Patient Handout: Hydroxyurea

What is Hydroxyurea?

Hydroxyurea is a medication commonly used to treat certain types of cancer and blood disorders. It works by slowing the growth of abnormal cells in the body, such as cancer cells, or by modifying the production of certain blood cells. Hydroxyurea is most often used to treat:

• Chronic myelogenous leukemia (CML), a type of blood cancer
• Sickle cell disease, to reduce the frequency of painful episodes
• Polycythemia vera, a blood disorder where the bone marrow makes too many red blood cells
• Essential thrombocythemia, a condition where the body produces too many platelets

How Does Hydroxyurea Work?

Hydroxyurea works by interfering with the production of DNA in cells, which slows down or stops the growth of abnormal cells. In cancer treatment, this can help control the growth of cancer cells, while in blood disorders, it can help normalize blood cell production.

How Should I Take Hydroxyurea?

• Dosage: The dosage will be determined by your doctor based on your condition, weight, and other individual factors.
• Administration: Hydroxyurea is usually taken as an oral tablet. It is important to take the medication exactly as prescribed by your doctor.
• How to take: Swallow the tablet whole with water. You can take Hydroxyurea with or without food. If you are prescribed a liquid form of Hydroxyurea, follow your doctor’s instructions on how to measure and take the dose.
• Missed dose: If you miss a dose, take it as soon as you remember unless it is almost time for your next dose. Do not double the dose to make up for a missed one.

Possible Side Effects

Like all medications, Hydroxyurea can cause side effects. Not everyone experiences them, but it is important to be aware of potential side effects:

• Common side effects:
  • Nausea and vomiting
  • Fatigue (feeling tired)
  • Loss of appetite
  • Diarrhea or constipation
  • Skin rashes or changes in skin color
  • Mouth sores
• Serious side effects (contact your doctor immediately if you experience any of these):
  • Low blood counts: Hydroxyurea can lower the number of red blood cells, white blood cells, and platelets, leading to anemia, infections, or bleeding. Symptoms include unusual tiredness, fever, easy bruising, or bleeding.
  • Liver problems: Symptoms of liver issues may include yellowing of the skin or eyes (jaundice), dark urine, or abdominal pain.
  • Kidney problems: Signs of kidney issues include changes in urination or swelling in the legs or ankles.
  • Severe allergic reactions: Swelling of the face, lips, throat, or difficulty breathing.

Precautions

Before starting Hydroxyurea, tell your doctor if you have:

• Liver or kidney disease: Your doctor may need to adjust the dosage or monitor your function closely.
• Bone marrow problems: Hydroxyurea affects bone marrow and can lower your blood cell count, so your doctor will monitor your blood regularly.
• Pregnancy or breastfeeding: Hydroxyurea may harm an unborn baby, so it should not be taken during pregnancy unless absolutely necessary. It is not recommended for breastfeeding mothers either.
• History of ulcers: Hydroxyurea may cause or worsen stomach ulcers.
• Infection or immunocompromised state: Since Hydroxyurea can lower white blood cell counts, it may make you more vulnerable to infections.

Regular Monitoring and Tests

While you are taking Hydroxyurea, your doctor will monitor your health with regular blood tests, including:

• Blood counts: To check for low red blood cells, white blood cells, and platelets.
• Liver and kidney function tests: To make sure your liver and kidneys are working properly.
• Complete blood count (CBC): This helps your doctor monitor for any signs of anemia, infection, or bleeding.

Drug Interactions

Hydroxyurea may interact with other medications. Be sure to tell your doctor about all the medications you are taking, including:

• Prescription medications
• Over-the-counter medications
• Herbal supplements and vitamins
• Any chemotherapy or cancer treatments

Certain medications may affect how Hydroxyurea works or increase the risk of side effects. Always check with your doctor before starting or stopping any medications.

What to Do in Case of an Emergency

If you experience any of the following serious symptoms, get medical help immediately:

• Difficulty breathing, swelling of the face, lips, tongue, or throat
• Severe dizziness or fainting
• Unusual bleeding or bruising
• Jaundice (yellowing of the skin or eyes)
• Severe abdominal pain or changes in urination

Pregnancy and Breastfeeding

• Pregnancy: Hydroxyurea can harm an unborn baby. If you are pregnant, plan to become pregnant, or think you might be pregnant, inform your doctor right away. You should use effective birth control while taking Hydroxyurea.
• Breastfeeding: It is not known whether Hydroxyurea passes into breast milk. For this reason, you should not breastfeed while taking this medication.

Lifestyle Tips

• Hydration: Drink plenty of fluids to prevent dehydration, which can help with side effects like constipation and skin dryness.
• Avoid infection: Since Hydroxyurea can lower your white blood cell count, it may make you more susceptible to infections. Take steps to avoid close contact with people who are sick, and wash your hands frequently.
• Regular check-ups: Be sure to attend all follow-up appointments with your doctor to monitor your progress and blood work.

Conclusion

Hydroxyurea is an effective treatment for conditions like chronic myelogenous leukemia (CML), sickle cell disease, and other blood disorders. While it can help manage these conditions, it is important to be aware of the potential side effects and risks. Make sure to follow your doctor’s instructions carefully, and report any side effects or changes in your health.

If you have any questions or concerns about your treatment with Hydroxyurea, speak with your healthcare provider.

Disclaimer: This handout is for educational purposes only and is not intended as medical advice. Always consult your healthcare provider for specific medical guidance regarding your treatment.