Original Research
Tuesday, October 15, 2024
08:30 AM–10:00 AM
Abstract
Introduction:
While recommendations are available for subcutaneous (SC) testosterone administration for masculinizing gender-affirming hormone therapy (GAHT) in transgender and non-binary patients, there is limited literature regarding the efficacy differences between SC and intramuscular (IM) estradiol (E2) administration for feminizing GAHT. In many practices including at the study institution, the SC route is frequently used off-label for feminizing GAHT for improved injection comfort and ease.
Research Question or Hypothesis:
The purpose of this study was to compare SC versus IM E2 administration to determine if there are differences in time to therapeutic levels.
Study Design:
This single health-system, retrospective cohort study included all patients = 18 years prescribed SC or IM E2 valerate with 2 or more serum E2 levels at least 3 months apart and a documented diagnosis of gender incongruence who were seen at University Health between January 1, 2013 to December 31, 2023.
Methods:
The primary endpoint was percentage of patients reaching therapeutic E2 levels at month 6. Secondary endpoints included occurrence of sub- and supra-therapeutic E2 levels; SC and IM E2 levels at 3, 6, 9, and 12 months; and percentage of patients who received pharmacist-led injection education. Continuous data were analyzed via a Wilcoxon test and categorical data were analyzed via chi-squared and Fisher’s exact tests.
Results:
Forty-five patients met inclusion criteria. Results of the primary endpoint showed no statistical difference (p=0.59) in time to therapeutic levels between SC (25.9%) and IM (33.3%) E2 administration. There was also no statistical difference in secondary endpoints of therapeutic levels at any time frame between routes.
Conclusion:
Although study results support the use of SC E2 administration, larger studies comparing E2 administration routes are needed to align GAHT guidelines with current practice.
Presenting Author
Jordan Rowe PharmD, BCACP, BC-ADMUMKC School of Pharmacy
Authors
Mary Beth Dameron PharmD
Kansas City VA Medical Center
Abby Poage PharmD
University Health
Andrew Smith PharmD, BCPS, BCCP, FCCP
UMKC School of Pharmacy