CYP2C19 and allergic disease: A multivariate analysis - accounting for age, medication tenure, allergies, PHQ-9, malaise/fatigue, and medication indication - revealed a significant association between metabolizer status and discontinuation for CYP2C19 increased metabolizers (ultrarapid plus rapid metabolizers) compared to normal metabolizers (n = 4 635) (HR = 1.17 [1.08, 1.27], p < 0.001) for CPIC guideline-recommended medications (i.e., citalopram, escitalopram, sertraline).