Pharmacokinetics and Pharmacodynamics of Oral and Transdermal 17β Estradiol in Girls With Turner Syndrome

Abstract

Context: The type, dose, and route of 17β-estradiol (E2) used to feminize girls with Turner syndrome (TS) is not well established. Objective: The objective of the study was to characterize pharmacokinetics and pharmacodynamics of oral vs. transdermal E2. Setting: The study was conducted at a clinical research center. Subjects: Ten girls with TS, mean age 17.7 ± 0.4 (se) yr and 20 normally menstruating controls (aged 16.8 ± 0.4 yr) participated in the study. Interventions: TS subjects were randomized 2 wk each to: low-dose daily oral (0.5 mg) and biweekly transdermal E2 (0.0375 mg) with 2 wk washout in between or high-dose oral (2.0 mg) and transdermal (0.075 mg), studied for 24 h each. Tandem mass spectrometry E2 and estrone (E1) assays and a recombinant cell bioassay were used. Results: Controls consisted of the following: E2, 96 ± 11 pg/ml (se), E1, 70 ± 7 (mean follicular/luteal). TS consisted of the following: E2, average concentration on low-dose oral, 18 ± 2.1 pg/ml, low-dose transdermal, 38 ± 13, h...