Hydroxyurea (Systemic)

Brand name(s): Hydrea

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For hydroxyurea, the following should be considered:

Allergies-Tell your doctor if you have ever had any unusual or allergic reaction to hydroxyurea.

Pregnancy-Tell your doctor if you are pregnant or if you intend to have children. There is a chance that this medicine may cause birth defects if either the male or female is taking it at the time of conception or if it is taken during pregnancy. Studies have shown that hydroxyurea causes birth defects in animals. In addition, many cancer medicines may cause sterility. Although sterility seems to be only temporary with this medicine, the possibility should be kept in mind.

Be sure that you have discussed this with your doctor before taking this medicine. It is best to use some kind of birth control while you are taking hydroxyurea. Tell your doctor right away if you think you have become pregnant while taking hydroxyurea.

Breast-feeding-Hydroxyurea passes into human breast milk. Tell your doctor if you are breast-feeding or if you intend to breast-feed during treatment with this medicine. Because hydroxyurea may cause serious side effects, breast-feeding is not recommended while you are taking it.

Children-Side effects may be likely to occur in children, who may be more sensitive to the effects of hydroxyurea.

Older adults-Side effects may be more likely to occur in the elderly, who may be more sensitive to the effects of hydroxyurea.

Other medicines-Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking hydroxyurea, it is especially important that your health care professional know if you are taking any of the following:

• Amphotericin B by injection (e.g., Fungizone) or
• Antithyroid agents (medicine for overactive thyroid) or
• Azathioprine (e.g., Imuran) or
• Chloramphenicol (e.g., Chloromycetin) or
• Colchicine or
• Cyclophosphamide (e.g., Cytoxan) or
• Flucytosine (e.g., Ancobon) or
• Ganciclovir (e.g., Cytovene) or
• Interferon (e.g., Intron A, Roferon-A) or
• Mercaptopurine (e.g., Purinethol) or
• Methotrexate (e.g., Rheumatrex) or
• Plicamycin (e.g., Mithracin) or
• Zidovudine (e.g., AZT, Retrovir) or
• If you have ever been treated with x-rays or other cancer medicines-Hydroxyurea may increase the effects of these medicines or radiation therapy on the blood

• Probenecid (e.g., Benemid) or
• Sulfinpyrazone (e.g., Anturane)-Hydroxyurea may increase the amount of uric acid in the blood. Since these medicines are used to lower uric acid levels, they may not be as effective in patients taking hydroxyurea

• Abacavir (e.g., ABC, Ziagen) or
• Abacavir/Lamivudine/Zidovudine (e.g., Trizivir) or
• Amprenavir (e.g., Agenerase) or
• Delavirdine (e.g., Rescriptor) or
• Didanosine (e.g., ddI, Videx) or
• Efavirenz (e.g., Sustiva) or
• Indinavir (e.g., Crixivan) or
• Lamivudine (e.g., 3TC, Epivir) or
• Lamivudine/Zidovudine (e.g., Combivir) or
• Lopinavir/Ritonavir (e.g., Kaletra) or
• Nelfinavir (e.g., Viracept) or
• Nevirapine (e.g., Viramune) or
• Ritonavir (e.g., Norvir) or
• Saquinavir (e.g., Fortovase) or
• Saquinavir mesylate (e.g., Invirase) or
• Stavudine (e.g. D4T, Zerit) or
• Zalcitabine (e.g., ddC, HIVID) or
• Zidovudine (e.g., AZT, Retrovir, ZDV)-Hydroxyurea may increase the effects of these medicines on the liver, pancreas, and nerves

Other medical problems-The presence of other medical problems may affect the use of hydroxyurea. Make sure you tell your doctor if you have any other medical problems, especially:

• Anemia or
• Leukopenia or
• Neutropenia or
• Thrombocytopenia-May worsen and affect the decision to continue therapy

• Chickenpox (including recent exposure) or
• Herpes zoster (shingles)-Risk of severe disease affecting other parts of the body

• Gout or
• Kidney stones-Hydroxyurea may increase levels of uric acid in the body, which can cause gout or kidney stones

• Infection (especially AIDS or HIV)-Hydroxyurea may decrease your body's ability to fight infection or cause serious liver, pancreas, or peripheral nerve reactions with certain specific HIV treatments

• Kidney disease-Effects may be increased because of slower removal of hydroxyurea from the body

Last Revised: 07/09/2002