AGENT FOR SICKLE CELL ANEMIA

Hydroxyurea is a cytotoxic antineoplastic drug that is also used to treat leukemia, ovarian cancer,and melanoma.

Therapeutic Actions and Indications Hydroxyurea, taken for several months, increases the amount of fetal hemoglobin produced in the bone marrow and dilutes the formation of the abnormal hemoglobin S in adults who have sickle cell anemia. This results in less clogging of small vessels and the painful, anoxic effects associated with the RBC sickling or stacking.

Pharmacokinetics Given orally, hydroxyurea is absorbed well from the GI tract, reaching peak levels in 1 to 4 hours. It is metabolized in the liver and excreted in the urine with a half-life of 3 to 4 hours. It is known to cross the placenta and to enter breast milk.

Contraindications and Cautions Hydroxyurea is contraindicated with known allergy to any component of the drug to prevent hypersensitivity reactions and with severe anemia or leucopenia because it can cause further bone marrow suppression. It should be used with caution in the presence of impaired liver or renal function, which could interfere with metabolism and excretion of the drug, and it should only be used in pregnancy and lactation if the benefi t to the mother clearly outweighs the potential risk to the fetus or baby because this drug crosses the placenta and enters breast milk and could cause serious effects in the fetus or baby.

Adverse Effects Hydroxyurea is cytotoxic and is associated with adverse effects associated with the death of cells, especially in cells that are rapidly turning over. GI effects include anorexia,nausea, vomiting, stomatitis, diarrhea, or constipation;dermatological effects include rash or erythema;and bone marrow suppression usually occurs. Headache,dizziness, disorientation, fever, chills, and malaise have been reported, possibly related to the effects of cell death in the body. As with other cytotoxic drugs, there is an increased risk of cancer development.