Hydrea (hydroxycarbamide) is a prescription drug that’s used to treat certain types of cancer. This drug can interact with vaccines and some other medications. For example, Hydrea can interact with HIV drugs.
Hydrea is used in adults to treat certain types of:
- chronic myeloid leukemia
- squamous cell carcinomas of the head and neck
An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.
Keep reading to learn about Hydrea’s possible interactions. And for more information about Hydrea, including details about its uses, see this article.
Before you start taking Hydrea, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Hydrea interacts with herbs or vitamins and supplements, see the “Are there other interactions with Hydrea?” section below.)
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The table below lists drugs that may interact with Hydrea. Keep in mind that this table does not include all drugs that may interact with Hydrea. For more information about some of these interactions, see the “Drug interactions explained” section below.
| Drug group or drug name | Drug examples | What can happen |
| antiretrovirals (HIV drugs) | • efavirenz (Sustiva) • ritonavir (Norvir) • zidovudine (Retrovir) | can cause liver, pancreas, and nerve side effects |
| chemotherapy drugs | • cisplatin • cytarabine • daunorubicin | can cause low blood cell counts |
Certain health conditions or other factors could raise your risk of harm if you take Hydrea. In such cases, your doctor may not prescribe Hydrea for you. These are known as contraindications. Allergic reaction is the only contraindication of Hydrea.
If you’ve had an allergic reaction: If you’ve had an allergic reaction to Hydrea or any of its ingredients, your doctor likely won’t prescribe Hydrea for you. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better options for you.
Hydrea is not known to interact with alcohol. But Hydrea and alcohol can cause some similar side effects, such as dizziness, drowsiness, and headache. So you may be more likely to experience these side effects if you drink alcohol during your Hydrea treatment.
Hydrea can also cause mouth sores. If you have this side effect with Hydrea, drinking alcohol could be painful.
If you have questions about consuming alcohol while taking Hydrea, talk with your doctor or pharmacist.
Learn more about certain drug interactions that can occur with Hydrea.
Interaction with antiretrovirals
Hydrea can interact with antiretrovirals, which are drugs used to treat HIV.
Examples of antiretroviral medications include:
- efavirenz (Sustiva)
- ritonavir (Norvir)
- zidovudine (Retrovir)
What could happen
Taking Hydrea with antiretrovirals can raise your risk of certain side effects, such as pancreatitis (swelling in the pancreas), liver damage, and nerve damage.
What you can do
If you take Hydrea with antiretrovirals, your doctor will likely monitor you closely for side effects. For example, they may order frequent tests to check your liver function.
If you take Hydrea and antiretrovirals together, tell your doctor right away if you have symptoms of pancreatitis or liver problems. These may include nausea, vomiting, abdominal (belly) pain, fever, and dark urine. Also tell your doctor right away if you have symptoms of nerve damage. These may include tingling feelings, burning pain, and numbness.
If you have questions about taking Hydrea with antiretrovirals, talk with your doctor or pharmacist.
Interaction with chemotherapy
Hydrea is a chemotherapy drug. It can interact with other chemotherapy drugs, which are used to treat cancer.
Examples of chemotherapy medications:
- cisplatin
- cytarabine
- daunorubicin
What could happen
Hydrea and other chemotherapy drugs can both cause low blood cell counts. These include low levels of white blood cells (cells that fight infection), red blood cells (cells that carry oxygen), and platelets (cells that help blood to clot). So taking these drugs together can raise your risk of problems with your blood cells.
What you can do
If your doctor prescribes Hydrea with other chemotherapy drugs, they’ll usually order frequent blood tests to check your blood cell counts.
If you take Hydrea with other chemotherapy, tell your doctor right away if you have symptoms of low blood cell counts. These can include fever or other signs of infection, feeling short of breath or unusually tired, and unusual bruising or bleeding.
If your blood cell counts drop too low, your doctor may pause your treatment with Hydrea, other chemotherapy, or both, until your blood cells recover.
Hydrea may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below does not include all other possible interactions with Hydrea.
Does Hydrea interact with supplements?
Before you start taking Hydrea, talk with your doctor and pharmacist about any herbs or vitamins and supplements you take. Sharing this information with them may help you avoid possible interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Hydrea and herbs
There are currently no reports of Hydrea interacting with herbs. But this doesn’t mean that interactions with herbs won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while taking Hydrea.
Hydrea and vitamins
There are currently no reports of Hydrea interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while taking Hydrea.
Does Hydrea interact with food?
There are currently no reports of Hydrea interacting with food. If you have questions about eating certain foods during your treatment with Hydrea, talk with your doctor.
Does Hydrea interact with vaccines?
Yes, it does. If you receive a vaccine while taking Hydrea, your immune system is weakened and may not respond to the vaccine as well as it should.
Before you start taking Hydrea, talk with your doctor about your vaccination history. Your doctor may recommend getting up to date with certain vaccines before you start treatment with Hydrea.
You should not receive live vaccines* during your Hydrea treatment. This is because getting a live vaccine while you’re taking Hydrea increases your risk of infection. Examples of live vaccines include measles, mumps, rubella (MMR), rotavirus, chickenpox, and the nasal spray flu vaccine. If you need to receive a vaccine, talk with your doctor first to make sure it’s safe.
* Live vaccines contain weakened versions of the bacteria or virus that they’re meant to protect against.
Does Hydrea interact with lab tests?
Hydrea can interact with lab tests used to check the levels of uric acid, urea, and lactic acid in your blood. The drug can make the test results show that your blood levels of these substances are higher than they really are.
If you have blood tests to check your uric acid, urea, or lactic acid levels, make sure the healthcare professional ordering the test knows that you’re taking Hydrea.
Hydrea can also interact with certain continuous glucose monitoring (CGM) devices, which some people with diabetes use to monitor their blood sugar levels. The drug can make certain CGM devices show that your blood sugar levels are higher than they really are.
If you use a CGM system, talk with your doctor before you start taking Hydrea. Your doctor may recommend using a different method to monitor your blood sugar during Hydrea treatment.
If you have questions about having lab tests during your treatment with Hydrea, talk with the healthcare professional ordering the test.
Does Hydrea interact with cannabis or CBD?There are currently no reports of Hydrea interacting with cannabis (commonly called marijuana) or cannabis products such as cannabidiol (CBD). But as with any drug or supplement, talk with your doctor before using cannabis with Hydrea.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions or other health factors may raise the risk of interactions with Hydrea. Before taking Hydrea, talk with your doctor about your health history. They’ll determine whether Hydrea is right for you.
Health conditions or other factors that might interact with Hydrea include:
Low blood cell counts. Hydrea can lower the levels of red blood cells, white blood cells, and platelets in your blood. If you already have low blood cell counts, your doctor may prescribe treatment to correct this before you start taking Hydrea.
Past radiation therapy. If you’ve had past radiation therapy, Hydrea can cause a flare-up of any radiation dermatitis you may have had with the radiation therapy. Talk with your doctor about whether Hydrea is right for you.
Kidney problems. Hydrea is cleared from your body by your kidneys. If you have kidney problems, Hydrea can build up in your body. This can raise your risk of side effects from Hydrea. For this reason, your doctor will likely prescribe a dosage of Hydrea that’s lower than usual.
Pregnancy. Hydrea is not safe to take during pregnancy. The drug can cause fetal harm. If you’re pregnant or planning a pregnancy, talk with your doctor about your treatment options.
If you’re able to become pregnant, you should use birth control while taking Hydrea and for at least 6 months after your last dose. If you’re male and have a sexual partner who’s able to become pregnant, you should use a barrier method, such as condoms, while taking Hydrea and for at least 1 year after your last dose.
Breastfeeding. You should not breastfeed while taking Hydrea. The drug passes into breast milk and can cause serious side effects in a child who’s breastfed. If you’re breastfeeding or planning to breastfeed, talk with your doctor about your options.
Allergic reaction. If you’ve had an allergic reaction to Hydrea or any of its ingredients, your doctor will likely not prescribe Hydrea. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Taking certain steps can help you avoid interactions with Hydrea. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- whether you drink alcohol or use cannabis
- other medications you take, as well as any vitamins, supplements, and herbs (they can also help you fill out a
medication list ) - what to do if you start taking a new drug during your Hydrea treatment
It’s also important to understand Hydrea’s
If you have trouble reading or understanding this information, your doctor or pharmacist can help.
Taking Hydrea exactly as prescribed can also help prevent interactions.
If you still have questions about Hydrea and its possible interactions, talk with your doctor.
Questions you may want to ask your doctor include:
- Do I need to have any vaccinations before starting Hydrea?
- Do I need to check before taking over-the-counter medications with Hydrea?
- Can I take echinacea to boost my immune system while taking Hydrea?
To learn more about Hydrea, see these articles:
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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.