Hydroxyurea (Hydrea) — Droxia: Sickle Cell & Leukemia
Hydroxyurea (also known as Hydroxycarbamide) is a time-tested workhorse in hematology. While not a new targeted therapy, it acts as a reliable "brake pedal" for an overactive bone marrow.
In conditions like polycythemia or thrombocythemia, the blood becomes thick and sludge-like due to excess cells. Hydroxyurea (Hydrea, Droxia) interferes with DNA synthesis, gently lowering the count of platelets and red blood cells to prevent dangerous clots.
For Sickle Cell Anemia, it works almost like magic: it stimulates the production of fetal hemoglobin (the kind babies have). This prevents red blood cells from turning into rigid, sticky "sickles," saving patients from agonizing pain crises and organ damage.
Indications
- Myeloproliferative Disorders: Polycythemia Vera (too many RBCs), Essential Thrombocythemia (too many platelets).
- Chronic Myeloid Leukemia (CML): Often used initially to rapidly bring down high white blood cell counts.
- Sickle Cell Disease: To reduce the frequency of painful crises and the need for blood transfusions in adults and children.
- Cervical Cancer: Used as a radiosensitizer alongside radiation therapy.
Dosage and administration
Dosage is strictly calculated based on the patient's actual or ideal body weight ($mg/kg$).
- Instructions: Capsules are taken orally, usually once a day, with a full glass of water.
- Safety Warning: As a chemotherapy agent, capsules must be handled with care. Pregnant women should not touch the capsules or handle the bottle, as the drug can be absorbed through the skin and harm the fetus.
- Hydration: Drink plenty of fluids to help your kidneys flush out the breakdown products of cells.
- Pregnancy and breastfeeding (severe teratogenic risk).
- Severe bone marrow depression (very low leukocytes or platelets) prior to treatment.
- Severe anemia.
Because it affects all rapidly dividing cells, skin and blood side effects are common.
- Hematologic: Bone marrow suppression (neutropenia, anemia). Regular blood tests are mandatory to ensure the dosage isn't too high.
- Skin (Specific): Darkening of the skin (hyperpigmentation), nail changes. Long-term use can lead to painful leg ulcers (especially around the ankles) — report these immediately.
- Reproductive: Can cause temporary infertility in men (low sperm count).
- Digestive: Nausea, mouth sores.
