Pronunciation(s): drock-SEE-yuh; high-drox-e-you-REE-ah
What is hydroxyurea?
- Hydroxyurea is approved as an antineoplastic. Antineoplastics are used to treat cancer. Hydroxyurea is used to treat melanoma (a type of skin cancer), chronic myelocytic leukemia (CML), cancer of the ovary, and primary squamous cell (skin) cancer of the head and neck.
- Hydroxyurea has also bee studied as a potential treatment for HIV infection. Although it is not approved by the U.S. Food and Drug Administration for this purpose, some HIV-positive people do use it, usually in combination with approved anti-HIV drugs. Because the use of hydroxyurea for the treatment of HIV infection is considered to be experimental, it is very important that you work closely with a healthcare provider familiar with the potential benefits and side effects of this drug. There are no official guidelines or recommendations regarding the use of hydroxyurea for the treatment of HIV infection.
- If hydroxyurea is prescribed, it should be used carefully by HIV-positive people who have low T-cell counts (e.g., below 200 cells/mm3). Hydroxyurea can cause a decrease in the number of T-cells and can cause serious side effects in people with impaired immune systems.
- Serious, even fatal, cases of pancreatitis (inflammation of the pancreas) have been reported in people who combined hydroxyurea with Videx® or Videx EC® (ddI). Notify your doctor immediately if you develop symptoms of pancreatitis including nausea, vomiting, diarrhea, abdominal pain. Avoid alcohol while you are taking hydroxyurea and Videx or Videx EC. Alcohol may increase the risk of damage to your pancreas.
What is already known about hydroxyurea?
- Unlike other drugs used to treat HIV, hydroxyurea does not attack the virus. Hydroxyurea targets the immune system, specifically T-cells.
- HIV infects T-cells. When HIV-infected T-cells attempt to divide – a normal function of T-cells – they end up producing thousands of new HIV viruses and releasing them into the body. Hydroxyurea stops T-cells from dividing. This is believed to reduce the amount of HIV produced by T-cells.
- Because hydroxyurea targets T-cells and not the virus, many researchers believe that resistance to this drug occurs very slowly, if at all. Most people who have been using hydroxyurea in clinical trials or under the care of their own doctors have not shown any signs of resistance to the drug.
- A safe and effective dose for hydroxyurea for the treatment of HIV has not been established or approved by the FDA. In clinical trials, the usual dose was 500mg twice a day (no more than 1,000mg a day).
- Clinical trials of hydroxyurea, in combination with other anti-HIV drugs, have produced conflicting results. In small studies combining hydroxyurea with Zerit® (d4T) and Videx® (ddI), there was noticeable anti-HIV activity. However, in a larger clinical trial, hydroxyurea was not associated with any additional benefits when combined with a regimen containing a protease inhibitor, Zerit, and Videx. What's more, the study was stopped early because of a higher rate of side effects (e.g., pancreatitis, low white blood cell counts, low red blood cells, and peripheral neuropathy) in study volunteers who combined hydroxyurea with their other drugs.
What are the possible side effects of hydroxyurea?
- The most serious side effects of hydroxyurea involve the blood, and may include severely low white blood cell counts (leukopenia, neutropenia), which can decrease your resistance to infections. Hydroxyurea can also cause severely low red blood cell counts (anemia) and/or severely low platelet counts (thrombocytopenia), which can can cause excessive bleeding.
- Inflammation of the pancreas (pancreatitis), which can be life-threatening, has been reported in HIV-positive people combining hydroxyurea with Videx.
- It is very important that your doctor measure your blood counts regularly while you are taking hydroxyurea.
- In clinical trials using high doses of hydroxyurea for the treatment of sickle cell anemia and cancers, common side effects included hair loss, skin rash, fever, stomach and/or bowel disturbances, weight gain, bleeding, discolored nails.
Who should not take hydroxyurea?
- Hydroxyurea is in the FDA pregnancy category D. This means that hydroxyurea will harm an unborn baby. Do not take this medication if you are pregnant or planning a pregnancy without first talking to your doctor.
- It is not known whether hydroxyurea passes into breast milk. Do not take this medication without first talking to your doctor if you are breast-feeding.
What about drug interactions?
- Caution should be used when combining hydroxyurea with other medications known to cause bone-marrow toxicity, such as decreased white blood cells, decreased red blood cells, and decreased platelets. Many medications used to treat AIDS-related diseases and some anti-HIV medications can increase the risk of bone-marrow toxicity caused by hydroxyurea.
Where can I get more information?
- Your pharmacist has additional information about hydroxyurea written for health professionals that you may read.
- If you would like to find out if you are eligible for any clinical trials that include hydroxyurea, visit ClinicalTrials.gov, a site run by the U.S. National Institutes of Health. The site has information about all HIV-related clinical studies in the United States. For more info, you can call their toll-free number at 1-800-HIV-0440 (1-800-448-0440) or email firstname.lastname@example.org.