Hydroxyurea is a medication used to treat sickle cell anemia. It increases the amount of a healthy type of hemoglobin protein in red blood cells. This causes more normal shaped cells that do not impede blood flow. However, long term use of hydroxyurea has been linked with leukemia or tumors. Your doctor can best asses your risks for this type of medication. Over the counter medication is also used to control the pain in the chest, abdomen, and joints.