroxyurea may increase the risk that you will develop other cancers. Talk with your doctor about the risks of taking hydroxyurea.
Why is this medication prescribed?
Hydroxyurea is used to treat a certain type of chronic myelogenous leukemia (CML; a type of cancer of the white blood cells). It is also used to treat ovarian cancer (cancer that begins in the female reproductive organs where eggs are formed), melanoma (a type of skin cancer), and certain types of head and neck cancer (including cancer of the mouth, cheek, tongue, throat, tonsils, and sinuses). Hydroxyurea is also used to reduce the frequency of painful crises and reduce the need for blood transfusions in patients with sickle cell anemia (an inherited blood disorder in which the red blood cells are abnormally shaped [shaped like a sickle] and cannot bring enough oxygen to all parts of the body). Hydroxyurea is in a class of medications called antimetabolites. Hydroxyurea treats cancer by slowing or stopping the growth of cancer cells in your body. Hydroxyurea treats sickle cell anemia by helping to prevent formation of sickle-shaped red blood cells.
How should this medicine be used?
Hydroxyurea comes as a capsule to take by mouth. It is usually taken once a day. When hydroxyurea is used to treat certain types of cancer, it may be taken once every third day. Take hydroxyurea at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take hydroxyurea exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor may need to delay your treatment or adjust your dose of hydroxyurea depending on your response to treatment and any side effects that you may experience. Talk to your doctor about how you are feeling during your treatment. Do not stop taking hydroxyurea without talking to your doctor.
Your doctor will probably tell you to take another medication, folic acid (a vitamin), to decrease some of the side effects of this medication. Take this medication exactly as directed.
Swallow the capsules whole; do not split, chew, or crush them.
You should wear rubber or latex gloves when you handle the capsules so that your skin does not come into contact with the capsules. Wash your hands before and after you touch the bottle or capsules. If the powder from a capsule spills, wipe it up immediately with a damp disposable towel. Then place the towel in a closed container, such as a plastic bag and throw it away in a trash can that is out of the reach of children and pets.
Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.
Other uses for this medicine
Hydroxyurea is also sometimes used to treat polycythemia vera (a blood disease in which your body makes too many red blood cells). Talk to your doctor about the risks of using this medication for your condition.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking hydroxyurea,
- tell your doctor and pharmacist if you are allergic to hydroxyurea, any other medications, or any of the inactive ingredients in hydroxyurea capsules. Ask your pharmacist for a list of the ingredients.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: certain medications for HIV (human immunodeficiency virus) or AIDS (acquired immunodeficiency syndrome) such as didanosine (Videx), indinavir (Crixivan) and stavudine (Zerit); interferon (Actimmune, Avonex, Betaseron, Intron A, Infergen, and others); medications that suppress the immune system such as azathioprine (Imuran), cyclosporine (Neoral, Sandimmune), methotrexate (Rheumatrex), sirolimus (Rapamune), and tacrolimus (Prograf); probenecid; or sulfinpyrazone (Anturane). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you have human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS); if you are being treated with or have ever been treated with radiation therapy or cancer chemotherapy; or if you have or have ever had kidney or liver disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. You should not become pregnant or breast-feed while you are taking hydroxyurea. If you become pregnant while taking hydroxyurea, call your doctor immediately. Hydroxyurea may harm the fetus.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
Hydroxyurea may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- loss of appetite
- weight gain
- sores in the mouth and throat
- pale skin
- hair loss
- darkening of skin and nails
Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment:
- excessive tiredness or weakness
- fast heartbeat
- shortness of breath
- ongoing pain that begins in the stomach area, but may spread to the back
- pain, itching, redness, swelling, blisters, or sores on the skin
- pain in the upper right part of the stomach
- yellowing of the skin or eyes
- flu-like symptoms
- numbness, burning, or tingling in the hands or feet
- difficult or painful urination
Hydroxyurea may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children and pets. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include the following:
- sores in the mouth and throat
- pain, redness, swelling, and scaling on the hands and feet
- darkening of the skin
What other information should I know?
Do not let anyone else take your medication. People who are not taking hydroxyurea should avoid touching hydroxyurea capsules or the bottle that contains the capsules.
Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.