{"This patient is predicted to have lower than normal CYP2D6 activity and may be at an increased risk of a poor tamoxifen response due to low endoxifen (active component of tamoxifen) concentrations. Consider hormonal therapy such as an aromatase inhibitor for postmenopausal women or aromatase inhibitor along with ovarian function suppression in premenopausal women. If aromatase inhibitor use is contraindicated, consideration should be given to use a higher but FDA approved tamoxifen dose (40 mg/day). Avoid CYP2D6 inhibitors. Please consult a clinical pharmacist for more information."}