Preliminary report of a toxicity study of hydroxyurea in sickle cell disease

AIM—To evaluate the tolerance of hydroxyurea in children affected with sickle cell disease. DESIGN—Questionnaire study of French physicians likely to treat patients with sickle cell disease. Data were collected on 101 children with sickle cell disease, treated for a median of 22 months, 36of whom were treated for more than three years. 13 children were younger than 5 years of age at inclusion. RESULTS—Hydroxyurea was stopped for medical reasons in 11 patients: 6 failures, 1 pregnancy, 1 cutaneous rash, 1 leg ulcer, 1 lupus. Acute lymphoblastic leukaemia occurred in a girl treated for 1.5months with hydroxyurea, this short interval arguing against a causative association. One 17 year old boy had paraparesis after 8 years of treatment. CONCLUSIONS—No major short or medium term toxicity was related to hydroxyurea in this cohort of 101 children. However, the number of children treated for more than 3 years is too few to make firm conclusions on the long term tolerance of this drug.