Jul 25, 2022

Generic name: hydroxyurea [ hye-DROX-ee-yoo-REE-a ]
Brand names: Droxia, Hydrea, Mylocel, Siklos
Dosage forms: oral capsule (200 mg; 300 mg; 400 mg; 500 mg); oral tablet (100 mg; 1000 mg)
Drug class:  Antimetabolites

What is hydroxyurea?

Hydroxyurea is used to treat  chronic myeloid leukemia , ovarian cancer, and certain types of skin cancer (squamous cell cancer of the head and neck).

Hydroxyurea is also used to reduce pain episodes and the need for blood transfusions in people with sickle cell anemia. Hydroxyurea will not cure sickle cell anemia.

Hydroxyurea may also be used for purposes not listed in this medication guide.


Both men and women using hydroxyurea should use birth control to prevent pregnancy. The use of hydroxyurea by either parent may cause birth defects.

Using hydroxyurea may increase your risk of developing other types of cancer, such as  leukemia  or skin cancer. Wear protective clothing and use sunscreen when you are outdoors.

Hydroxyurea can weaken your immune system. Call your doctor at once if you have a fever, chills, body aches, extreme tiredness, shortness of breath, bruising, or unusual bleeding.

Before taking this medicine

You should not use hydroxyurea if you are allergic to it.

Tell your doctor if you have ever had:

  • kidney disease (or if you are on dialysis);
  • liver disease ;
  • a wound or ulcer on your leg;
  • HIV  or AIDS (especially if you take antiviral medicine);
  • high levels of uric acid in your blood; or
  • treatment with an interferon,  chemotherapy , or radiation.

Using hydroxyurea may increase your risk of developing other types cancer or leukemia. Talk with your doctor about your specific risk.

Hydroxyurea can harm an unborn baby. Both men and women using this medicine should use birth control to prevent pregnancy. The use of this medicine by either parent may cause birth defects.

  • If you are a woman, keep using  birth control  for at least 6 months after your last dose of hydroxyurea.
  • If you are a man, keep using birth control for at least 1 year after your last dose (6 months if you took Siklos).
  • Tell your doctor right away if a pregnancy occurs while either the mother or the father is using this medicine.

This medicine may affect fertility (ability to have children) in men. However, it is important to use birth control because hydroxyurea may harm the baby if a pregnancy does occur.

You should not breastfeed while you are taking hydroxyurea.

Older adults may be more sensitive to the effects of this medicine.

How should I take hydroxyurea?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Hydroxyurea is usually taken once per day at the same time of day, with or without food. Swallow the pill whole with a glass of water.

Wash your hands before and after you handle hydroxyurea or the bottle that contains the pills. For best protection, wear disposable gloves when handling the pills.

Do not open the hydroxyurea capsule or crush or chew a tablet. Do not use a broken pill. The medicine from a crushed or broken pill can be dangerous if it gets in your eyes, mouth, or nose, or on your skin. If this occurs, wash your skin with soap and water or rinse your eyes with water.

If any powder from a broken pill is spilled, wipe it up at once with a damp paper towel and throw the towel away in a sealed plastic bag where children and pets cannot get to it.

Your doctor may also want you to take a  folic acid  supplement. Follow dosing instructions very carefully.

Hydroxyurea can lower your blood cell counts. Your blood will need to be tested often. Your cancer treatments may be delayed based on the results.

This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using hydroxyurea.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

Detailed Hydroxyurea dosage information

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Get your prescription refilled before you run out of medicine completely.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include drowsiness, mouth sores, and swelling with pain and purple discoloration in your hands and feet.

What should I avoid while taking hydroxyurea?

Using hydroxyurea may increase your risk of developing skin cancer. Avoid exposure to sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Do not receive a “live” vaccine while using hydroxyurea, or you could develop a serious infection. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster ( shingles ), and nasal flu ( influenza ) vaccine.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Do not handle hydroxyurea pills or the medicine bottle without skin protection (disposable gloves).

Hydroxyurea side effects

Get emergency medical help if you have signs of an allergic reaction:  hives ; difficulty breathing; swelling of your face, lips, tongue, or throat.

Hydroxyurea may cause serious side effects. Call your doctor at once if you have:

  • numbness , tingling, or burning pain in your hands or feet;
  • skin numbness or purple discoloration;
  • skin ulcers or open sores;
  • sudden chest pain, wheezing, dry cough, feeling short of breath;
  • low blood cell counts–fever, chills, tiredness, mouth sores, easy bruising, unusual bleeding, pale skin,  cold hands  and feet, feeling light-headed; or
  • signs of liver or pancreas problems–loss of appetite, upper stomach pain (that may spread to your back),  nausea  or  vomiting ,  fast heart rate , dark urine,  jaundice  (yellowing of the skin or eyes).

Common side effects of hydroxyurea may include:

  • loss of appetite, nausea;
  • constipation ,  diarrhea ;
  • low blood cell counts;
  • bleeding; or
  • mouth sores.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Hydroxyurea side effects  (more detail)

What other drugs will affect hydroxyurea?

Some medicines can increase your risk of serious side effects while taking hydroxyurea. Tell your doctor if you are also using antiviral medicine or an interferon.

Other drugs may affect hydroxyurea, including prescription and over-the-counter medicines,  vitamins , and  herbal products . Tell your doctor about all your current medicines and any medicine you start or stop using.

source :: https://www.drugs.com/mtm/hydroxyurea.html