SUN-140 Evaluating Hyperkalemia and Side Effect Related to Spironolactone Use in Transgender Adolescents: A Retrospective Chart Review Study

Abstract Disclosure: R. Kim: None. K. Co: None. C. Zhang: None. C. Chau: None. P. Singh: None. G. Chelvakumar: None. Z. Boulil: None. M. Marinkovic: None. Background: Standards of care for transgender and gender diverse (TGD) people recommend close monitoring of electrolytes in patients using spironolactone, given the risk of hyperkalemia from mineralocorticoid antagonism. We aimed to evaluate the rate of clinically significant hyperkalemia in transgender adolescents assigned male at birth (AMAB) taking spironolactone. Methods: We conducted a retrospective chart review of patients AMAB who were prescribed spironolactone at our Center for Gender Affirming Care (CGAC) at Rady Children’s Hospital (RCH) from September 2012 - August 2023. We assessed the incidence of hyperkalemia and reported side effects related to spironolactone. Results: Of the 223 participants who met the initial inclusion criteria, 180 had at least one follow up appointment with follow up labs completed and were included in the study. Data showed that none of the patients receiving spironolactone at time of follow up visits developed clinically significant hyperkalemia (K level > 5.1 mmol/L). There was only one instance of elevated baseline potassium level, which resolved at the follow up visit (while on spironolactone). Hyperkalemia was not observed in any of the follow up visits. Adverse effects of patients taking spironolactone predominantly included frequent urination, dizziness, and headaches. Conclusion: Current standards of practice recommend frequent potassium monitoring while taking spironolactone. In our study of 180 TGD subjects from RCH receiving gender affirming therapy with spironolactone, we found no evidence of hyperkalemia. This suggests that consistent monitoring of potassium may not be necessary for young, otherwise healthy patients, considering the low incidence of hyperkalemia. Our findings are consistent with reports from other pediatric and adult centers, indicating that potassium testing can be done less often. Our study's limitations, such as its single-center design and retrospective nature, warrant further research to validate these findings and guide clinical practice. Presentation: Sunday, July 13, 2025