Aprela ®
What a lovely sounding name.
According to Wyeth, Aprela® is a combination of CEEs (Premarin®) with a selective estrogen receptor modulator (SERM) called bazedoxifine (BZA), also known as Viviant®.[11] Aprela® is categorized as a tissue-selective estrogen complex (TSEC) and has been evaluated for the effects on menopausal symptoms, metabolic parameters and overall safety during a 2-year double-blind, placebo- and active-controlled trial involving healthy postmenopausal women (age 40-75 years).[12]
Dosages used in the study comprised BZA at 10, 20, or 40 mg in combination with CEEs of 0.625 or 0.45 mg – the mid-range dosages of Premarin®.
The overall strategy for the combination drug is a proven concept but not without issues. SERMs function to selectively stimulate or inhibit estrogen receptors in various tissues (e.g. breast tissue) in that they either stimulate cell proliferation (i.e. estrogen active) or inhibit it (i.e. estrogen inactive).[13]
Tamoxifin was the first SERM to be studied for its capacity to block the action of estrogen in breast cells effectively inhibiting cell proliferation and therefore useful in treating breast cancer. However, Tamoxifin has the serious side effect of increasing the risk of uterine cancer as it mimics the actions of estrogen and stimulates cell proliferation in the uterus.[14]
This concept was further explored with the combination estrogen-progestin therapies Prempro® and Premphase®. Studies in the 1980s suggested that the progesterone hormone tended to counteract the increased risk of uterine cancer. Oops! As the public well knows, this combined HRT resulted in increased risks of breast cancer, strokes, heart attacks and blood clots. Wyeth continues to battle thousands of lawsuits related to Prempro®.
So how will Aprela® (BZA + CEEs) compare and is it safer? It certainly does nothing for the suffering and cruelty the horses must endure.
BZA (Viviant®) is a novel selective estrogen receptor modulator (SERM) specifically developed to help prevent postmenopausal osteoporosis. In combination with CEEs, it is anticipated that it will alleviate the symptoms of menopause as well as increase bone mass density (BMD) without causing stimulation of breast and uterine tissues – the ideal solution? At least that is the conjecture.
While it is true that a 2-year clinical phase III trial has taken place and appears to have been effective for menopausal vasomotor symptoms, while at the same time increasing BMD, available data are very limited, optimal dosages are unclear and detailed information on long-term efficacy or side effects are unknown. Moreover, it is well known that cancers are insidious and can typically take 10 years or more to develop. Isn’t that what happened with ALL of the Premarin® family of drugs – not just the combination Prempro® therapy? As far back as the 1970’s there was damaging evidence about the risk of cancers and cardiovascular disorders using CEEs, long before the arrival of Prempro® in 1995 and finally the WHI which undisputedly linked HRT with increased cancer and cardio risks among others.
And bazedoxifene itself is not without issues. Clinical trials have indicated a higher incidence of deep vein thrombosis, retinal thrombosis, hot flushes and leg cramps compared with placebo-treated subjects. In fact, bazedoxifene has garnered two approvable letters from the FDA, but concerns about the increased risk of stroke and thromboembolic events have contributed to a delay for this drug.[15] Initially to be released in 2009, it still awaits approval from the FDA as does Aprela®, slated to be launched in 2011.
Conclusion
Isn’t it time for a change given the serious risks of CEEs and the unknown risks of Aprela®? Will we have to wait for another decade or more to realize yet again, we have been duped by Big Pharma while in the interim thousands of women and horses suffer at the hands of these insipid gluttons?
Why not genetic engineering? Yes, perhaps a frightening word to some, but these techniques afford the promise of liberating our dependence on many animal-derived products and advance the ethical objective of humane animal treatment.
Examples of recombinant DNA products include the production of synthetic human insulin using modified bacteria and the thyroid stimulating hormone (TSH) both of which were once derived from animal sources only. The human gene that codes for either the insulin or thyroid hormone is inserted into the genetic material of bacteria (RNA) and the bacteria grow and manufacture the hormone which can then be purified and used medically. The advantage of these techniques is that the cloned material is an exact replica of the human component hence perfectly compatible with human tissue without risks of serious contraindications.
Imagine now if human estrogens could be produced in the same manner; I believe they can be. All the suffering of the mares and foals would be resolved, postmenopausal women would have fewer uncertainties about the risks of HRT and Big Pharma would still be raking in the big bucks albeit not at the expense of the innocent.
Perhaps the future will beget good fortune but in the mean time we need to be vigilant about the introduction of this new CEE toxin with the pretty name – Aprela®. No doubt Wyeth’s marketing strategy will be a clever disguise to underplay any uncertainties associated with the estrogen derivatives of PMU, while promoting the benefits of the osteoporosis therapy component. Business ethics seemingly do not apply to Big Pharma as we have seen time and time again.
————————————-
SOURCES
[1] http://www.holisticonline.com/Remedies/hrt/hrt_estrogen.htm
[2] http://rx4u.com/natural%20hormones.htm#ESTRIOL%20%28E3%29
[3] http://raypeat.com/articles/articles/tissue-bound-estrogen.shtml
[4] See 3.
[5] See 3.
[6] http://www.cancer.gov/cancertopics/understandingcancer/estrogenreceptors/allpages/print
[7] See 6.
[8] http://www.project-aware.org/Managing/Hrt/PremarinFacts_Opinion.shtml
[9] http://www.rxlist.com/premarin-drug.htm
[10] http://www.goodpharma.com/estrogen.htm
[11] http://www.ncbi.nlm.nih.gov/pubmed/20336595?dopt=Abstract
[12] http://www.ncbi.nlm.nih.gov/pubmed/19635615
[13] See 6.
[14] See 6.
[15] medco.mediaroom.com/file…/2009+DRUG+TREND+REPORT.pdf
© Int’l Fund for Horses
