Hydroxyurea Medications

Hydroxyurea is an antineoplastic agent used to treat sickle cell anemia and certain cancers by inhibiting DNA replication in abnormal cells.

Hydrea

Hydroxyurea

$2.17 per pill

500mg

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About Hydroxyurea

Hydroxyurea is a synthetic antimetabolite that has been a mainstay therapy for several hematologic conditions since its approval in the early -s. It belongs to the class of ribonucleotide reductase inhibitors and works by limiting the synthesis of deoxyribonucleotides, thereby slowing cell proliferation. In clinical practice Hydroxyurea is most recognized for reducing painful crises in sickle cell disease, controlling the elevated blood counts seen in polycythemia vera, and managing chronic myeloid leukemia when other options are unsuitable. The drug is marketed under brand names such as Hydrea, Droxia, and Hydux, and generic versions are widely available through our online pharmacy. Apart from these approved uses, clinicians sometimes prescribe Hydroxyurea off-label for conditions like essential thrombocythemia or certain solid tumors, guided by emerging evidence. Understanding its mechanism of action, therapeutic timeline, and safety profile helps patients make informed decisions when they consider buying Hydroxyurea online.

What is Hydroxyurea?

Hydroxyurea is an antineoplastic agent classified as a ribonucleotide reductase inhibitor. The Health Sciences Authority of Singapore approved it for clinical use shortly after the United States FDA granted approval in 197 for chronic myeloid leukemia. Over the following decades the European Medicines Agency expanded the indication to include sickle cell disease and various myeloproliferative disorders. By targeting the enzyme ribonucleotide reductase, Hydroxyurea blocks the conversion of ribonucleotides to deoxyribonucleotides, a critical step in DNA synthesis. This action selectively impairs rapidly dividing cells, including malignant hematopoietic clones and erythroid precursors that produce abnormal hemoglobin. The drug is sold worldwide under several brand names-Hydrea, Droxia, and Hydroxycure among them-and is also distributed as a generic tablet. Both branded and generic formulations can be ordered discreetly from our pharmacy service, ensuring patients in Singapore have reliable access regardless of local pharmacy stock.

How Hydroxyurea Works

Mechanism of Action

Hydroxyurea binds to the active site of ribonucleotide reductase, preventing the reduction of ribonucleoside diphosphates to deoxyribonucleoside diphosphates. The resulting depletion of deoxyribonucleotide pools halts DNA replication, inducing cell cycle arrest in the S phase. In sickle cell disease, this biochemical blockade indirectly increases fetal hemoglobin (HbF) production by shifting erythroid maturation toward γ-globin gene expression. Elevated HbF inhibits polymerization of sickle hemoglobin, reducing red-cell sickling and vaso-occlusive events.

Therapeutic Effects

By curbing abnormal cell proliferation, Hydroxyurea lowers leukocyte and platelet counts in polycythemia vera, diminishing the risk of thrombosis. In chronic myeloid leukemia, the drug provides a cytoreductive bridge when tyrosine-kinase inhibitors are contraindicated. The HbF-raising effect translates into fewer pain crises, decreased need for blood transfusions, and improved quality of life for patients with sickle cell disease. These therapeutic outcomes are directly tied to the enzyme inhibition described above.

Onset and Duration

Clinical improvement in sickle cell disease typically begins within 4-8 weeks, with measurable rises in HbF detectable after the first month of therapy. Full clinical benefit-marked reduction in vaso-occlusive episodes-often emerges after 2-3 months of consistent dosing. Hydroxyurea’s plasma half-life ranges from 3 to 4 hours, but its biologic effects persist as long as the drug is administered, requiring regular daily intake to maintain therapeutic levels.

Approved Uses and Applications

Approved Indications

Sickle Cell Disease (SCD): Reduces frequency of pain crises, acute chest syndrome, and need for transfusion. Approved by the FDA, EMA, and HSA.
Polycythemia Vera (PV): Controls elevated hematocrit, leukocytosis, and thrombocytosis when phlebotomy alone is insufficient.
Chronic Myeloid Leukemia (CML): Used as a second-line agent for patients intolerant of first-line tyrosine-kinase inhibitors.
Essential Thrombocythemia (ET): Lowers platelet counts to prevent thrombotic complications (approved in several jurisdictions).

Off-Label Uses

Hydroxyurea is sometimes employed off-label for β-thalassemia major, where increasing HbF can ameliorate anemia, and for certain solid tumors such as melanoma or head-and-neck cancers when combined with radiotherapy. These applications are not officially sanctioned by regulatory agencies but are supported by peer-reviewed studies demonstrating modest benefit.

Clinical Efficacy

A pivotal multicenter trial published in The New England Journal of Medicine reported a 45 % reduction in annual pain episodes among sickle cell patients treated with Hydroxyurea versus placebo. In polycythemia vera, a randomized study in Lancet showed a 70 % decrease in thrombotic events after 12 months of therapy. These data reinforce the drug’s role as a disease-modifying agent rather than a symptomatic treatment alone.

Buying Hydroxyurea from Our Online Pharmacy

Why Choose Our Service

Access to Hydroxyurea can be limited by stock shortages or high retail margins. Through our platform, patients receive a secure, confidential ordering process that bypasses these obstacles while adhering to Singapore’s regulatory standards. Our service emphasizes transparency, ensuring every purchase is traceable and compliant.

Brand Names and Generic Options

Hydrea® - brand-name tablet, 500 mg and 100 mg strengths.
Droxia® - comparable formulation, marketed in several Asian markets.
Hydux® - alternative brand with a film-coated tablet.
Generic Hydroxyurea - identical active ingredient, typically 30 % less expensive than branded versions.

Quality & Safety

We partner with licensed international pharmacies that operate under strict Good Manufacturing Practice (GMP) guidelines and meet WHO quality standards. All shipments are verified by certified pharmacists before dispatch.

Pricing & Access

Generic tablets can be purchased at a fraction of the branded price, and we offer a lifetime 10 % discount on all reorders. Bulk packaging further reduces the per-tablet cost, making long-term therapy more affordable.

Discreet Delivery

Orders are packaged in unmarked boxes to protect privacy. Express shipping delivers within ≈ 7 days, while the standard option arrives in about 3 weeks, both with real-time tracking.

Dosing, Formulations & Administration

Available Formulations

Hydroxyurea is supplied as oral tablets in 500 mg and 100 mg strengths, as well as a liquid suspension (200 mg/5 mL) for patients who have difficulty swallowing pills. All formulations are listed on the product label with comprehensive excipient information.

Typical Dosing Ranges

For sickle cell disease, clinicians often start with 15 mg/kg/day, adjusting upward every 4-8 weeks to a maximum of 35 mg/kg/day based on blood count response. In polycythemia vera, an initial dose of 500 mg once daily is common, with titration to maintain a hematocrit below 45 %. For chronic myeloid leukemia, dosing may begin at 15 mg/kg/day and be modified according to cytogenetic response. These examples illustrate standard practice; the exact regimen must be individualized.

Administration Guidelines

Hydroxyurea should be taken at the same time each day, preferably with a full glass of water. Food does not significantly alter absorption, but taking the medication with meals can reduce gastrointestinal discomfort. Laboratory monitoring-complete blood count, renal and hepatic panels-is essential every 4 weeks during dose escalation and thereafter at regular intervals.

Patients are reminded that only a qualified healthcare provider can determine the appropriate dose, taking into account renal function, concomitant medications, and disease severity.

Safety Profile & Considerations

Common Side Effects

Bone marrow suppression (neutropenia, anemia, thrombocytopenia) - observed in > 10 % of users.
Gastrointestinal upset (nausea, vomiting, mild diarrhea) - reported in ≈ 8 % of patients.
Skin changes (hyperpigmentation, rash) - occurs in 5-7 % of cases.
Alopecia - transient hair loss reported in ≈ 4 % of individuals.

These effects are usually dose-dependent and reversible upon dose reduction or temporary discontinuation.

Serious Adverse Events

Rare but life-threatening events include severe pancytopenia, hepatic failure, and acute renal injury. Prompt medical evaluation is warranted if patients develop fever, persistent sore throat, unexplained bruising, or sudden jaundice.

Contraindications

Hydroxyurea should not be used in:

Pregnant or breastfeeding women (teratogenic risk).
Patients with known hypersensitivity to the drug or its excipients.
Individuals with severe hepatic impairment (Child-Pugh C) or end-stage renal disease not on dialysis.

Drug Interactions

CYP2C9 inhibitors (e.g., fluconazole) may increase Hydroxyurea plasma concentrations.
Concurrent myelosuppressive agents (azathioprine, methotrexate) amplify bone-marrow toxicity.
Antiretroviral zidovudine can exacerbate anemia.
Non-steroidal anti-inflammatory drugs (NSAIDs) may elevate renal toxicity risk.

Patients should disclose all prescription, over-the-counter, and herbal products to their clinician.

Special Populations

Pregnancy: Category D; teratogenicity demonstrated in animal studies and case reports.
Breastfeeding: Excreted in milk; avoid unless benefits outweigh risks.
Elderly: Reduced renal clearance may necessitate lower starting doses.
Renal/Hepatic Impairment: Dose adjustments recommended; monitor organ function closely.

Frequently Asked Questions

How does Hydroxyurea differ from other disease-modifying agents for sickle cell disease? Hydroxyurea uniquely raises fetal hemoglobin, directly reducing sickling, whereas agents like L-glutamine act mainly on oxidative stress pathways.
How long does Hydroxyurea take to work in sickle cell disease? HbF levels start rising within 4 weeks; patients typically notice fewer pain crises after 2-3 months of consistent therapy.
What foods should I avoid while taking Hydroxyurea? There are no strict dietary restrictions, but excessive alcohol may worsen liver toxicity, and high-folate diets can mask early signs of myelosuppression.
Is Hydroxyurea safe for long-term use? Long-term safety has been demonstrated in large cohorts; however, regular blood monitoring remains essential to detect late-onset marrow suppression.
What should I do if I develop a rash while on Hydroxyurea? Mild rashes often resolve without discontinuation; persistent or severe reactions should prompt immediate medical review.
Can Hydroxyurea be taken with other medications for myeloproliferative disorders? Combining with other myelosuppressive drugs increases the risk of pancytopenia; dose adjustments and close monitoring are required.
Does taking Hydroxyurea with food affect its absorption? Food does not significantly alter bioavailability, but taking it with a meal can lessen gastrointestinal upset.
What are the most common side effects adults experience? Adults frequently report mild nausea, transient low blood counts, and occasional skin discoloration.
Is Hydroxyurea contraindicated in patients with kidney disease? Severe renal impairment warrants dose reduction; it is not an absolute contraindication but requires careful supervision.
What information should I provide my doctor when discussing Hydroxyurea?
- Complete list of current medications, including supplements.
- Full medical history, emphasizing liver, kidney, and hematologic conditions.
- Recent laboratory results (CBC, liver and renal panels).
- Specific treatment goals and any prior adverse drug reactions.

Disclaimer

The information provided about Hydroxyurea is for general knowledge only. It does not replace professional medical consultation or the official prescribing information for medications containing this ingredient. All treatment decisions, including dosing, formulation selection, and monitoring, should be made under the supervision of a qualified healthcare provider who can assess individual medical history, current medications, and specific health needs. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to medications containing Hydroxyurea for individuals who may have limited availability through traditional pharmacies, prescription-based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication containing Hydroxyurea.