hydroxyurea

hydroxyurea /hy·droxy·urea/ (-u-re´ah) an antineoplastic that inhibits a step in DNA synthesis, used in treatment of chronic granulocytic leukemia, some carcinomas, malignant melanoma, and polycythemia vera. It is also used to reduce the frequency of painful sickle cell crisis.

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hy·drox·y·u·re·a (h-drks-y-r)

n.

An antineoplastic drug that suppresses the production of blood cell precursors in the bone marrow and is used in the treatment of certain leukemias, carcinomas, and sickle cell anemia.

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Hydroxyurea

A drug that has been shown to induce production of fetal hemoglobin. Fetal hemoglobin has a pair of gamma-globin molecules in place of the typical beta-globins of adult hemoglobin. Higher-than-normal levels of fetal hemoglobin can ameliorate some of the symptoms of thalassemia.

Mentioned in: Hemoglobinopathies, Sickle Cell Disease, Thalassemia

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hydroxyurea

[hīdrok′siyoo͡rē′ə]

an antineoplastic.

indications It is prescribed in the treatment of a variety of neoplasms and other conditions involving the blood and by itself or as a radiosensitizer for the treatment of other cancers, including those involving the brain, head and neck, lungs, kidneys, ovaries, and prostate.

contraindications Bone marrow depression or known hypersensitivity to this drug prohibits its use. It is not to be given to women who are or may become pregnant.

adverse effects The most serious adverse effect is bone marrow depression. GI disturbances and dermatitis also may occur.

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hydroxyurea (hīdrok´sēyrē´),

n brand name: Hydrea;
drug class: antineoplastic;
action: acts by inhibiting DNA synthesis without interfering with synthesis of RNA or protein;
uses: melanoma, chronic myelocytic leukemia, recurrent or metastatic ovarian cancer.

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hydroxyurea

an antineoplastic agent that blocks the conversion of ribonucleotides to deoxyribonucleotides, thus stopping DNA synthesis. Called also hydroxycarbamide.

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hydroxyurea Warning - Hazardous drug!

Droxia, Hydrea

Pharmacologic class: Antimetabolite

Therapeutic class: Antineoplastic

Pregnancy risk category D

FDA Boxed Warning

• Drug may cause severe and even life-threatening adverse effects. Administer under supervision of physician experienced in using drug to treat sickle cell anemia.
• Drug damages genes, chromosomes, and DNA and may be carcinogenic. Secondary leukemias have occurred in patients receiving it as long-term therapy for myeloproliferative disorders. Prescriber and patient must carefully weigh potential benefits against undefined risk of secondary cancers.

Action

Unknown. May inhibit enzyme necessary for DNA synthesis without disrupting RNA or protein synthesis.

Availability

Capsules: 200 mg, 250 mg, 300 mg, 400 mg, 500 mg

⊘Indications and dosages

➣ Head and neck cancer; ovarian cancer; malignant melanoma

Adults: 60 to 80 mg/kg (2 to 3 g/m²) P.O. as a single daily dose q 3 days, or 20 to 30 mg/kg/day P.O. as a single dose. Begin therapy 7 days before radiation.

➣ Resistant chronic myelogenous leukemia

Adults: 20 to 30 mg/kg/day P.O. in one or two divided doses

➣ Sickle cell anemia

Adults and children: 15 mg/kg/day P.O. as a single dose. May increase by 5 mg/kg/day P.O. q 12 weeks, up to 35 mg/kg/day.

Off-label uses

• Thrombocythemia
• Human immunodeficiency virus

Contraindications

• Hypersensitivity to drug or tartrazine
• Bone marrow depression
• Severe anemia or thrombocytopenia

Precautions

Use cautiously in:
• renal or hepatic impairment
• obese patients
• females of childbearing age
• elderly patients.

Administration

• Provide frequent mouth care.

Route	Onset	Peak	Duration
P.O.	Unknown	2 hr	24 hr

Adverse reactions

CNS: drowsiness, malaise, confusion, dizziness, headache

GI: nausea, vomiting, diarrhea, constipation, stomatitis, anorexia

GU: dysuria, hyperuricemia, infertility, renal tubular dysfunction

Hematologic: anemia, megaloblastosis, leukopenia, thrombocytopenia, bone marrow depression

Hepatic: hepatitis

Metabolic: hyperuricemia

Skin: alopecia, erythema, pruritus, rash, urticaria, exacerbation of post-radiation erythema

Other: chills, fever

Interactions

Drug-drug. Live-virus vaccines: decreased antibody response to vaccine, increased risk of adverse reactions

Myelosuppressants: additive bone marrow depression

Drug-diagnostic tests. Blood urea nitrogen, creatinine, uric acid: increased values

Hemoglobin, platelets, red blood cells, white blood cells: decreased values

Mean corpuscular volume: transient increase

Patient monitoring

• Assess CBC weekly.
• Closely monitor patient with renal or hepatic impairment. Check kidney and liver function tests often.
• Assess fluid status. Make sure patient drinks 10 to 12 glasses of water daily.

Patient teaching

• Advise patient to mark dates for drug doses, diagnostic tests, and treatments on calendar.
☞ Instruct patient to immediately report easy bruising, bleeding, unusual tiredness, or yellowing of skin or eyes.
• Tell patent to report such adverse effects as appetite loss, nausea, vomiting, oral lesions, constipation, diarrhea, confusion, dizziness, headache, and rash.
• Instruct female patient to use barrier contraception.
• Tell patient he'll undergo regular blood testing to monitor drug effects.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.

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hydroxyurea

Droxia^®, Hydrea^® A non-alkylating, myelosuppressive chemotherapeutic of low toxicity, used to treat myeloproliferative disorders and hemoglobinopathies AIDS HU ↓ HIV viral loads if given as part of a protease-sparing triple combination with nucleoside analogues ddI–
didanosine–Videx^® and d4T–stavudine–Zerit^®. See AIDS Hematology Hydroxyurea induces ↑ HbF synthesis in sickle cell–SC anemia, which may comprise 25% of the total Hb–the remainder is HbS–seemingly enough to prevent formation of HbS polymers, the bête noire of SC disease; hydroxyurea may be used to ↑ fetal Hb production–by ↑ γ-globulin production and ↑ RBC survival and ↓ bilirubin and LD in Pts with SC anemia; used in Pts with SC disease ≥ age 18, to prevent/↓ painful crises and ↓ need for blood transfusions, for Pts who have had at ≥3 painful crises in previous yr. See Sickle cell anemia Oncology Hydroxyurea is used as a single agent to control blast transformation in CML, manage P vera, essential thrombocythemia and, with prednisone, treat idiopathic hypereosinophilic syndrome; long-term therapy may prevent thrombosis; hydroxyurea therapy–HT has also been used to manage melanoma and inoperable ovarian CA Long-term effects Unknown; in Pts with P vera, leukemia is 3-fold higher in HT than in those treated with phlebotomy.