Hydrea (hydroxyurea) is a well-established antineoplastic and antimetabolite medication, primarily indicated for the management of certain chronic myeloproliferative disorders. It is a cornerstone therapy in hematologic oncology, known for its cytoreductive properties. By inhibiting ribonucleotide reductase, it interferes with DNA synthesis, effectively controlling the overproduction of abnormal blood cells. This oral medication offers a critical therapeutic option for patients requiring precise control over their condition, supported by decades of clinical use and research.

Features

• Active ingredient: Hydroxyurea
• Available in 500 mg capsule form
• Prescription-only medication
• Manufactured under strict pharmaceutical standards
• Oral administration for patient convenience
• Standardized dosing based on body surface area or weight

Benefits

• Effectively reduces elevated white blood cell, platelet, and red blood cell counts in myeloproliferative disorders
• Decreases frequency of painful crises in sickle cell anemia by increasing fetal hemoglobin production
• Provides palliative treatment for resistant solid tumors when other therapies have failed
• Offers oral administration convenience compared to intravenous chemotherapies
• Demonstrates well-characterized safety profile with extensive clinical experience
• Allows for dose titration based on individual patient response and tolerance

Common use

Hydrea is primarily prescribed for the treatment of chronic myelogenous leukemia (CML), essential thrombocythemia, and polycythemia vera. It is also FDA-approved for the management of sickle cell anemia in adult patients, where it reduces the frequency of painful crises and the need for blood transfusions. Additionally, it may be used as adjunctive therapy in combination with radiation treatment for advanced squamous cell carcinomas of the head and neck (excluding lip cancer). Off-label uses include treatment for other myeloproliferative disorders and certain resistant solid tumors, though these applications require careful medical supervision.

Dosage and direction

Dosage must be individualized based on the patient’s diagnosis, body weight, hematologic parameters, and clinical response. For solid tumors, the typical initial dose is 80 mg/kg administered as a single dose every third day, or 20-30 mg/kg administered as a single daily dose. For resistant chronic myelogenous leukemia, the recommended initial dose is 20-30 mg/kg administered as a single daily dose. For sickle cell anemia, the initial dose is 15 mg/kg/day as a single dose, which may be increased by 5 mg/kg/day every 12 weeks until maximum tolerated dose or 35 mg/kg/day is reached. Capsules should be swallowed whole with water, and patients should not open, crush, or chew them. Dosing should be based on ideal or actual body weight, whichever is less. Complete blood counts should be monitored weekly during therapy.

Precautions

Hydrea requires careful hematologic monitoring due to its myelosuppressive effects. Weekly blood counts are recommended during therapy, with more frequent monitoring if significant suppression occurs. Patients should be advised to report any signs of infection, bleeding, or unusual bruising promptly. Hydrea may cause fetal harm when administered to pregnant women, requiring effective contraception during treatment. The medication may impair fertility in both males and females. Caution is advised in patients with renal impairment, as hydroxyurea is primarily excreted by the kidneys. Regular monitoring of renal function is recommended, with dose adjustments necessary for patients with creatinine clearance below 60 mL/min. Patients should avoid vaccination with live vaccines during treatment.

Contraindications

Hydrea is contraindicated in patients with severe bone marrow suppression evidenced by leukopenia (WBC <2500/mm³), thrombocytopenia (platelets <100,000/mm³), or severe anemia. It should not be used in patients with known hypersensitivity to hydroxyurea or any component of the formulation. The medication is contraindicated in women who are pregnant or breastfeeding unless the potential benefit justifies the potential risk to the fetus or infant. Use is also contraindicated in patients with severe renal impairment (creatinine clearance <30 mL/min) without appropriate dose adjustment and careful monitoring.

Possible side effect

Myelosuppression is the most common side effect, manifesting as leukopenia, anemia, and thrombocytopenia. Gastrointestinal disturbances including nausea, vomiting, diarrhea, constipation, and stomatitis may occur. Dermatologic reactions such as maculopapular rash, facial erythema, and alopecia have been reported. Neurological side effects including headache, dizziness, and drowsiness may occur. Rare but serious adverse effects include pulmonary fibrosis, hepatotoxicity, and vascular ulcers. Long-term use has been associated with secondary malignancies in some patients. Patients may experience nail discoloration and nail bed changes.

Drug interaction

Hydrea may enhance the toxicity of other myelosuppressive agents when used concomitantly. Live vaccines should be avoided due to potential for enhanced replication of vaccine virus. Concurrent use with interferon may increase the risk of cutaneous vasculitis. Antiretroviral agents, particularly didanosine and stavudine, may have increased toxicity when combined with hydroxyurea. The medication may potentiate the effects of radiation therapy, requiring careful monitoring when used concurrently. Drugs that affect renal function may alter hydroxyurea clearance and require dose adjustment.

Missed dose

If a dose is missed, patients should take it as soon as remembered unless it is almost time for the next scheduled dose. In that case, the missed dose should be skipped, and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed one. If multiple doses are missed or vomiting occurs shortly after administration, patients should contact their healthcare provider for guidance. Maintaining consistent dosing is important for therapeutic efficacy, so patients should establish routines to promote adherence.

Overdose

Acute overdose may manifest as exacerbation of adverse effects, particularly myelosuppression, mucositis, and gastrointestinal toxicity. Symptoms may include severe leukopenia, thrombocytopenia, anemia, and nausea/vomiting. Management involves immediate discontinuation of the drug and supportive care, including transfusion of blood products if indicated. Hemodialysis may be effective in removing hydroxyurea due to its relatively low molecular weight and water solubility. There is no specific antidote for hydroxyurea overdose. Treatment should be directed at supporting hematologic parameters and managing specific symptoms.

Storage

Hydrea capsules should be stored at controlled room temperature between 20°C to 25°C (68°F to 77°F), with excursions permitted between 15°C to 30°C (59°F to 86°F). The medication should be kept in its original container, tightly closed, and protected from moisture. It should be stored out of reach of children and pets. Unused medication should be properly disposed of according to local regulations, not flushed down the toilet or thrown in household trash unless instructed to do so. Capsules should be protected from light and excessive heat.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Hydrea is a prescription medication that should only be used under the supervision of a qualified healthcare professional. Patients should not make any changes to their treatment regimen without consulting their physician. The information provided here may not include all possible uses, directions, precautions, or interactions. Healthcare providers should reference the complete prescribing information before initiating therapy. Individual patient responses may vary, and treatment decisions should be based on professional medical judgment.

Reviews

Clinical studies and patient reports consistently demonstrate Hydrea’s efficacy in controlling blood counts in myeloproliferative disorders. Many hematologists consider it a first-line therapy for polycythemia vera and essential thrombocythemia due to its predictable response and manageable side effect profile. In sickle cell disease, patients report significant reduction in crisis frequency and improved quality of life. Some patients note gastrointestinal discomfort as a challenging side effect, though this often improves with dose adjustment or supportive medications. Long-term users appreciate the oral formulation’s convenience compared to intravenous alternatives. Healthcare providers emphasize the importance of regular monitoring to maximize benefits while minimizing risks.