Pediatric guanfacine exposures reported to the National Poison Data System, 2000-2016

Introduction: The purpose of this study was to characterize the frequency, reasons for exposure, clinical manifestations, treatments, duration of effects, and medical outcomes of pediatric guanfacine exposures reported to the National Poison Data System (NPDS) from 2000 to 2016.Methods: Data extracted from poison control center call records for pediatric (0-5 years, 6-12 years, and 13-19 years), single-substance guanfacine ingestions reported to NPDS between 2000 and 2016 was retrospectively analyzed.Results: A total of 10927 cases were identified for analysis. Pediatric single-substance guanfacine exposures reported to NPDS increased significantly during the study period, with a marked increase among 6-12-year-olds. The most commonly documented clinical effects across age groups were drowsiness (n = 4262, 39%), bradycardia (n = 1696, 15.5%), and hypotension (n = 1127, 10.3%). The duration of effect for most cases was >8 hours but ≤24 hours (n = 2395, 44.2%). The median documented quantity of guanfacine ingested was 0.11 mg/kg (range: 0.004-7.8 mg/kg). The difference between mg/kg ingested in no effect and minor effect groups compared to moderate and major effect groups was statistically significant in all three age groups.Conclusions: Pediatric guanfacine exposures reported to U.S. poison centers have increased significantly in the last fifteen years. The most common clinical findings secondary to guanfacine exposure were bradycardia, hypotension, and CNS depression. There was a statistically significant difference between the mg/kg of guanfacine ingested in the groups experiencing no effect or mild effect compared to moderate or major effects. However, the maximum ingested dose reported among 0-5-year-olds in the no effect group was 2.72 mg/kg, while the minimum dose eliciting a major effect in both 0-5 and 6-12-year-olds was 0.05 mg/kg. The overall incidence of major effects was very low, with the vast majority of patients experiencing minor symptoms or less. Based on this data, we agree with current recommendations that any symptomatic pediatric patient exposed to guanfacine should be observed in a health care facility for at least 24 hours.