The Role of Hydroxyurea and the Clinical Outcome of Paediatric Sickle Cell Disease Patients in a Tertiary Hospital in North-Western Nigeria

Abstract

Background: Sickle cell disease (SCD) is a common condition in Nigeria that is associated with high morbidity and mortality among children. The use of hydroxyurea (HU), a disease-modifying agent that induces the synthesis of foetal haemoglobin, is limited by efficacy and safety concerns. This study aimed to assess the relationship between the use of HU and the frequency of adverse clinical events among paediatric SCD patients at a tertiary hospital in Northwestern Nigeria. Methods: Using a retrospective cohort study design, a pro forma was used to extract data from 192 medical records of patients on HU therapy, including sociodemographic characteristics, pattern of HU use and adverse clinical events before and after the initiation of HU. For each of these adverse clinical events, incidence rates (IRs) and incidence rate ratios (IRRs) were calculated and assessed for statistical significance. Results: During the study period, patients on HU were 13 times less likely to experience vaso-occlusive crisis (IRR=0.07, 95%CI: 0.05–0.12) and six times less likely to require hospital admission (IRR=0.16, 95%CI: 0.11–0.22). The use of HU was associated with an increase in patients' mean packed cell volume (3.2%, t191=8.222, P<0.01). Starting HU was not associated with significant changes in the prevalence of therapy-related side effects (8.9% versus 12.5%, χ2=1.338, P=0.247). Conclusion: Use of HU was associated with significant reductions in the incidence of all adverse clinical outcomes. There is a need for wider studies to further validate these findings, address the limitations of retrospective designs, and understand the factors limiting the wider use of HU.