CYP2D6 and major depressive disorder: The patient was also on non-cancer medications including ondansetron (CYP2D6—CPIC Level A) for nausea, hydrocodone (CYP2D6—CPIC Level B), tramadol (CYP2D6—CPIC Level A, FDA Tier 1), and ibuprofen (CYP2C9—CPIC Level A) for pain, and paroxetine (CYP2D6—CPIC Level A, FDA Tier 3) for depression [31].