NCCN Guidelines for Patients® | Myeloproliferative Neoplasms
26 NCCN Guidelines for Patients ® : Myeloproliferative Neoplasms, 2018 3 Essential thrombocythemia Initial treatment Cytoreductive treatment Cytoreductive treatment reduces the number of certain cells. For ET, the goal of treatment is to reduce platelets to normal levels. Normal levels prevent blood clots and other health problems. Cytoreductive treatment for initial treatment is based on risk group. It is not needed for very low-, low, and intermediate-risk ET. Cytoreductive treatment is advised for high-risk ET. There are three options for cytoreductive treatment. Hydroxyurea is the gold standard. Most people with ET on cytoreductive treatment take hydroxyurea. It should not be taken during pregnancy or while breastfeeding. Interferon is another option for some people. You may switch from hydroxyurea to interferon before and during pregnancy. Interferon may be received if you are 60 years of age or younger to avoid developing AML. Some people defer taking hydroxyurea by taking interferon. More information on interferon is on page 37. Anagrelide has been used as a third option. It works as well as hydroxyurea to control platelet counts. However, its side effects may be worse. There is a greater chance for blood clotting. More information on anagrelide is on page 29. What is hydroxyurea? Chemotherapy, or “chemo,” includes drugs that disrupt the life cycle of cancer cells. Hydroxyurea is a type of chemotherapy called an antimetabolite. This type prevents the “building blocks” of DNA from being used. As a result, new cells can’t be made. Hydroxyurea is made as a pill to be swallowed. Your doctor will tell you what dose you need and how often to take it. Do not take hydroxyurea right before getting pregnant, during pregnancy, or if you’re breastfeeding. Hydroxyurea lowers blood counts. Thus, you will be at risk for anemia, infection, and bleeding. Other common side effects include minor hair loss, nausea and vomiting, diarrhea, mouth sores, and skin and nail changes. Not all side effects of hydroxyurea are listed here. Please ask your treatment team for a complete list of common and rare side effects. If a side effect bothers you, tell your treatment team. There may be ways to help you feel better. There are also ways to prevent some side effects.