Thanks BeaR, for explaining, but surely the side effects in the patch are bad enough to affect women too, i can't see they would be much different to the oral side effects
Anyhow we will just have to wait and see
Hi Jaycee,
Absolutely, side effects are a personal experience and, IMHO, 'hormone replacement therapy' is a misleading term, I prefer MHT (menopausal hormone therapy), precisely because there are synthetic non body identical hormones involved. Even when the hormones are body-identical (17 beta estradiol and progesterone) both dose and dosage are very variable and side effects can be debilitating as well. Besides, there are many transgender people on hormonal therapy, so the term can be confusing for statistics purpose.
Regarding the norethisterone quote from the International Menopause Society document
https://www.imsociety.org/manage/images/pdf/2b650ccd4a2e0c63806d82ed2984ed69.pdf'The median year of diagnosis of breast cancer cases from North America (25% of the included data) was 1999, and for the European studies, 2007, with one as early as 1981. With an average use of 10 years of MHT in current users at diagnosis,and 7 years in past users, much of the exposure to MHT preceded the first publication of the Women's Health Initiative study, after which prescribing practices changed substantially. Consequently, virtually all of the included information pertains to MHT formulations and doses known to have adverse breast effects that are no longer recommended. Specifically, the use of the progestogens medroxyprogesterone acetate and norethisterone (norethindrone)is now discouraged because of their known adverse effects, but these account for nearly all of the data for combined estrogen-progestogen therapy included in the paper. The one analysis of data from prospective studies of the effects of different progestogens provides inadequate data to draw conclusions about the effects of the preferred progestogens, progesterone (50 included cases) and dydrogesterone (253 included cases). Additionally, the majority of cases were women who took oral estrogen, which results in high blood levels of the hormone estrone, whereas transdermal therapy does not(2). Estrone is not only the main estrogen produced by postmenopausal women, but levels are higher in overweight/obese women, such that estrone may be a key factor linking obesity with breast cancer.'
Unfortunately they don't say exactly where the data come from, I will check their References and report back. I suspect they are talking about MHT formulations containing HIGH doses of norethisterone, that are now 'discouraged', but still available, not to mention the high dose norethisterone formulations used as contraceptives.
Patches do avoid liver first pass, so they are less likely to present the same side effects of oral formulations, but on the other hand the amount and rate of hormone release can vary in transdermal drug delivery systems depending on the patch technology and skin barrier factors (water and fat content), and we all know that hormonal fluctuations can cause serious effects.
BeaR
