Droxia, Siklos
Hydroxyurea (also known by its brand names Droxia and Siklos) is an antimetabolite. It's used to lower the number of painful crises and need for blood transfusions in adults and children with sickle cell anemia. Droxia (hydroxyurea) is taken by mouth, typically once daily. Some of the more common side effects of this medication includes lower blood cell counts and higher risk for infections.
What is Droxia (hydroxyurea)?
What is Droxia (hydroxyurea) used for?
- To lower the number of pain crises and need for blood transfusions in people with sickle cell anemia
How Droxia (hydroxyurea) works
Droxia (hydroxyurea) is an antimetabolite. The way it works to treat sickle cell anemia isn't fully clear. But it's thought to make your red blood cells bigger by raising the amount of hemoglobin F (a protein that carries oxygen) and water in your red blood cells. When your blood cells are larger and more round, they're less likely to turn into a sickle shape and cause problems.
Drug facts
Side effects of Droxia (hydroxyurea)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
Children:
- Infections (40%)
- Lower blood cell counts (13%)
- Stomach problems (13%)
- Fever (8%)
- Headache (7%)
- Low vitamin D levels (6%)
Adults:
- Infections (43%)
- Headache (20%)
- Dry skin (12%)
- Lower blood cell counts (10%)
- Joint pain (9%)
- Weakness (9%)
- Dizziness (9%)
- Fever (8%)
- Skin wounds (7%)
- Nausea (6%)
- Cough (6%)
Less Common Side Effects
- Weight gain
- Hair loss
- Swelling
- Skin reaction
Side effects listed are reported from people taking Siklos. The side effects you experience might differ if you take Droxia.
Droxia (hydroxyurea) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Serious infection: fever, cough, difficulty breathing, diarrhea, weakness, sweating, chills, scaly or burning skin, confusion, changes in personality, changes in vision, headache, stiff neck, light sensitivity, seizures
The following Droxia (hydroxyurea) side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
Black, tarry stools
blood in the urine or stools
chills
hoarseness
lower back or side pain
painful or difficult urination
pale skin
pinpoint red spots on the skin
ulcers, sores, or white spots in the mouth
unusual bleeding or bruising
unusual tiredness or weakness
Less common
Blackening of the fingernails and toenails
troubled breathing with exertion
Rare
Confusion
dizziness
headache
joint pain
seeing, hearing, or feeling things that are not there
seizures
swelling of the feet or lower legs
Incidence not known
Bleeding under the skin
blisters on the skin
bluish or pale color on the skin of the fingers or toes
coldness of the fingers or toes
crater-like lesions on the skin
drowsiness
fast heartbeat
irritation
itching, pain, redness, or swelling on the leg
joint stiffness or swelling
loss of appetite
muscle spasms (tetany) or twitching seizures
numbness or tingling of the fingers or toes
pain in the fingers or toes
sore on the leg
swelling of the eyelids, face, lips, hands, or feet
tightness in the chest
trembling
troubled breathing or swallowing
vomiting
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Get your GoodRx coupon
Pros and cons of Droxia (hydroxyurea)
Pros
- Taken by mouth
- Available as a tablet or capsule with once-daily dosing
- Siklos can be used in children 2 years of age and older
- Siklos tablets can be dissolved in water for people who have trouble swallowing pills
Cons
- Can't touch with your bare hands because it can damage your skin
- Requires regular blood tests (typically every 2 weeks) for monitoring during treatment
- Risk of serious infections
- Not safe during pregnancy
Pharmacist tips for Droxia (hydroxyurea)
- Droxia (hydroxyurea) must be handled safely because it's toxic. Always wash your hands with soap and water before and after touching the Droxia (hydroxyurea) bottle or medication to prevent others from being exposed to it and causing side effects. If you're giving the medication to someone else, wear gloves when handling the bottle or medication for this reason.
- If you accidentally touch Droxia (hydroxyurea) to your skin, wash the affected area right away thoroughly with soap and water. If you get it in your eyes, wash them with water or an eyewash for at least 15 minutes.
- If you accidentally spill powder from a broken Siklos tablet or damaged Droxia capsule, wear gloves and wipe it up with a damp towel and throw it away in a closed container (e.g., plastic bag) to prevent exposing other people or pets to it. Use a detergent solution followed by clean water to clean the spill area at least 3 times.
- You can dissolve Siklos tablets in a small amount of water in a teaspoon and swallow right away if you or your child have trouble swallowing them. But if you're using Droxia capsules, don't open, crush, or chew capsules. Instead, you must swallow the capsules whole.
- Make sure to get your blood tests done on time (typically once every 2 weeks) so your provider can monitor your blood cell counts during your treatment with Droxia (hydroxyurea).
- If you go out into the sun, wear protective clothing and sunscreen to lower your risk of sun damage and skin cancer from Droxia (hydroxyurea).
- Speak with your provider before getting any vaccines, since some vaccines (e.g., live vaccines) might lead to a severe infection while you're taking Droxia (hydroxyurea).
- Droxia (hydroxyurea) isn't recommended if you're breastfeeding because it can get into breast milk and potentially harm your baby. It also isn't recommended during pregnancy. If you or your partner are able to become pregnant, you'll need to use birth control during treatment with Droxia (hydroxyurea). You'll also need to continue taking birth control for at least 6 months (for females taking either Droxia or Siklos and males taking Siklos) or 1 year (males taking Droxia) after stopping the medication.
- Store broken Siklos tablets in the medication bottle and use them within 3 months. Keep this medication in a safe place out of reach of visitors, children, and pets. If someone you know accidentally swallows it, get medical help right away.
Common questions about Droxia (hydroxyurea)
Droxia (hydroxyurea) is toxic to cells, including skin cells. So if you touch it, it can irritate or damage your skin. Make sure to always wear gloves when handling the medication pills or medication bottle and wash your hands with soap and water afterwards. If you do accidentally touch Droxia (hydroxyurea), make sure to wash the affected area well with soap and water. If you accidentally get the medication into your eyes, you'll need to flush your eyes with water for at least 15 minutes.
Stopping Droxia (hydroxyurea) could raise your risk for sickle cell crises as well as the need for blood transfusions. If you want to stop taking Droxia (hydroxyurea), it's best to talk to your provider first so they can come up with a plan for you.
There isn't a set amount of time you'll need to take Droxia (hydroxyurea) because it doesn't cure sickle cell anemia. Your provider will likely have you take Droxia (hydroxyurea) as long as it's helping avoid pain crises and blood transfusions and you're not having any significant side effects. One study showed Droxia (hydroxyurea) worked well and was safe for people with sickle cell anemia who took the medication for over 17 years.
Droxia (hydroxyurea) can potentially cause weight gain, but it's rare. In clinical studies, only 2% of children and 4% of adults taking Siklos reported weight gain. But, Droxia (hydroxyurea) can cause nausea, vomiting, constipation, or diarrhea as side effects, which can lead to weight loss if it affects your appetite. It's important to eat a nourishing diet and stay hydrated as much as possible. Talk with your provider if you're having trouble eating or drinking or if you notice unusual weight changes while you're taking this medication.
Droxia and Siklos are two different brand names that contain the same active medication, hydroxyurea. The main difference is that Droxia is available as capsules and can only treat adults. But Siklos is available as tablets and can be taken by both adults and children ages 2 years of age and older. Speak with your provider about the best treatment option for your condition.
Chemotherapy is a type of treatment that kills fast-growing cells and is typically used to treat cancer. While Droxia and Siklos are only FDA-approved to treat sickle cell anemia, hydroxyurea is considered a type of chemotherapy. This is because one effect hydroxyurea has on cells is interfering with the way they make their genetic material, which prevents cells from growing and dividing. In fact, one brand of hydroxyurea called Hydrea, is used to treat cancer.
No, Droxia (hydroxyurea) isn't a blood thinner (or anticoagulant); it's known as an antimetabolite. But, Droxia (hydroxyurea) can potentially raise your risk of bleeding because it lowers platelet levels as a side effect. Your provider will monitor your blood counts during treatment to make sure they don't get too low. Seek medical help if you notice unusual bleeding or bleeding that doesn't stop for a long time.
How to save using GoodRx
Risks and warnings for Droxia (hydroxyurea)
Droxia (hydroxyurea) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Low blood cell counts
- Risk factors: Taking high doses of Droxia (hydroxyurea)
Droxia (hydroxyurea) can lower the numbers of red blood cells (RBCs), white blood cells (WBCs), and platelets in the body. This can raise the risk for bleeding, anemia, and infections. Your provider will order blood draws to check your blood cell counts.
Let your provider know if you have possible symptoms of low blood cell counts, such as bleeding (small, flat red spots under the skin; bloody urine or stool; easy bleeding or bruising) or anemia (feeling tired, headache, pale skin, fast heart rate, trouble breathing). Also tell your provider right away if you have an infection with fever, chills, tiredness, cough, body aches, and runny nose symptoms.
Possible risk of cancer
- Risk factors: Taking Droxia (hydroxyurea) for a long time
People taking Droxia (hydroxyurea) might be at higher risk for cancer, like lymphomas and skin cancer. The risk might be higher for people who take Droxia (hydroxyurea) over longer periods of time. Your provider will check your blood cell counts regularly during treatment to check for signs of blood cancers.
To help monitor for skin cancer specifically, make sure you schedule yearly screenings for skin cancer and tell your provider if you notice changes to your skin. To lower your risk for skin cancer, wear protective clothing and use sunscreen when you go outside and avoid UV light (e.g., tanning beds).
Harm to unborn babies
- Risk factors: Pregnancy
Droxia (hydroxyurea) might cause harm to unborn babies when taken during pregnancy. In animal studies, it caused harm to unborn babies of pregnant mothers, including development problems and death. Make sure to use birth control during treatment and for at least 6 months (for females taking either Droxia or Siklos, and for males taking Siklos) or 1 year (for males taking Droxia) after stopping to prevent harm to unborn babies. If you or your partner becomes pregnant while you're taking Droxia (hydroxyurea), contact your provider right away.
Blood vessel damage
- Risk factors: History of blood cancer | Taking interferon medication
Blood vessel damage, including leg ulcers, has occurred in people with blood cancers who also took Droxia (hydroxyurea). If you develop an open sore or wounds anywhere on your body while taking the medication, contact your provider. They might need to lower your dose or have you stop taking it until your ulcer heals.
Pancreas, liver, or nerve damage
- Risk factors: Taking HIV medications
Pancreatitis (inflammation of the pancreas), liver damage, and nerve damage have been reported in people who took Droxia (hydroxyurea) while also taking antiretroviral medications (commonly used to treat HIV infection). If you experience stomach pain, nausea, vomiting, tingling in your arms, legs, hands, or feet, or yellowing of the whites of your eyes or skin, tell your provider so you can be checked for these problems.
Lung problems
In people taking hydroxyurea (Hydrea) for cancer, the medication has caused lung damage that was sometimes deadly. This hasn't been seen in people taking Droxia (hydroxyurea) for sickle cell anemia, but if you experience fever, chest pain, cough, shortness of breath, or other signs of lung damage, contact your provider.
Droxia (hydroxyurea) dosage
Capsule| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 200mg | 30 capsules | $40.87 | $1.36 |
| 300mg | 60 capsules | $58.48 | $0.97 |
| 400mg | 30 capsules | $42.45 | $1.42 |
Typical dosage for Droxia (hydroxyurea)
The dose is based on your body weight and if you have kidney problems. Your provider will monitor you and adjust your dose based on your blood cell counts.
Droxia (hydroxyurea) capsules:
- Adults: The typical starting dose is 15 mg/kg by mouth once daily. The maximum dose is 35 mg/kg per day.
- Adults: The typical starting dose is 15 mg/kg by mouth once daily. The maximum dose is 35 mg/kg per day.
- Children 2 years and older: The typical starting dose is 20 mg/kg by mouth once daily. The maximum dose is 35 mg/kg per day.
Interactions between Droxia (hydroxyurea) and other drugs
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Measles Virus Vaccine, Live
- Mumps Virus Vaccine, Live
- Rotavirus Vaccine, Live
- Rubella Virus Vaccine, Live
- Varicella Virus Vaccine, Live
- Zoster Vaccine, Live
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Adenovirus Vaccine
- Bacillus of Calmette and Guerin Vaccine, Live
- Cholera Vaccine, Live
- Dengue Tetravalent Vaccine, Live
- Didanosine
- Influenza Virus Vaccine, Live
- Poliovirus Vaccine, Live
- Smallpox Vaccine
- Stavudine
- Typhoid Vaccine, Live
- Yellow Fever Vaccine
How much does Droxia (hydroxyurea) cost?
$40.87
What are alternatives to Droxia (hydroxyurea)?
News about Droxia (hydroxyurea)
Droxia (hydroxyurea) images
