Hydrea, also known by its generic name hydroxyurea, is a medication primarily used in the treatment of certain cancers and sickle cell anemia. It works by inhibiting the synthesis of DNA in rapidly dividing cells, which helps to slow down or stop the growth of cancer cells. In the case of sickle cell anemia, Hydrea helps to increase the production of fetal hemoglobin, which can reduce the number of sickle cells and decrease the frequency of painful crises. It is administered orally in capsule form. As with any medication, Hydrea can have side effects, and its use should be closely monitored by a healthcare professional to ensure its benefits outweigh any potential risks.