Hydroxyurea (Hydrea®)

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About This Drug

Hydroxyurea is used to treat cancer. It is given orally (by mouth).

Possible Side Effects

  • Bone marrow suppression. This is a decrease in the number of white blood cells, red blood cells, and platelets. This may raise your risk of infection, make you tired and weak (fatigue), and raise your risk of bleeding.
  • Nausea and throwing up (vomiting)
  • Diarrhea (loose bowel movements)
  • Constipation (not able to move bowels)
  • Decrease appetite (decreased hunger)

Note: Each of the side effects above was reported in 30% or greater of patients treated with hydroxyurea. Not all possible side effects are included above.

Warnings and Precautions

  • Severe bone marrow suppression
  • This drug may raise your risk of getting a second cancer, such as leukemia and skin cancer
  • Inflammation of your tissue and/or blood vessels. You may get redness, blisters and very rarely the tissues and/or vessels may die (necrosis).
  • Your red blood cells may become larger than normal which usually resolves on its own
  • If you have received radiation treatments, your skin may become red after hydroxyurea. This reaction is called “recall.” Your body is recalling, or remembering, that it had radiation therapy.

Note: Some of the side effects above are very rare. If you have concerns and/or questions, please discuss them with your medical team.

Important Information

  • Talk to your doctor before receiving any vaccinations during your treatment. Some vaccinations are not recommended while receiving hydroxyurea.

How to Take Your Medication

  • Swallow the medicine whole with or without food.Do not chew, break or crush it.
  • Missed dose: If you vomit or miss a dose, contact your physician for further instructions.  Do not take 2 doses at the same time and do not double up on the next dose.
  • Handling: Wash your hands after handling your medicine, your caretakers should not handle your medicine with bare hands and should wear latex gloves.
  • If you get any of the content of a broken capsules on your skin or in your eyes, you should wash the area of the skin well with soap and water right away. Wash your eyes with flowing water for at least 15 minutes and call your doctor. Call your doctor if you get a skin reaction.
  • This drug may be present in the saliva, tears, sweat, urine, stool, vomit, semen, and vaginal secretions. Talk to your doctor and/or your nurse about the necessary precautions to take during this time.
  • Storage: Store this medicine in the original container at room temperature.
  • Disposal of unused medicine: Do not flush any expired and/or unused medicine down the toilet or drain unless you are specifically instructed to do so on the medication label. Some facilities have take-back programs and/or other options. If you do not have a take-back program in your area, then please discuss with your nurse or your doctor how to dispose of unused medicine.

Treating Side Effects

  • Manage tiredness by pacing your activities for the day.
  • Be sure to include periods of rest between energy-draining activities.
  • To decrease infection, wash your hands regularly.
  • Avoid close contact with people who have a cold, the flu, or other infections.
  • Take your temperature as your doctor or nurse tells you, and whenever you feel like you may have a fever.
  • To help decrease bleeding, use a soft toothbrush. Check with your nurse before using dental floss.
  • Be very careful when using knives or tools.
  • Use an electric shaver instead of a razor.
  • Ask your doctor or nurse about medicines that are available to help stop or lessen constipation or diarrhea.
  • If you are not able to move your bowels, check with your doctor or nurse before you use enemas, laxatives, or suppositories.
  • Drink plenty of fluids (a minimum of eight glasses per day is recommended).
  • If you throw up or have loose bowel movements, you should drink more fluids so that you do not become dehydrated (lack water in the body from losing too much fluid).
  • To help with nausea and vomiting, eat small, frequent meals instead of three large meals a day. Choose foods and drinks that are at room temperature. Ask your nurse or doctor about other helpful tips and medicine that is available to help or stop lessen these symptoms.
  • If you get diarrhea, eat low-fiber foods that are high in protein and calories and avoid foods that can irritate your digestive tracts or lead to cramping.
  • Ask your nurse or doctor about medicine that can lessen or stop your diarrhea.
  • To help with decreased appetite, eat small, frequent meals. Eat foods high in calories and protein, such as meat, poultry, fish, dry beans, tofu, eggs, nuts, milk, yogurt, cheese, ice cream, pudding, and nutritional supplements.
  • Consider using sauces and spices to increase taste. Daily exercise, with your doctor’s approval, may increase your appetite. 
  • If you received radiation, and your skin becomes red or irritated again, follow the same care instructions you did during radiation treatment. Be sure to tell the nurse or doctor administering your chemotherapy about your skin changes.
  • Use sunscreen with SPF 30 or higher when you are outdoors even for a short time. Cover up when you are out in the sun. Wear wide-brimmed hats, long-sleeved shirts, and pants. Keep your neck, chest, and back covered.
  • If you get a rash do not put anything on it unless your doctor or nurse says you may. Keep the area around the rash clean and dry. Ask your doctor for medicine if your rash bothers you.

Food and Drug Interactions

  • There are no known interactions of hydroxyurea with food.
  • Tell your doctor and pharmacist about all the prescription and over-the-counter medicines and dietary supplements (vitamins, minerals, herbs and others) you are taking before starting this medicine as there are known drug interactions with hydroxyurea. Also, check with your doctor or pharmacist before starting any new prescription or over-the-counter medicines, or dietary supplements to make sure that there are no interactions.

When to Call the Doctor

Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

  • Fever of 100.4 F (38 C) or higher
  • Chills
  • Tiredness that interferes with your daily activities
  • Feeling dizzy or lightheaded
  • Easy bleeding or bruising
  • Nausea that stops you from eating or drinking and/or is not relieved by prescribed medicines
  • Throwing up more than 3 times a day
  • Diarrhea, 4 times in one day or diarrhea with lack of strength or a feeling of being dizzy
  • No bowel movement in 3 days or when you feel uncomfortable.
  • Lasting loss of appetite or rapid weight loss of five pounds in a week
  • A new rash or a rash that is not relieved by prescribed medicines
  • Develop sensitivity to sunlight/light
  • If you think you may be pregnant or may have impregnated your partner

Reproduction Warnings

  • Pregnancy warning: This drug can have harmful effects on the unborn baby. Women of childbearing potential should use effective methods of birth control during your cancer treatment and for at least 6 months after treatment. Men with female partners of childbearing potential should use effective methods of birth control during your cancer treatment and for at least 1 year after your cancer treatment. Let your doctor know right away if you think you may be pregnant or may have impregnated your partner.
  • Breastfeeding warning: Women should not breastfeed during treatment because this drug could enter the breast milk and cause harm to a breastfeeding baby.
  • Fertility warning: In men, this drug may affect your ability to have children in the future. Talk with your doctor or nurse if you plan to have children. Ask for information on sperm banking.

Revised June 2019

This patient information was developed by Via Oncology, LLC © 2019. This information is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have.

CLIENT acknowledges that the Via Pathways and Via Portal are information management tools only, and that Via Oncology, LLC has not represented the Via Pathways or Via Portal as having the ability to diagnose disease, prescribe treatment, or perform any other tasks that constitute the practice of medicine. The clinical information contained in the Via Pathways and Via Portal are intended as a supplement to, and not a substitute for, the knowledge, expertise, skill, and judgment of physicians, pharmacists and other healthcare professionals involved with patient care at CLIENT facilities.