Common uses

This medication is used to treat several types of cancer and blood problems (e.g., squamous cell carcinoma, chronic myelogenous leukemia, sickle cell anemia). Hydroxyurea belongs to a class of drugs known as antineoplastics. It works by decreasing cancer cells and abnormal blood cells.
OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
This drug may also be used to treat polycythemia vera, thrombocythemia, and psoriasis.

Before using

Before taking hydroxyurea, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: low white blood cell count, low blood clotting cells (platelets), severely low red blood cells (anemia).
Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems, liver problems, radiation treatments, other chemotherapy, inflammation of the pancreas (pancreatitis), gout.
Because this medication can lower your body's ability to fight an infection, do not touch your eyes or the inside of your nose without first washing your hands. Do not have immunizations/vaccinations without the consent of your doctor, and avoid contact with people who have recently received oral polio vaccine or flu vaccine inhaled through the nose. If you have not had chicken pox, avoid people who have chicken pox or shingles or have been recently exposed to people with these illnesses. Use caution with sharp objects like safety razors or nail cutters, and avoid activities that might cause injury.
Since this medication may rarely cause serious liver disease, avoid alcoholic beverages while taking this medication.
Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, caution is advised when using this drug in the elderly since they may be more sensitive to the effects of the drug, especially decreased blood cell counts.
Hydroxyurea is not recommended for use during pregnancy. Consult your doctor for more details.
This drug passes into breast milk. Since this medication may cause severe side effects or cancer, avoid breastfeeding while taking this medication. Consult your doctor or pharmacist for more information.

Directions

Take this medication by mouth usually once daily or exactly as directed by your doctor. Unless your doctor instructs you otherwise, drink plenty of fluids while taking this medication. This helps your kidneys remove the drug from your body and may decrease some of the side effects. If you cannot swallow capsules, you may empty the contents into a glass of water and drink it immediately. If you open the capsule, be careful not to touch or inhale the drug powder.
Dosage is based on your body weight, medical condition, kidney function, and response to treatment. Your dose may be temporarily stopped by your doctor if your blood counts drop too low.
For caregivers: Wear disposable gloves when handling this medication or its container. If the powder inside the capsule spills, wipe it up with a damp paper towel and immediately place the towel in a closed plastic bag. Do not throw this plastic bag in the regular garbage, but dispose of it in special containers (ask your pharmacist for more information). Wash hands after handling the medication.
Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day. Do not change your dose or stop taking this medication unless instructed to do so by your doctor. Doing so could increase side effects or decrease the drug's effectiveness.
Tell your doctor immediately if your condition worsens.

Cautions

Hydroxyurea treatment may cause severe, sometimes fatal side effects (see also Side Effects section). Your doctor should be experienced in the use of this medication and will monitor you closely to decrease the risk of severe side effects.
This medication may also cause certain cancers (see also Side Effects section). It is not known if these cancers are due to the drug or the disease being treated. Consult your doctor for more information.

Possible side effects

Nausea, vomiting, loss of appetite, diarrhea, or constipation may occur. Less common side effects may also include drowsiness, dizziness, stomach irritation, tiredness, weakness, or headache. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
A common but serious side effect includes a severe decrease in blood cell counts. Your doctor will monitor your blood cell counts closely.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication may develop serious side effects, but with frequent visits to your doctor, this risk can be reduced.
Tell your doctor immediately if any of these unlikely but serious side effects occur: easy bruising/bleeding, black/bloody stools, blood in urine, burning with urination, signs of a serious infection (e.g., fever, severe chills, persistent sore throat, body/muscle aches), signs of low red blood cells (e.g., pale skin/lips/nails, shortness of breath with normal daily activities, decreased ability to exercise, easily tired, unusually fast heartbeat at rest), hair loss, mouth sores, skin problems (e.g., redness, ulcers, darkened/blackened skin), swelling, mental/mood changes (e.g., confusion, hallucinations).
Tell your doctor immediately if any of these rare but very serious side effects occur: lung problems (persistent cough, chest congestion, shortness of breath), signs of severe liver problems (e.g., persistent nausea/vomiting, abdominal pain, appetite loss, yellowing skin/eyes, brown urine, severe tiredness), seizures, severe stomach/back pain, tingling/burning/numbness of hands/feet/legs.
Other side effects may rarely occur with long-term daily use over several years. These may include skin darkening/thinning, nail thinning, purple skin spots, and other cancers (leukemia, skin cancer). Tell your doctor promptly if you notice any of these problems.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching, swelling, severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

If you take too much

Acute mucocutaneous toxicity has been reported in patients receiving hydroxyurea at a dosage several times the therapeutic dose. Soreness, violet erythema, edema on palms and foot soles followed by scaling of hands and feet, severe generalized hyperpigmentation of skin, and stomatitis have also been observed.

Additional information

Hydrea should not be used by anyone who:
is sensitive or allergic to Hydrea or any of the ingredients
has a very low white blood cell count
has a very low platelet count
has severe anemia
is breast-feeding

Drug interactions

This drug should not be used with the following medications because very serious interactions may occur: nalidixic acid, live virus vaccines (e.g., flu, measles, mumps, rubella, poliovirus, typhoid).
If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting hydroxyurea.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: didanosine, stavudine, interferon, probenecid.
Tell your doctor about other drugs you are taking that might also decrease blood cell counts (e.g., trimethoprim/sulfamethoxazole, zidovudine, other chemotherapy such as busulfan, among others).