Hydrea (hydroxyurea) is an oral chemotherapeutic agent specifically formulated for the management of certain chronic blood disorders and solid tumors. As an antimetabolite, it exerts its therapeutic effect by inhibiting ribonucleotide reductase, a key enzyme necessary for DNA synthesis. This targeted mechanism allows for controlled reduction of elevated blood counts, particularly in conditions like polycythemia vera and essential thrombocythemia, helping to mitigate the risk of thrombotic events. Its well-established efficacy profile and oral administration make it a cornerstone in long-term hematologic management, offering patients a balance between therapeutic control and quality of life.

Features

• Active ingredient: Hydroxyurea
• Available in 500 mg capsules
• Oral administration
• Prescription-only medication
• Manufactured under strict pharmaceutical standards
• Stable shelf life of 24 months

Benefits

• Effectively reduces elevated hematocrit and platelet counts in myeloproliferative disorders
• Decreases risk of thrombosis and hemorrhage associated with blood hyperviscosity
• May reduce spleen size in patients with myelofibrosis
• Oral formulation enables convenient outpatient management
• Well-established safety profile with decades of clinical use
• Can be used as radiosensitizer in head and neck cancers

Common use

Hydrea is primarily indicated for the treatment of polycythemia vera, essential thrombocythemia, and chronic myeloid leukemia. It is also used in the management of sickle cell anemia to reduce the frequency of painful crises and the need for blood transfusions. In oncology, it serves as a radiosensitizer for advanced squamous cell carcinoma of the head and neck. Off-label uses include treatment of other myeloproliferative neoplasms and certain solid tumors where cytoreduction is clinically indicated.

Dosage and direction

Dosage must be individualized based on patient’s diagnosis, hematological parameters, and treatment response. For polycythemia vera and thrombocythemia, the initial dose is typically 15-20 mg/kg/day as a single dose. For sickle cell anemia, the starting dose is 15 mg/kg/day, which may be increased gradually. Capsules should be swallowed whole with water, and handling should be minimized to avoid skin contact. Regular blood count monitoring is essential, with dosage adjustments made based on laboratory values and clinical response.

Precautions

Regular monitoring of complete blood counts is mandatory, typically weekly during initial therapy and periodically thereafter. Use with caution in patients with renal impairment, as hydroxyurea is primarily renally excreted. Pregnancy must be excluded before initiation due to teratogenic potential. Patients should be advised about the importance of adequate hydration. Dental status should be evaluated before treatment initiation due to risk of mucositis. Sun exposure should be limited due to potential photosensitivity.

Contraindications

Hydrea is contraindicated in patients with severe bone marrow suppression (leukopenia, thrombocytopenia, or anemia), severe renal impairment (creatinine clearance <30 mL/min), and pregnancy. It should not be used in patients with known hypersensitivity to hydroxyurea or any component of the formulation. Breastfeeding is contraindicated during therapy. The medication is not recommended for patients with active infections that may be exacerbated by myelosuppression.

Possible side effect

Common side effects include myelosuppression (anemia, leukopenia, thrombocytopenia), nausea, vomiting, and diarrhea. Dermatological reactions such as rash, skin ulceration, and hyperpigmentation may occur. Gastrointestinal disturbances including stomatitis and anorexia are frequently reported. Less common but serious adverse effects include pulmonary fibrosis, hepatotoxicity, and neurological symptoms. Long-term use has been associated with secondary malignancies in some patient populations.

Drug interaction

Hydrea may enhance the toxicity of other myelosuppressive agents. Concurrent use with live vaccines is not recommended. Antiretroviral agents, particularly didanosine and stavudine, may have increased toxicity when combined with hydroxyurea. Drugs that affect renal function may alter hydroxyurea clearance. Caution is advised when administering with other medications that cause pancreatitis or hepatotoxicity.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly 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 administration. Consistent dosing is important for maintaining therapeutic effect, so patients should be counseled on adherence strategies.

Overdose

Acute overdose may manifest as exacerbated myelosuppression, mucositis, nausea, vomiting, and diarrhea. In severe cases, neurological toxicity including seizures and coma may occur. Management involves immediate discontinuation of the drug, supportive care, and hematological monitoring. Hemodialysis may be considered in cases of severe toxicity, particularly in patients with renal impairment. There is no specific antidote for hydroxyurea overdose.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in the original container. Protect from moisture and light. Keep tightly closed and out of reach of children. Do not store in bathroom cabinets where humidity levels may fluctuate. Unused medication should be disposed of properly according to local regulations for chemotherapeutic agents.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Treatment decisions must be made by qualified healthcare professionals based on individual patient circumstances. The prescribing physician should be consulted for specific dosage recommendations and management of adverse effects. Patients should not alter their treatment regimen without medical supervision.

Reviews

Clinical studies have demonstrated Hydrea’s efficacy in controlling blood counts in approximately 80% of patients with polycythemia vera. In sickle cell disease, it reduces painful crises by 50% in responsive patients. Many hematologists regard it as a first-line option for high-risk essential thrombocythemia patients. Patient satisfaction surveys indicate appreciation for the oral formulation and outpatient management, though some report concerns about long-term side effects. The medication receives generally positive expert evaluation for its risk-benefit profile in appropriate patient populations.