The Indian experience with hydroxyurea in sickle cell disease: A 25-year systematic review

Background & objectives Sickle cell disease (SCD) is an inherited blood disorder caused by a mutation in the β-globin gene, leading to the production of abnormal haemoglobin and the deformation of red blood cells into a sickle shape. This results in serious complications, including vaso-occlusive crises (VOC), chronic anaemia, infections, stroke, acute chest syndrome, delayed growth, and multi-organ damage. SCD poses a significant public health burden in India, particularly among tribal populations. Hydroxyurea (HU) is a disease-modifying therapy known to increase foetal haemoglobin (HbF) levels and reduce SCD-related complications. This review aims to evaluate the efficacy and safety of HU in Indian SCD patients. Methods A systematic review of 27 Indian studies (involving 3,817 patients with SCD), published between January 2000 and August 2024, was conducted. Studies were sourced from major databases, and included clinical trials, prospective and retrospective studies, and observational cohorts. Key outcomes assessed were HbF levels, VOC frequency, transfusion requirements, hospitalizations, and adverse effects. Results HU significantly increased HbF levels (10.9-77.3%), reduced VOC frequency by 79-93 per cent, and lowered transfusion needs by 50-85 per cent. Hospitalisations and anaemia also improved. HU was generally safe, with mild, reversible side effects like neutropenia and thrombocytopenia in few cases. Interpretation & conclusions HU is effective and well tolerated in Indian patients with SCD.