Clinical Complications in Severe Pediatric Sickle Cell Disease and the Impact of Hydroxyurea

Background More evidence of the safety and effectiveness of hydroxyurea (HU) in community based cohorts of pediatric patients with sickle cell disease (SCD) are needed The association of HU with organ specific clinical complications and adverse events is examined herein Methods Medicaid medical and pharmacy claims for the calendar years January 1996 through December 2006 were used to identify a cohort of children and adolescent patients (ages 17 and under) with a diagnosis of SCD (homozygous) who were treated with HU and developed disparate complications or adverse side effects Of the 2 194 pediatric SCD patients identified 175 (8%) were treated with HU Incidence density matching (1 case 2 controls) was used to select the control group on age gender ethnicity time in the Medicaid data set, and baseline severity resulting in a total study cohort of 523 cases Results Organ specific complications were more likely in the HU treated group compared to non HU treated group cardio vascular complications (odds ratio [OR] = 3 15 confidence interval [CI] = 1 97-5 03) hepatic complications(OR 5 41, CI = 3 54-8 27) renal complications (OR 5 09 CI 3 37-7 67), and pulmonary complications (OR 4 07 CI 1 88-8 79) Many of these conditions began developing before HU was prescribed Developing three or more complications was also more likely in the HU group (27 4% vs 7 0% P < 0 0001) Conclusions Extending previous findings to routine practice settings, HU is being administered to the most severely ill children with SCD many of whom had already started to develop organ specific complications but it is not associated with development of serious adverse events Pediatr Blood Cancer 2011 5690-94 (C) 2010 Wiley Liss Inc