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

Aim-To evaluate the tolerance off 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, 36 of whom were treated for more than three years. 13 children were younger than 5 years of age at inclusion. Results-Hydroxyurea was I;topped 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 1.5 months 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.