Signals of adverse drug events of Tamoxifen: An analysis of FDA Adverse Event Reporting System data from 2015 to 2020

Purpose: The purpose of this study is to identify adverse drug events signals of tamoxifen through analyze the US FDA Adverse Event Reporting System (FAERS) data from 2015 to 2020. Method: Disproportionality analysis was used to identify adverse drug events(AEs) signals associated with tamoxifen as the primary suspect drug from January 1, 2015 to June 30, 2020. AEs are preferred terms (PTs) defined in MedDRA23.1 and the drug name was standardized by MedEx_UIMA_1.3.8. We used frequentist approaches and Bayesian approaches, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR) and Bayesian confidence propagation neural network (BCPNN) to determine signals. Signals were defined as the number of reports ≥ 3 and the lower limit of 95% confidence intervals (CI) of ROR ≥ 1, PRR ≥ 2, IC > 0, and chi-squared of PRR ≥4. Results: : A total of 1496 adverse event reports associated with tamoxifen were involved in the statistic analysis. The male to female ratio of 1496 reports was 1:16.29(234 reports without gender information). The most frequently reported outcome except “Other Serious” is “Hospitalization-Initial or Prolonged”(17.98%). a total of 77 signals were identified, including“Malignant neoplasm progression”, “Hepatic cirrhosis”, “Non-alcoholic steatohepatitis”and so on, involving 18 System Organ Classes(SOCs). Conclusions: : Medical staff should pay special attention to the nervous system adverse events caused by tamoxifen, especially in high-risk patients with Alzheimer’s disease. And the reason of it may be that tamoxifen inhibit estrogen in brain.