Characteristics of adverse drug reactions induced by flutamide and bicalutamide: a real-world pharmacovigilance study using FAERS.

Background: Flutamide and bicalutamide are indicated for the management of prostate metastatic carcinoma. The current study evaluated the adverse drug reactions related to flutamide and bicalutamide in a real-world setting.

Methods: To quantify the signals of flutamide and bicalutamide associated adverse events (AEs), we used the US Food and Drug Administration Adverse Event Reporting System (FAERS) for this pharmacovigilance study using established pharmacovigilance methods.

Results: A total of 2711 AEs of flutamide were investigated as the primary suspected; 522 AEs were related to prostate cancer. A total of 4459 AEs were investigated as the primary suspected for bicalutamide; 2251 AEs were related to prostate cancer. The analysis demonstrated 29 signals for flutamide and 84 for bicalutamide. Liver function test was the most common AEs for flutamide, and malignant neoplasm progression was the most common for bicalutamide. The signal strength of Dementia Alzheimer's type was 26.53 (17.89-39.35) and 26.33 (607.34), which had the highest strength for flutamide. Anti-androgen withdrawal syndrome exhibited the strongest signal for bicalutamide. Generating awareness of rare AEs that were not listed on the label is critical.

Conclusions: The analysis of the AE signals may provide support for prescribing flutamide and bicalutamide.