Clinical Impact of Selective Serotonin Reuptake Inhibitors (SSRI) on the Therapeutic Response to Tamoxifen

Abstract

Tamoxifen is an antitumor drug widely used in the treatment of estrogen receptor-positive breast cancer. Due to the comorbidity between breast cancer and depressive disorder, and the adverse effects caused by tamoxifen, oncologists often prescribe tamoxifen and antidepressants concomitantly. The main goal of this study was to identify and discuss the available scientific evidence on the possible clinical impact of selective serotonin reuptake inhibitors (SSRI) antidepressants on the therapeutic response to tamoxifen. For that, an integrative literature review performed by Medline database via Pubmed search was conducted between April and July 2023. After selection according to eligibility criteria, seven studies were presented and discussed in this review, of which five were retrospective cohort studies and two case-control studies. The analysis of the results showed that there is still no consensus in the scientific literature about the real clinical impact of this potential drug interaction. As the available evidence is insufficient to establish a scientific consensus, it is initially recommended to avoid the co-administration of tamoxifen and potent CYP2D6 inhibitor antidepressants, such as paroxetine and fluoxetine, being prudent to replace them with less potent inhibitors, such as citalopram and escitalopram.