Hydrea (Hydroxyurea) Guide: Uses, Dosage, Side Effects & FAQs

21 September 2025

TL;DR

• Hydrea is the brand name for hydroxyurea, a chemo drug used for sickle cell disease and some cancers.
• Typical adult dose ranges from 15mg/kg to 30mg/kg daily, adjusted based on blood counts.
• Common side effects include low blood cells, nausea, skin changes, and hair loss.
• Take Hydrea exactly as prescribed; never skip doses or stop abruptly without a doctor’s OK.
• Call your doctor if you develop fever, unusual bruising, or severe stomach pain.

What is Hydrea and How Does It Work?

Hydrea is the trade name for the drug hydroxyurea. It belongs to a class called antimetabolites, which means it interferes with the way cells make DNA. By blocking DNA synthesis, the drug slows the growth of rapidly dividing cells-like cancer cells or the abnormal red blood cells seen in sickle cell disease.

In sickle cell disease, Hydroxyurea boosts the production of fetal hemoglobin (HbF). Higher HbF levels make red blood cells less likely to sickle, reducing painful crises and the need for blood transfusions. In oncology, the drug is most often used for chronic myelogenous leukemia (CML), certain head‑and‑neck cancers, and melanoma. Its dual role makes Hydrea a unique medication that straddles both hematology and oncology.

Because it targets cell division, Hydrea doesn’t discriminate between “bad” cells and healthy ones that also divide quickly, such as bone‑marrow cells that produce blood cells. This is why regular blood‑count monitoring is a must.

The drug is taken orally, usually in tablet form, and can be taken with or without food. Some brands offer a liquid formulation for patients who have trouble swallowing pills.

Dosage Guidelines, Administration Tips & Common Side Effects

Dosage is highly individualized. Doctors start with a low dose and adjust based on blood‑test results and how the patient tolerates the medication. Below is a typical dosing framework for the two most common indications.

Key administration tips:

• Take the same dose at the same time each day to keep blood levels steady.
• If you miss a dose, take it as soon as you remember-unless it’s almost time for the next dose. In that case, skip the missed one; don’t double up.
• Store tablets at room temperature, away from moisture and heat.
• Drink plenty of water with each dose to help the stomach tolerate the medication.

Because Hydrea suppresses bone‑marrow activity, the most common side effects are linked to low blood counts:

• Low white blood cells (neutropenia): Increased infection risk, fever, chills.
• Low platelets (thrombocytopenia): Easy bruising, nosebleeds, prolonged bleeding from cuts.
• Low red cells (anemia): Fatigue, shortness of breath, pale skin.

Other side effects you might notice include nausea, mild vomiting, loss of appetite, skin darkening (especially on the hands and face), and temporary hair thinning. Most of these are mild and improve as the body adjusts.

Serious, but rare, reactions can involve severe liver toxicity, lung inflammation (pneumonitis), or kidney problems. Prompt medical attention is crucial if you experience persistent abdominal pain, jaundice, or sudden swelling in the legs.

FAQs, Safety Precautions, and When to Call Your Doctor

Below are the questions patients most often ask after starting Hydrea. The answers aim to give you a clear picture of what to expect and how to stay safe.

1. Can I become pregnant while taking Hydrea? Hydroxyurea is classified as a pregnancy‑category D drug. It can cause birth defects, so women of child‑bearing age must use effective contraception. If you plan to become pregnant, discuss alternatives with your doctor.
2. Is it safe to drink alcohol? Small amounts of alcohol usually don’t interact directly with Hydrea, but both can irritate the stomach and depress bone‑marrow function. Limit intake and talk to your doctor if you notice increased nausea or fatigue.
3. Do I need a special diet? No strict diet is required, but maintain a balanced intake of iron‑rich foods (especially if you’re anemic). Avoid raw or undercooked meats if you’re neutropenic to reduce infection risk.
4. How often should I get blood work? Initially every 1-2 weeks, then every 4-8 weeks once stable. Your doctor will tailor the schedule based on how quickly your counts rebound.
5. What should I do if I develop a fever? Treat it as a medical emergency. Fever can signal infection when white‑cell counts are low. Call your clinic right away, even if the fever is mild.
6. Can I stop Hydrea on my own if I feel better? No. Stopping abruptly can cause a rebound of disease activity, especially in sickle cell patients. Any change in therapy must be approved by your physician.

**Safety checklist** before each dose:

• Check latest CBC results-make sure counts are within your doctor’s safe range.
• Confirm you’ve taken any prescribed supplements (folic acid is common with sickle cell patients).
• Review any new symptoms with your care team via a patient portal or phone call.

If you experience any of these red‑flag symptoms, contact your healthcare provider immediately:

• Fever ≥ 100.4°F (38°C) or chills.
• Unexplained bruising, nosebleeds, or gum bleeding.
• Severe nausea or vomiting lasting more than 24hours.
• Shortness of breath, chest pain, or new swelling in the legs.
• Yellowing of skin or eyes (possible liver issue).

Staying on top of labs, keeping open communication with your care team, and following the dosing schedule are the best ways to get the benefits of Hydrea while minimizing risks.