Risk of venous thromboembolism by route of administration of estrogen

Bioidentical menopausal hormone therapy: registered hormones (non-oral estradiol ± progesterone) are optimal

The many advantages of registered bioidentical sex hormones over registered, conventional, non-bioidentical menopausal hormone therapy (MHT) are considered. The transdermal route of estrogen administration avoids excess venous thromboembolic and ischemic stroke events. There is some indication that conjugated equine estrogens are more thrombogenic and most likely induce some hypertensive responses; estradiol might also be superior to conjugated equine estrogens (CEE) in terms of global cardiovascular health. The most valid evidence presently suggests that CEE-only treatment does not increase the risk of breast cancer and even may reduce it. But its combination with a synthetic progestogen (mainly medroxyprogesterone acetate) is a critical issue since it seems to be primarily associated with an increased incidence of breast cancer, however similar to or lower than that associated with some common lifestyle factors. Though not yet proven in a randomized, controlled trial, MHT continuously combining oral micronized progesterone with transdermal estradiol can presently be considered as the optimal MHT. It is not only safer than custom-compounded bioidentical hormones but also than oral conventional MHT and has the best breast profile; registered products for such optimal MHT are available around the world and must be preferred.

Hormone therapy and the risk of stroke: perspectives 10 years after the Women's Health Initiative trials

Principal findings on stroke from the Women's Health Initiative (WHI) clinical trials of hormone therapy indicate that estrogen, alone or with a progestogen, increases a woman's risk of stroke. These results were not unexpected, and research during the past decade has tended to support these findings. Consistent evidence from clinical trials and observational research indicates that standard-dose hormone therapy increases stroke risk for postmenopausal women by about one-third; increased risk may be limited to ischemic stroke. Risk is not modified by age of hormone initiation or use, or by temporal proximity to menopause, and risk is similar for estrogen plus progestogen and for unopposed estrogen. Limited evidence implies that lower doses of transdermal estradiol (≤50 μg/day) may not alter stroke risk. For women less than 60 years of age, the absolute risk of stroke from standard-dose hormone therapy is rare, about two additional strokes per 10 000 person-years of use; the absolute risk is considerably greater for older women. Other hormonally active compounds - including raloxifene, tamoxifen, and tibolone - can also affect stroke risk.