Hydrea (Hydroxycarbamide)

Hydrea is prescribed for a range of hematologic disorders where abnormal cell proliferation is a concern.

• Chronic myelogenous leukemia (CML)
• Sickle cell disease to reduce painful crises
• Essential thrombocythemia for platelet count control
• Polycythemia vera to lower red blood cell mass
• Off‑label use in certain myeloproliferative neoplasms

• Hydroxycarbamide inhibits ribonucleotide reductase, the enzyme responsible for converting ribonucleotides to deoxyribonucleotides. By reducing the pool of deoxyribonucleotides, the drug limits DNA synthesis and cell replication, particularly affecting rapidly dividing hematopoietic cells. This antimetabolite action leads to decreased proliferation of malignant or abnormal blood cells, contributing to disease control in myeloproliferative conditions.

Hydrea may cause a variety of adverse reactions, ranging from mild to severe.

Common

• Nausea and vomiting
• Loss of appetite
• Fatigue or weakness
• Mild hair thinning
• Low white blood cell count (leukopenia)
• Elevated liver enzymes

Serious

• Severe bone marrow suppression (pancytopenia)
• Acute kidney injury
• Life‑threatening infections
• Severe skin reactions such as Stevens‑Johnson syndrome

Before starting Hydrea, patients should discuss their medical history and current health status with a healthcare professional.

• Monitor complete blood counts regularly to detect bone marrow suppression.
• Assess liver and kidney function before and during therapy.
• Use effective contraception; pregnancy safety is unknown.
• Avoid use in patients with known hypersensitivity to hydroxycarbamide.
• Caution in individuals with pre‑existing immunosuppression or active infections.
• Discuss any planned surgeries, as wound healing may be impaired.

Hydrea can interact with several medications, altering its efficacy or increasing toxicity.

Avoid

• Concurrent use of other myelosuppressive agents (e.g., chemotherapy, azathioprine) due to heightened risk of severe cytopenias.
• Live vaccines, because immunosuppression may reduce vaccine effectiveness and increase infection risk.

Use with caution

• Allopurinol, which may increase hydroxycarbamide plasma levels.
• NSAIDs, as they can exacerbate gastrointestinal irritation.
• Anticoagulants, because altered platelet counts may affect bleeding risk.
• Drugs affecting renal function, such as ACE inhibitors, may require dose adjustments.