Last Updated: 2023-10-26

Precautions for Patients Taking Tamoxifen or Aromatase Inhibitors

Mary Heery, APRN, AOCNS®, CBCN

From Nuvance Health, Norwalk, Connecticut

Correspondence to: Mary Heery, APRN, AOCNS®, CBCN, 34 Maple Street, Norwalk, CT 06856 E-mail:

J Adv Pract Oncol 2023;14(6):478–482 | | © 2023 BroadcastMed LLC



Tamoxifen and aromatase inhibitors are widely prescribed therapies for the treatment of breast cancer. Tamoxifen is a selective estrogen receptor modulator that treats hormone-sensitive breast cancers. Research has demonstrated that tamoxifen therapy improves survival and reduces the risk of developing recurrent invasive breast cancer by up to 40%.


Aromatase inhibitors are the drug of choice for the treatment of estrogen receptor– or progesterone receptor–positive breast cancer in postmenopausal women. Research on aromatase inhibitors has demonstrated improved survival in postmenopausal women, postmenopausal women with metastasis, and premenopausal women under the age of 35 with ovarian ablation.


The benefits of these agents have been clearly shown through various clinical trials, yet adherence may be challenging for some patients due to issues of drug interactions, proper education, and adverse effects. Education to prevent and treat adverse effects is of the utmost importance to promote adherence and improve the effectiveness of these medications. Advanced practitioners are in a position to prescribe these therapies, review medication interactions, educate patients, impact patients’ quality of life, improve patients’ sense of control, and increase patients’ partnerships with their oncology providers.


In 2018 and 2020, two articles on precautions for patients taking tamoxifen and precautions for patients taking aromatase inhibitors were published in the Journal of the Advanced Practitioner in Oncology (Heery et al., 2018, 2020). Since then, more information on drug interactions has come to light. This article contains updated patient teaching sheets to aid the advanced practitioner in providing education to patients on these medications (Tables 1 and 2). Permission to reprint and distribute these sheets is granted.


Click the images below to download a pdf of the handouts.



Heery, M., Corbett, P., & Zelkowitz, R. (2018). Precautions for patients taking tamoxifen. Journal of the Advanced Practitioner in Oncology, 9(1), 78–83.

Heery, M., Farley, S., Sparkman, R., Healy, J., Eighmy, W., Zahrah, G., & Zelkowitz, R. (2020). Precautions for patients taking aromatase inhibitors. Journal of the Advanced Practitioner in Oncology, 11(2), 184–189.