Evaluation of Potential Adverse Effects of Gender-Affirming Hormonal Therapy; Findings from the Spanish Pharmacovigilance System Database.

The Spanish Pharmacovigilance System for Medicines for Human Use (SEFV-H) is responsible for recording and evaluating adverse reactions suspected to be due to medicines. The aim of this study was to review all reports of suspected adverse drug reactions (ADRs) in the SEFV-H database derived from the gender-affirming hormone therapy (GAHT). For this purpose, we consulted the Andalusian Centre for Pharmacovigilance (CAFV) and used three search algorithms to select only those reports derived from hormone therapy used by trangender people. A total of 21 reports were obtained, 13 corresponding to masculinizing therapy with testosterone and 8 corresponding to feminizing therapy with estradiol and cyproterone acetate. Most of these reports were of non-serious symptoms. Skin and subcutaneous tissue disorders, neoplasms, and psychiatric, vascular, gastrointestinal, and nervous system disorders were the most common suspected ADRs. The median age was 23.6 years for masculinizing therapy and 27 years for feminizing therapy. These data highlight the need for well-designed studies specifically focused on transgender people undergoing hormone therapy. Such studies are essential to develop evidence-based treatment guidelines tailored to this population and to provide accurate, population-specific information about the potential health risks associated with gender-affirming hormone use.