THE EFFECT OF CYP2D6 INHIBITORS ON THE THERAPEUTIC EFFICACY OF TAMOXIFENE: LITERATURE REVIEW

INTRODUCTION: Tamoxifen is a selective estrogen receptor modulator and is used to reduce the risk of recurrence of malignant breast cancer, which leads to greater survival in women with this disease. The use of tamoxifen as an adjuvant dramatically decreases the risk of cancer-specific recurrence and mortality. This medication is more accurate than traditional chemotherapies, as there are fewer side effects than other chemotherapeutics. The transformation of tamoxifen initially takes place via hepatic cytochrome P450 into active metabolites. It occurs through the CYP2D6 enzyme, being the main enzyme that participates in the bioactivation of tamoxifen. Endoxifene plasma indices are influenced by the CYP2D6 genotype and the use of drugs that affect CYP2D6 activity. CYP2D6 inhibitors are a broad spectrum of drugs that decrease enzyme activity. OBJECTIVE: The aim of this work is to elucidate, through a literature review, the main drugs that inhibit CYP2D6 and how they influence the therapeutic effect of tamoxifen. METHODS: This present work is a documental, quantitative and literature review research, and for its accomplishment, searches were carried out in electronic databases in Scientific Electronic Library Online (Scielo), MEDLINE, Pubmed, Web Of platforms Science, Science Direct, World Wide Science in a period of six months, using articles that were published during the years 2010 to 2020. RESULTS: The use of drugs that inhibit the CYP2D6 enzyme can be potentially harmful to patients who use tamoxifen in their treatment, causing a decrease in therapeutic efficacy and making it difficult to cure the disease. CONCLUSION: There are several drugs that affect therapeutic efficacy through inhibition of the CYP2D6 enzyme, requiring care and careful observation by health professionals, so that future errors can be avoided. Literature proves that interactions affect the quality of treatment of patients with breast cancer, being able to harm the health of these individuals.