Sounds like 'hye-DROX-ee-yoo-REE-ah'

Key points about hydroxyurea

  • Hydroxyurea is used to treat conditions such as some types of cancers and sickle-cell disease. 
  • Hydroxyurea is also called hydroxycarbamide or Hydrea.
  • Find out how to take it safely and the possible side effects.
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Hydroxyurea is used to treat some types of cancer by slowing the growth of some cells.

It's also used to treat some types of sickle cell disease by stopping red blood cells from changing to a sickle shape. It can help with symptoms of pain and reduce the number and severity of sickle cell crises, episodes of chest pain and the need for blood transfusions. It can also prevent or slow down damage to your organs. Read more about sickle cell disease.  

  • In Aotearoa New Zealand, hydroxyurea is available as 500 mg capsules.
  • The dose of hydroxyurea is different for different people depending on your body weight, the condition being treated, your response to treatment and other medicines or treatments you are taking. 
  • Your doctor may start you on a low dose and increase it slowly depending on your response.
  • Always take your hydroxyurea exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much hydroxyurea to take, how often to take it and any special instructions.

  • Timing: Swallow the capsule whole with a glass of water. You can take hydroxyurea with or without food. If hydroxyurea gives you nausea (makes you feel sick), try taking it with food. Most people take hydroxyurea once a day. Sometimes you may need to take a different number of capsules on certain days, or you may only need to take it once every third day.
  • Difficulty swallowing: If you cannot swallow the capsules whole, you can open the capsule and empty the powder into a glass of water. stir well, and drink it straight away. Wear gloves when handling the capsules and powder and wash your hands before and after. Make sure you clean up any spilt powder with a disposable towel or cloth. Do not handle the capsules, or powder if you are pregnant.
  • Folic acid: Your doctor may also prescribe a vitamin tablet called folic acid. Taking this vitamin can help reduce some side-effects of hydroxyurea.
  • Missed dose: If you forget to take your dose, take it as soon as you remember that day. But if it is nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.

Here are some things to know when you're taking hydroxyurea. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Taking other medicines: Hydroxyurea can interact with some other medicines, herbal supplements, and recreational drugs, so check with your doctor or pharmacist before starting hydroxyurea and before starting any new products.
  • Blood tests: You will need regular blood tests while taking hydroxyurea to check if it is causing problems with your liver, kidneys or blood.
  • Contraception: It's important that you don't get pregnant while you are taking hydroxyurea. Men should use contraception for one year after finishing treatment. If you are sexually active, talk to your doctor about contraception.
  • Protect your skin: Hydroxyurea can make your skin more sensitive to the sun, even on a cloudy day. This can cause a burning, tingling feeling on your skin when you are in the sun, or you may notice redness. When outside, protect your skin and eyes by using a good sunscreen (at least SPF30+) and wearing sunglasses, a sunhat and clothing that protects you from the sun. Do not use sunbeds.
  • Vaccines: Some vaccines can't be taken while on hydroxyurea treatment and for 6 months after stopping. Talk to your doctor about your options.

Like all medicines, hydroxyurea can cause side effects, but not everyone gets them. Often side effects improve as your body gets used to the new medicine. 

Side effects What should I do?
  • Sore throat or mouth
  • High temperature (fever) 
  • Chills
  • Hydroxyurea can increase your risk of getting an infection.
  • Tell your doctor immediately or ring Healthline 0800 611 116.
  • Unusual bruising or bleeding
  • Signs of bleeding problems such as black, tarry stools; blood in urine; pinpoint red spots on skin, extensive bruising
  • Hydroxyurea can lower your platelets and increase your risk of bleeding and bruising.
  • Avoid tasks where you may bruise or get injured.
  • Tell your doctor immediately or ring Healthline 0800 611 116.
  • Feeling sick (nausea)
  • Loss of appetite
  • Runny poos (diarrhoea)
  • Constipation
  • Tummy pain
  • Indigestion
  • Change in nails
  • Tiredness and drowsiness
  • These are quite common.
  • Tell your doctor if they bother you.
  • If you're feeling drowsy, don't drive or operate tools or machinery. Limit or avoid alcohol.
  • Thinning of hair or hair loss 
  • Take care with use of hair spray, bleaches, dyes and perms.
  • Your hair will grow back once you stop treatment with hydroxyurea. The colour and texture may change.
  • Use a gentle shampoo and soft brush.
For more information on side effects, see the consumer information leaflet here.

Did you know that you can report a medicine side effect to the Centre for Adverse Reactions Monitoring (CARM)? Report a side effect to a product.(external link)

The following links have more information on hydroxyurea. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Hydoxycarbamide Consumer Information, NZ
Hydroxycarbamide(external link) PatientInfo, UK
Hydroxycarbamide for cancer(external link) Macmillan, UK
Hydroxyurea(external link) DermNet, NZ
Hydroxycarbamide for psoriasis(external link) British Association of Dermatologists, UK


  1. Hydroxycarbamide (hydroxyurea)(external link) NZ Formulary
  2. Hydroxycarbamide (Devatis)(external link) Medsafe, NZ

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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