363 - A Novel Study Assessing Pharmacogenetic Testing in Pediatric Patients with Chronic Pain

Poster Number: 363
Publication Number: 363.3242

Background: Chronic pain, defined as pain persisting for longer than three months, affects 20-35% of youth and profoundly impairs social, physical, and mental wellbeing. Further, one in five children experience persistent pain requiring pharmacological intervention. Pharmacogenetic (PGx) testing identifies genetic variants that may predict drug efficacy and/or toxicity. Leveraging PGx-guided pharmacotherapy may increase patient confidence and rate of adherence when taking medication, while potentially reducing adverse drug reactions and improving therapeutic responses. This study is the first to assess the implementation of PGx testing in pediatric patients with chronic pain.

Objective: To assess the feasibility and clinical utility of PGx testing in a cohort of children with chronic pain conditions.

Design/Methods: Genotyping of nine genes (NUDT15, CYP2C19, CYP2C9, CYP2D6, CYP3A5, F5, SLCO1B1, TPMT, VKORC1) with established PGx clinical guidelines was completed on a cohort of 43 pediatric patients with chronic pain. Medication history was collected via self-report and chart review. Feasibility, acceptability, and clinical utility of PGx testing were evaluated.

Results: Twenty-one patients (49%) were taking at least one medication with PGx clinical guidelines as part of their pharmacotherapy at the time of receiving PGx testing results. Of those, 12 (57%) were taking pain medications (e.g., ibuprofen, celecoxib) and 8 (38%) were taking medications used in treating commonly co-occurring psychiatric conditions in youth with chronic pain (e.g., sertraline, escitalopram). With respect to feasibility, 36 (84%) patients received testing results prior to their point of care visit for prescription of an analgesic. Finally, PGx testing enrollment differed between preemptive (recruited from waitlist) and reactive (established patients recruited as a referral) testing groups, with enrollment proportions representing 30/85 (35%) and 15/25 (60%) of patients approached, respectively.

Conclusion(s): This study addresses the lack of literature assessing PGx-guided medication prescribing in pediatric chronic pain. The results indicate that PGx testing appears to be relevant and feasible in a sample of children with chronic pain. Increased enrollment at point of care visits (versus while on waitlist) has important implications for the acceptability of PGx testing in families who have a child with chronic pain. The difference in willingness to undergo PGx testing between waitlist and referral groups suggests that patients and clinicians should be informed of the potential benefits of PGx testing prior to beginning pharmacotherapy.