Bioidentical hormone replacement therapy

This MedLibrary.org supplementary page on Bioidentical hormone replacement therapy is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:

Related Sponsors

BM Pharmacy Generic pharmaceuticals at unbeatable prices. Insomnia, men's health, hair health, pain control. bmpharmacy.com
Online Pharmacy Carisoprodol, tadalafil, sildenafil, vardenafil and more... xlpharmacy.com
MedBasket.com Discreet. Inexpensive. Fast shipping. Great selection. What more can we say? medbasket.com
Frugalmed 2000 reasons to shop with us first. frugalmed.com
Ads by Tiva

 The neutrality of this article is disputed.
Please see the discussion on the talk page. (December 2007)
Please do not remove this message until the dispute is resolved.

"Bioidentical" hormone replacement therapy (BHRT) is the use of supplemental doses of steroid hormones with a chemical structure identical to endogenous human hormones (hormones naturally produced in the human body). Generally BHRT is prescribed to relieve the symptoms of menopause, though more recent therapies promise anti-aging effects and possible deferral of the diseases of aging. BHRT differs from conventional hormone replacement therapy, which by definition uses animal or synthetic hormones whose structures are similar or identical to those produced in the human body.

In early 2008 U.S. Food and Drug Administration (FDA) sent letters warning seven pharmacies that the claims they make about the safety and effectiveness of the BHRT products they sold are unsupported by medical evidence, and are considered false and misleading by the agency.1 The FDA expressed concern that unfounded claims made about BHRT mislead women and health care professionals.

Contents

Overview

The term "bioidentical" denotes hormones that are chemically synthesized so as to be identical to the endogenous hormones of the human body: estradiol, estrone, estriol, progesterone, and testosterone. The disadvantage of this strategy (and the subsequent necessity of synthetic hormones in medical practice) is that none of the endogenous hormones have sufficient bioavailability when taken in the form of a tablet. Only 17-hydroxylated steroids remain intact following the hepatic first pass effect when administered orally. The molecular structures of bioidentical hormones are not patentable because patents can only be obtained for novel items, not pre-existing natural substances. Such hormones have become commercially profitable in some cases, particularly when it has been possible to patent some other aspect of their production such as their mechanism of delivery (such as the matrix delivery system of the estradiol patch). Trials to conclusively establish the apparent advantages of bioidentical hormones have not been conducted. It is doubtful such trials will ever be conducted unless through governments or the proponents of this therapy.

Action

Non-bioidentical synthetic progesterone analogues (called progestins) have actions similar or identical to the hormone progesterone, but progestins are a suspected human carcinogen.2 Estrogens in general have been declared to be known carcinogens.3 Bioidentical hormone replacement therapy has received considerable attention since the results of the Women's Health Initiative were published, which suggested Premarin and progestins had significant cancer and clot-inducing properties. When these results were publicised, the use of Premarin and progestins plummeted. The apparent advantages of bioidentical hormones have been promoted by, among others, the actress Suzanne Somers.4

Potential advantages

  • Emphasis on topical administration; avoids problems such as blood clotting that are caused by the hepatic metabolism of orally administered hormones 5
  • Progesterone may work differently in the body than medroxyprogesterone acetate6
  • Individualized compounded doses may be prescribed, rather than "one dose fits all" approach of conventional hormone replacement therapy7 Conventional hormone replacement therapy is also available in a wide range of dosages and dosage forms.
  • Theoretically, inclusion of estriol may be protective against hormone-induced cancer. Unlike estradiol, estriol binds preferentially to the second estrogen receptor (ERbeta). ERbeta may function as a tumor suppressor.8 Estriol is not approved for human use by the FDA, who considers the term "bio-identical" to be non-scientific.9

Patentable drugs are extensively tested. In the absence of similar testing, the potential benefits of BHRT remain unconfirmed. BHRT may present risks for breast cancer similar to those posed by conventional HRT.8 A pilot study conducted by the U.S. National Institutes of Health indicated that the risks of blood clotting and strokes that arise with Premarin and PremPro are lower with bioidentical esterified estrogens, in women with variations of their clotting systems which make them prone to clots.10 Oral conjugated equine estrogens (Premarin) were found to be associated with increased venous thrombotic risk. The study found that users of esterified estrogen had a lower venous thrombotic risk than those using conjugated estrogens.

Basics

 This article does not cite any references or sources.
Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (February 2007)

Bioidentical hormone replacement therapy is used to help treat the symptoms of menopause, perimenopause, and post-menopause. Treatment with bioidentical hormones is theoretically based on creating a unique cocktail of hormones for the individual patient, based on hormone deficiencies identified via saliva samples,an approach that is "in direct contradiction to evidence-based guidelines which support tailoring hormonal therapy individually, according to symptoms".11 These are often referred to as "custom-compounded" hormone products. The doses are individualized, and the mixture of products may not be commercially available.citation needed However, although some of the estrogen and/or progestogen components are FDA approved, the mixtures themselves are not, as they have not been studied to confirm that they are absorbed appropriately or provide predictable levels in blood and tissue.12 The entire concept has been criticised as a marketing scheme with no scientific basis.13

Bioidentical hormones, sometimes referred to as natural hormones, are those that are molecularly identical to the hormones that are produced in the body. Hormones and steroids are taken from plants and animals and altered to be identical in molecular structure, then put into a form that can be absorbed by the body: cream, oral, suppository or injections. The plants that the hormones are extracted from are soycitation needed and yams, while the animals are pigs or horses. The plant hormones are chemically altered to become molecularly identical to the ones humans produce, as plants do not produce estrone, estriol, estradiol, progesterone, or testosterone..

The FDA recognizes pharmacy compounding of BHRT products when the product conforms to a licensed practitioner’s decision that an FDA-approved drug does not meet the patient's needs, but the FDA is concerned that claims about BHRT products are false and misleading.14 Some bioidentical hormones are FDA approved.15 Others, such as Estriol, are not approved for human use by the FDA.9 Compounding pharmacies were warned by the FDA to stop using the "non-scientific" term "bio-identical" in 2008, a warning supported by The Endocrine Society and the American Association of Clinical Endocrinologists.16

Individually-compounded mixtures have not been approved by the FDA, and by their very nature are not susceptible to FDA approval. Consequently, they are untested for purity, potency, efficacy or safety, and some may contain unknown contaminants. Estrogen and progesterone are available in FDA-approved forms - estradiol derived from soy or yam sources is found in some approved medications.17

Wiley Protocol

Main article: Wiley Protocol

The Wiley Protocol is a controversial type of compounded BHRT that is endorsed by T. S. Wiley and actress Suzanne Somers. Others have sharply criticized it.18192021

Footnotes

  1. ^ "FDA Takes Action Against Compounded Menopause Hormone Therapy Drugs". U.S. Food and Drug Administration (2008-01-09). Retrieved on 2008-10-20.
  2. ^ International Agency for Research on Cancer (1998-03-03). "Progestins as carcinogens". Retrieved on 2007-08-27.
  3. ^ Stephenson, J (2001). "Estrogen as a carcinogen". JAMA 285: 284-c. doi:10.1001/jama.285.3.284-c. 
  4. ^ Somers, Suzanne (2004). The sexy years: discover the hormone connection: the secret to fabulous sex, great health, and vitality for women and men. New York: Crown Publishers. ISBN 0-609-60721-9. 
  5. ^ Scarabin, PY; Oger E, Plu-Bureau G (2003). "Differential association of oral and transdermal oestrogen-replacement therapy with venous thromboembolism risk". Lancet 362: 428–32. doi:10.1016/S0140-6736(03)14066-4. PMID 12927428. 
  6. ^ Simoncini, T; Mannella P, Fornari L, Caruso A, Willis MY, Garibaldi S, Baldacci C, Genazzani AR. (2004). "Differential signal transduction of progesterone and medroxyprogesterone acetate in human endothelial cells". Endocrinology 145 (12): 5745–56. doi:10.1210/en.2004-0510. PMID 15358673, http://endo.endojournals.org/cgi/content/full/145/12/5745. 
  7. ^ Romero, M (2002). "Bioidentical hormone replacement therapy. Customizing care for perimenopausal and menopausal women". Advance for Nurse Practitioners 10 (11): 51–2. PMID 12478948. 
  8. ^ a b Bardin, A; Boulle N, Lazennec G, Vignon F, Pujol P (2004). "Loss of ERbeta expression as a common step in estrogen-dependent tumor progression". Endocrine-Related Cancer 11: 537–51. doi:10.1677/erc.1.00800. PMID 15369453. 
  9. ^ a b Peck, Peggy. "FDA Cracks Down on Bio-Identical Hormones from Compounding Pharmacies" (web article). MedPageToday. Retrieved on 2008-01-11.
  10. ^ Smith, N.; Heckbert, S.R., Lemaitre, R.N., Reiner, A.P., Lumley, T., Weiss N.S., Larson, E.B., Rosendaal, F.R. & Psaty, B.M. (2004). "Esterified estrogens and conjugated equine estrogens and the risk of venous thrombosis". JAMA 292 (13): 1581–1587. doi:10.1001/jama.292.13.1581. PMID 16973976. 
  11. ^ Cirigliano M (June 2007). "Bioidentical hormone therapy: a review of the evidence". Journal of women's health (2002) 16 (5): 600–31. doi:10.1089/jwh.2006.0311. PMID 17627398. 
  12. ^ North American Menopause Society. "Custom-compounded hormone products". Retrieved on 2007-08-27.
  13. ^ Kalvaitis, Katie. "Compounded hormone therapies: unproven, untested - and popular.(Endocrine Today 6(5) March 25, 2008)" (web reprint). Retrieved on 2008-03-25.
  14. ^ "Statement of Steven K. Galson, M.D., M.P.H., Director, Center for Drug Evaluation and Research, U.S. Food and Drug Administration before Senate Special committee on Aging, "Bio-Identical Hormones: Sound Science or Bad Medicine"". FDA (April 19, 2007). Retrieved on 2007-12-01.
  15. ^ "What are bioidentical hormones?". Harvard Health Publication, Harvard Medical School (August 2006). Retrieved on 2007-12-01.
  16. ^ Frieden, Joyce. "FDA Cracks Down on Bioidentical Hormones" (web reprint). Retrieved on 2008-03-05.
  17. ^ Mayo Clinic (2007-08-21). "Bioidentical hormones: Are they safer?". Retrieved on 2007-08-27.
  18. ^ Ellin, Abby (October 15, 2006). "A Battle Over ‘Juice of Youth’", New York Times. Retrieved on 1 December 2007. 
  19. ^ Sherr, Lynn and Glenn Ruppel (February 16, 2007). "Suzanne Somers: Super Saleswoman: Has Somers Found the Fountain of Youth?". ABC News, 20/20. Retrieved on 2007-12-01.
  20. ^ "A Real Somers Storm: At war over Suzanne Somers's book on 'bioidenticals'", Newsweek (November 13, 2006). Retrieved on 1 December 2007. 
  21. ^ Patricia Yarberry Allen (2007-01-12). "Ask Dr. Pat: Bioidentical Hormones". Retrieved on 2007-05-04.

References

External links

Wikipedia content modification information:

  • This page was last modified on 25 October 2008, at 11:25.

Wikipedia Authorship and Review

Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.

Wikipedia Usage Guidelines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Bioidentical hormone replacement therapy".

The URL for this specific entry is:

All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.