Taking hydroxycarbamide
Hydroxycarbamide for sickle cell disease
Your haematologist or clinical nurse specialist will prescribe hydroxycarbamide in clinic.
Some GPs may be able to take over the prescribing, once it has been started by your specialist team. Please discuss this with your haematology team and your GP.
How to take it
Hydroxycarbamide will be prescribed as capsules that are taken orally (by mouth). Each capsule contains 500mg of hydroxycarbamide.
Hydroxycarbamide can be taken with or without food.
Doses (amounts) for adults with sickle cell range from 1 to 4 capsules each day.
You'll usually start at a low dose of 1 capsule each day. Your doctor will check your blood regularly and may slowly increase the dose. The aim is to find the highest dose that is safe for your bone marrow and still works well.
Important
Do not take more than your doctor has prescribed. If you take more than the amount prescribed this may stop your bone marrow working normally. This can cause serious health problems.
For hydroxycarbamide to work properly you have to take it every day as directed by your haematologist. It will not work if you only take it when you are ill or in pain.
If you forget a dose
If you forget to take a dose, take your normal dose the next day. Do not take a double dose.
Tell your haematologist the next time you go to clinic how many times you have missed a dose.
If you are sick (vomit) just after taking your capsules, do not take an extra capsule. Take your normal dose the next day.
Length of treatment
You should continue to take hydroxycarbamide as advised, unless your haematologist or another doctor tells you not to. If you want to stop taking it please talk to your haematologist first.
If there has been no improvement to your condition, and you have been taking the correct dose for several months, your doctors will usually advise you to stop taking it.
Taking hydroxycarbamide with other medicines
You should tell your doctor about any other medicines you are currently taking, or planning to take, before you start taking hydroxycarbamide. This includes any medicines you buy from a pharmacy or shop, vitamins, and any herbal or homoeopathic remedies.
The dose may need to be changed because of your other medicines.
Once you are taking hydroxycarbamide, you should also tell your doctor or pharmacists if you start taking any new medicines. This includes medicines you buy from a pharmacy or shop.
What to do if there is a problem
If you become unwell while taking the medicine, or have any concerns, you can contact the sickle cell team during office hours. Your blood count may have dropped so we will need to monitor you closely.
Outside of these hours, visit NHS 111 online, or call 111.
Go to your nearest emergency department (A&E) if:
- you have severe pain, or pain that is not responding to your usual painkillers
- you have pain which is different to your usual sickle pain
- you have a high temperature (fever)
- you have shortness of breath, especially with chest pain
- you have any other symptoms that you're concerned about
Storing hydroxycarbamide
- Store the capsules in a closed container at room temperature away from heat, moisture and direct light.
- Keep the capsules out of the reach of children. They can be harmful if children swallow them.
Never share your medicine with anyone.
If you stop taking hydroxycarbamide for any reason, please return your capsules to the pharmacy. Do not throw them in the bin or flush them down the toilet.
Resource number: 1979/VER5
Last reviewed: November 2025
Next review due: November 2028
