Youth are frequently prescribed psychotropic medications for moderate to severe mental health conditions. Pharmacogenetic (PGx) testing could potentially streamline current prescribing practices, which are often trial-and-error and complicated by side effects and lack of efficacy. Here, we estimated the proportion of youth who may benefit from PGx-guided psychotropic prescribing.
Participants aged 6-24 years were recruited through the Pharmacogenetic-Supported Prescribing in Kids study, an ongoing 12-month mirror image trial that is evaluating the implementation of PGx testing for children, adolescents, and emerging adults receiving mental health care in Western Canada. CYP2C19 and CYP2D6 testing results were used to calculate the proportion of participants with actionable genotypes for psychotropic medications with an available PGx-based dosing guideline. We also calculated the proportion of youth who were currently taking a psychotropic medication that was incongruent with their genotype.
Among the 538 participants included in this analysis, 82% had an actionable CYP2C19 (58.4%) or CYP2D6 genotype (52.0%). Sertraline (18%), fluvoxamine (9%), risperidone (8%), aripiprazole (7%), and atomoxetine (6%) were the most frequently prescribed psychotropic medications with a PGx-based dosing guideline. Furthermore, 10.2% of participants were currently taking a medication that was incongruent with their CYP2C19 or CYP2D6 genotype.
Prescribing of psychotropic medications with available PGx-based guidelines is common among youth and approximately one in every 10 youth are taking psychotropic medications that are incongruent with their PGx profile. These findings suggest that there is a potential benefit for PGx testing amongst pediatric populations taking psychotropic medications within Western Canada.