Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 6 4 2015 10 13 11 13 EN Ali Ghasemi Assistant professor of hematology and oncology, Mashhad University of Medical Sciences, Mashhad, Iran. Bijan Keikhaei Associate professor of hematology and oncology, Jondishapour University of Medical Sciences, Ahvaz, Iran. Saghi Elmi Resident of pediatric diseases, Mashhad University of Medical Sciences, Mashhad, Iran. 2015 10 13 2015 10 13 Introduction: Patients referred to as having thalassemia major are usually those who come to medical attention in the first year of life and subsequently require regular transfusions to survive. Those who present later or who seldom need transfusions are said to have thalassemia intermediaHydroxyurea, an s-phase-specific and non-DNA-hypomethylating chemotherapeutic agents is capable of inducing HbF synthesis. Patients & Methods: The study evaluated hydroxyurea complications in a cohort of 28 patients with major (n=20) and intermediate thalassemia (n=8). HU was started in a dose of 10 mg/kg daily and then increased by 5 mg/kg daily every 4-6 weeks until toxicity occurred or clinical response was achieved. Results: We reviewed the records of 28 patients with intermediate and major b-thalassemia. The statistical analysis did not show a significant correlation between age at diagnosis, age of starting HU, duration of HU treatment, dose of HU and ethnicity.Side effects of HU have been recorded in 21 (75%) patients.Adverse effects were hair loss (n=8; 28.57%), hyper pigmentation (n=4; 14.28%), nausea and vomiting (n=2; 7.14%), abdominal pain (n=4; 14.28%), and increase in hepatic enzymes (n=2; 7.14%).Neurologic complications were headache (n=7; 25%), vertigo (n=1; 3.57%) and drowsiness (n=1; 3.57%). Conclusion: According to the results of this and other studies, it seems that HU therapy in thalassemic patients can be safely used but can be started at low doses and increased slowly , monitoring the patient's response. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/355 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/355/323