Oral vs transdermal estrogen therapy: Is one preferable regarding sexuality?
Taylor HS, Tal A, Pal L, et al. Effects of oral vs transdermal estrogen therapy on sexual function in early post menopause: ancillary study of the Kronos Early Estrogen Prevention Study (KEEPS). JAMA Intern Med. 2017;177(10):1471-1479.
If route of administration of systemic HT influences sexuality outcomes in menopausal women, this would inform how we counsel our patients regarding HT.
Recently, Taylor and colleagues conducted a randomized clinical trial to examine the effects of HT's route of administration on sexual function.8 The 4-year Kronos Early Estrogen Prevention Study (KEEPS) ancillary sexual study randomly assigned 670 recently menopausal women to 0.45 mg of oral conjugated equine estrogens (CEE), an 0.05-mg estradiol transdermal patch, or placebo (with oral micronized progesterone for those on active treatment). The participants were aged 42 to 58 years and were within 36 months from their last menstrual period.
Participants were evaluated using the Female Sexual Function Inventory (FSFI) questionnaire, which assessed desire, arousal, lubrication, orgasm, satisfaction, and pain. The FSFI is scored using a point range of 0 to 36. A higher FSFI score indicates better sexual function. An FSFI score less than 26.55 depicts low sexual function (LSF).
Transdermal estrogen improved sexual function scores
Treatment with oral CEE was associated with no significant change in FSFI score compared with placebo, although benefits were seen for lubrication. By contrast, estrogen patch use improved the FSFI score (mean improvement, 2.6). Although improvement in FSFI score with transdermal estrogen was limited to participants with baseline LSF, most participants in fact had LSF at baseline.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
Oral estrogen increases the liver's production of sex hormone-binding globulin, resulting in lower free (bioavailable) testosterone. Transdermal estrogen does not produce this effect. Accordingly, sexuality concerns may represent a reason to prefer the use of transdermal as opposed to oral estrogen.