A two-year pilot trial of hydroxyurea in very young children with sickle-cell anemia

J Pediatr. 2001 Dec;139(6):790-6. doi: 10.1067/mpd.2001.119590.


Objective: Hydroxyurea improves hematologic values and decreases vaso-occlusive complications in adults and children with sickle cell anemia (SCA), but has not been tested in infants before the onset of chronic organ dysfunction. We conducted a collaborative pilot trial of hydroxyurea in infants with SCA to assess its (1) feasibility of administration, (2) toxicity, (3) hematologic effects, and (4) effect on spleen function.

Study design: Patients with hemoglobin (Hb) SS or Sbeta(0) thalassemia (n = 28, median age 15 months) received hydroxyurea for 2 years at 20 mg/kg/day. Hydroxyurea was temporarily discontinued for predefined toxicity.

Results: Seven patients exited the study early: five for noncompliance or refusal to continue, one for mild stroke, and one for fatal splenic sequestration. The predominant toxicity was transient neutropenia, which was usually associated with a viral-like illness. After 2 years of treatment, mean Hb level = 8.8 g/dL and Hb F = 20.3%, both higher than predicted age-specific levels. Radionuclide splenic uptake was absent in 47% of patients at study completion, compared with predicted functional asplenia in 80% of the patients.

Conclusions: Hydroxyurea therapy for infants with SCA is feasible and well tolerated, has hematologic efficacy, and may delay functional asplenia. The potential for hydroxyurea to preserve organ function in SCA should be further evaluated.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Anemia, Sickle Cell / blood
  • Anemia, Sickle Cell / complications
  • Anemia, Sickle Cell / drug therapy*
  • Antisickling Agents / adverse effects
  • Antisickling Agents / therapeutic use*
  • Antisickling Agents / toxicity
  • Blood Cell Count
  • Child, Preschool
  • Feasibility Studies
  • Female
  • Hematologic Diseases / blood
  • Hematologic Diseases / chemically induced
  • Hemoglobins / analysis
  • Hemoglobins / drug effects*
  • Humans
  • Hydroxyurea / adverse effects
  • Hydroxyurea / therapeutic use*
  • Hydroxyurea / toxicity
  • Infant
  • Male
  • Pilot Projects
  • Splenic Diseases / blood
  • Splenic Diseases / etiology
  • Splenic Diseases / prevention & control*
  • Time Factors


  • Antisickling Agents
  • Hemoglobins
  • Hydroxyurea