title: Side effects of hydroxyurea in patients with Thalassemia major and thalassemia intermedia and sickle cell anemia.
abstract: BACKGROUND
  Sickle hemoglobin is the most common abnormal hemoglobin in the United States. Hemoglobin S arises as a result of a single amino acid substitution (glutamic acid to valin at position 6 of the β-globine chain). The presence of fetal hemoglobin (HbF) plays a relatively protective role since a significant amount of HbF interferes with HbS polymerization, the pathogenesis mechanism of the vaso-occlusive symptoms that are the major contributor of the morbidity and mortality of this condition Thalassemia major and thalassemia intermedia have no specific molecular correlate but encompass a wide spectrum of clinical and laboratory abnormalities. Hydroxyurea (HU), an s-phase-specific and non-DNA-hypomethylating chemotherapeutic agents is capable of inducing HbF synthesis.
  
  
  METHODS
  This study was done on 56 patients, 28 patients with sickle cell anemia (SCA) and 28 patients with intermediate or major β-thalassemia. Start dose of HU was 10 mg/kg per day and increased by 5 mg/kg per day every 4-6 weeks until toxicity or according to clinical response.
  
  
  RESULTS
  The side effects were dermatologic in 39.28%, neurologic 23.2%, gastrointestinal 17.5% and hematologic 10.71% of patients. the statistical analysis didn't show significant relationship between variables such as history of blood transfusion, duration of HU treatment, age of start HU, age of diagnosis, dose of HU and ethnic with occurrence of HU adverse effects.
  
  
  CONCLUSIONS
  The HU therapy in our patients tolerated well and side effects were minor to moderate, benign and transient.
authors.affiliation: Assistant professor of pediatric hematology and oncology, faculty of medicine , Mashhad University of Medical Sciences, Mashhad,Iran.
authors.forename: A
authors.initials: A
authors.lastname: Ghasemi
authors.affiliation: Associate professor of pediatric hematology and oncology, Jondishapour University of Medical Sciences, Ahvaz, (research center for thalassemia and hemoglobinopathy).
authors.forename: B
authors.initials: B
authors.lastname: Keikhaei
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad/Iran.
authors.forename: R
authors.initials: R
authors.lastname: Ghodsi
keywords: Sickle cell anemia; Side effects; hydroxyurea; β-Thalasemia