Hydroxyurea in sickle cell anemia.
| Indications for treatment |
| Adults, adolescents, and after consultation with parents and expert pediatricians, children with sickle cell anemia or HbS-β0 thalassemia and frequent pain episodes, history of acute chest syndrome, other severe vasoocclusive complications. Severe symptomatic anemia |
| Baseline evaluation |
| Blood counts, red cell indices, HbF, serum chemistries, pregnancy test, willingness to adhere to all recommendations for treatment, absence of chronic transfusion program |
| Initiation of treatment |
| Hydroxyurea 10-15 mg/kg/day in a single daily dose for 6-8 weeks, CBC q 2 weeks, HbF q 6-8 weeks; serum chemistries q 2-4 weeks |
| Continuation of treatment |
| If counts are acceptable, escalate dose every 6 to 8 weeks until the desired end point is reached. |
| Treatment endpoints |
| Less pain, increase in HbF to 15-20%, increased hemoglobin level if severely anemic, improved well-being, acceptable myelotoxicity. |
| Failure of HbF (or MCV) to increase |
| Consider biological inability to respond to treatment or poor compliance with treatment. Increase dose very cautiously to 2000-2500 mg daily (maximum dose 30 mg/kg). Absent transfusion support or intercurrent illness suppressing erythropoiesis, a trial period of 6 to 12 months is probably adequate. |
| Cautions |
| Special caution should be exercised in patients with compromised renal or hepatic function. Contraception should be practiced by both men and women since hydroxyurea is a teratogen and its effects in pregnancy are unknown. After a stable and non-toxic dose of hydroxyurea is reached, blood counts may be done at 4- to 8-week intervals. Granulocytes should be ≥ 2000/mm3, platelets ≥ 80,000/mm3. |
| Indications for treatment |
| Adults, adolescents, and after consultation with parents and expert pediatricians, children with sickle cell anemia or HbS-β0 thalassemia and frequent pain episodes, history of acute chest syndrome, other severe vasoocclusive complications. Severe symptomatic anemia |
| Baseline evaluation |
| Blood counts, red cell indices, HbF, serum chemistries, pregnancy test, willingness to adhere to all recommendations for treatment, absence of chronic transfusion program |
| Initiation of treatment |
| Hydroxyurea 10-15 mg/kg/day in a single daily dose for 6-8 weeks, CBC q 2 weeks, HbF q 6-8 weeks; serum chemistries q 2-4 weeks |
| Continuation of treatment |
| If counts are acceptable, escalate dose every 6 to 8 weeks until the desired end point is reached. |
| Treatment endpoints |
| Less pain, increase in HbF to 15-20%, increased hemoglobin level if severely anemic, improved well-being, acceptable myelotoxicity. |
| Failure of HbF (or MCV) to increase |
| Consider biological inability to respond to treatment or poor compliance with treatment. Increase dose very cautiously to 2000-2500 mg daily (maximum dose 30 mg/kg). Absent transfusion support or intercurrent illness suppressing erythropoiesis, a trial period of 6 to 12 months is probably adequate. |
| Cautions |
| Special caution should be exercised in patients with compromised renal or hepatic function. Contraception should be practiced by both men and women since hydroxyurea is a teratogen and its effects in pregnancy are unknown. After a stable and non-toxic dose of hydroxyurea is reached, blood counts may be done at 4- to 8-week intervals. Granulocytes should be ≥ 2000/mm3, platelets ≥ 80,000/mm3. |