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Hydrea Dosage

Generic name: hydroxyurea 500mg
Dosage form: capsule

The information at is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

Procedures for proper handling and disposal of cytotoxic drugs should be considered. Several guidelines on this subject have been published.1-4

To minimize the risk of dermal exposure, always wear impervious gloves when handling bottles containing HYDREA capsules. HYDREA capsules should not be opened. Personnel should avoid exposure to crushed or opened capsules. If contact with crushed or opened capsules occurs, wash immediately and throroughly. More information is available in the references listed below.

Because of the rarity of melanoma, resistant chronic myelocytic leukemia, carcinoma of the ovary, and carcinomas of the head and neck in pediatric patients, dosage regimens have not been established.

All dosage should be based on the patient’s actual or ideal weight, whichever is less. Concurrent use of HYDREA with other myelosuppressive agents may require adjustment of dosages.

Since hydroxyurea may raise the serum uric acid level, dosage adjustment of uricosuric medication may be necessary.

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 hydroxyurea should begin at least seven 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 evidences no unusual or severe reactions.

Resistant Chronic Myelocytic Leukemia

Until the intermittent therapy regimen has been evaluated, CONTINUOUS therapy (20-30 mg/kg administered orally as a single dose daily) is recommended.

An adequate trial period for determining the antineoplastic effectiveness of hydroxyurea is six 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 reevaluated after three days, and therapy resumed when the counts return to acceptable levels. Since the hematopoietic rebound is prompt, it is usually necessary to omit only a few doses. If prompt rebound has not occurred during combined HYDREA 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. Severe anemia, if it occurs, should be corrected without interrupting hydroxyurea therapy. Because hematopoiesis may be compromised by extensive irradiation or by other antineoplastic agents, it is recommended that hydroxyurea 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, 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.

Renal Insufficiency

As renal excretion is a pathway of elimination, consideration should be given to decreasing the dosage of HYDREA in patients with renal impairment. (See PRECAUTIONS and CLINICAL PHARMACOLOGY.) Close monitoring of hematologic parameters is advised in these patients.

Hepatic Insufficiency

There are no data that support specific guidance for dosage adjustment in patients with hepatic impairment. Close monitoring of hematologic parameters is advised in these patients.