Bioidentical hormone replacement therapy

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Bioidentical hormone replacement therapy (BHRT) is a layperson's term for the treatment of the hormone deficiencies caused by menopause using only molecules that are identical to the endogenous hormones found in the human body. BHRT differs from conventional hormone replacement therapy which includes animal-derived and synthetic molecules that are similar to, but not identical, to the human hormones that would be present in a healthy individual. The primary bioidentical hormones replaced in human females, estradiol and progesterone, are available in both FDA-approved and individualized pharmacy-compounded products.[1]. Much of the criticism of "BHRT" is actually directed against pharmacy-compounded products and certain practices, not against the use of bioidentical molecules per se. "BHRT" is also used more generally to describe the practice of using only bioidentical hormones in the treatment of all hormone deficiencies, not just menopause.

BHRT proponents argue that studies show significant differences between bioidentical and non-bioidentical hormones, and that replacing hormones lost due to menopause not only relieves symptoms but can improve health and quality of life; however this claim is not validated in scientific literature. In addition, the risks of BHRT are not rigorously studied and remain unknown. [2] The actress Suzanne Somers[3] has been a prominent advocate of BHRT in the media.

Contents

[edit] Structure and administration

Bioidentical hormones have the same chemical structure as the hormones produced within the human body. Most bioidentical and non-bioidentical steroid hormones are chemically-synthesized from diosgenin, a cholesterol-like molecule found in plants. One exception is Premarin, which is extracted from the urine of pregnant mares and contains a horse estrogen molecules, some of which are identical to those found in humans, and some of which are found only in horses. Bioidentical hormones are often inaccurately equated with compounded hormones; there are many FDA-approved bioidentical hormone products.[1] Compounded bioidentical hormone products are custom-mixed by a pharmacist for the patient based on a doctor's prescription, often in a delivery vehicle that is not commercially available. Using either type, the practitioner can adjust the dose based on blood tests taken at carefully timed intervals after administration. Some BHRT practitioners use saliva testing to assess pre-treatment hormone levels and to adjust the replacement dose. Most experts believe that there is no evidence that the levels of estradiol and progesterone in the saliva correlate with response to treatment in postmenopausal women.[1]

[edit] Uses

Main articles: Menopause and Hormone replacement therapy (menopause)

Reduced production of estradiol in menopausal women is associated with many symptoms, including hot flashes, vaginal dryness, poor memory, insomnia, and depression. Estrogen replacement has been shown to relieve these symptoms and to slow or partially reverse several medical disorders that are associated with the loss of estradiol, including osteoporosis, atherosclerosis,[4] vaginal atrophy, dementia,[5] and depression.[6] In 2002, the Women's Health Initiative study (WHI) revealed an increase in breast cancer, heart attacks and stroke in older women given conventional hormone replacement therapy (HRT). This resulted in a significant decline in HRT prescriptions. Even before the WHI results, many women were looking for an alternative to conventional HRT that did not involve Premarin extracted from pregnant horses, have unwanted side effects, or treat menopause as an illness rather than a natural part of life.[1] Proponents of BHRT depict it as a more natural alternative to conventional HRT.

BHRT practitioners generally prescribe estradiol transdermally, via a cream, gel or patch. Transdermal estradiol replacement has not been shown to increase the risk of blood clots, while oral estrogens are known to increase clotting risk. [7] Bioidentical hormones are often compounded to adjust the dose and delivery vehicle individually for each patient.[8]

While non-bioidentical hormones cannot be adequately measured in the blood, bioidentical hormones can be tracked precisely with conventional blood tests, which proponents argue is an advantage.[1] Critics of BHRT argue that it is uncertain if there is an ideal blood level of hormones, and that symptom control, not a specific blood level, is the primary goal of treatment.[1]

BHRT practitioners also generally prescribe progesterone for all post-menopausal women, whether they have an intact uterus or not, and try to maintain a certain ratio of estradiol to progesterone. This contrasts with conventional therapy which prescribes a progestin only if the uterus is present. BHRT advocates argue that progesterone, unlike many progestins, may protect women not only from uterine cancer, but also from breast cancer.[2]

[edit] Research

Peer-reviewed assessments of the evidence for and against BHRT point to a lack of consensus, stemming from a dearth of randomized controlled trials. A 2006 literature review concluded that BHRT is "well tolerated, provides symptom relief, and can address many of the health needs as well as the individual preferences of menopausal and perimenopausal women" [1]. A subsequent review (2009) assessed 200 studies and concluded that there was evidence to suggest bioidentical hormones were safer and more effective than synthetic hormones.[9] . It should be noted, however, that while both reviews appeared in peer-reviewed journals, the authors are prominent advocates of BHRT, with potential conflicts of interest. The author of the first review, Deborah Moskowitz, has been associated with a manufacturer of bioidentical hormone preparations [2], while the author of the second is Dr. Kent Holtorf (bio) a prominent natural/bioidentical hormone advocate.

Another 2008 review concluded that there was little evidence to support the use of compounded hormone products based upon saliva testing, and that individualized compounded hormone products have no proven advantage over conventional hormone therapies. [10]

[edit] Regulatory status in the United States

BHRT is not regulated within the United States, though the U.S. Food and Drug Administration has warned several pharmacies about making unsubstantiated claims about its safety and effectiveness.[11] The compounding of bioidentical hormones is regulated by the boards of pharmacies for each state which allows pharmacists to adjust the doses and delivery methods of BHRT according to the doctor's prescription.[8]

[edit] Criticism

The Endocrine Society issued a position statement that bioidentical hormones carry essentially the same risks and benefits as non-bioidentical molecules.[12] The Mayo Clinic states that there is no evidence that pharmacy-compounded BRHT is safer or more effective than conventional hormone replacement, and that some bioidentical hormones are already available in certain FDA-approved products.[13] The North American Menopause Association has stated that compounded bioidentical hormones have not been approved by the FDA, so there is no guarantee of purity, potency, efficacy or safety, and they may contain unknown contaminants.[13] 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.[14] The FDA warns that claims about compounded BHRT products are unsupported by medical evidence, unlike claims made by manufacturers of FDA-approved products.[11] BHRT has been called a "marketing concept" with no scientific backing by the chief medical editor of Endocrine Today.[15][1] The Harvard Women's Health Watch, published by Harvard Medical School, states that the "natural' part of the marketing of BHRT may be a euphemism for "unregulated" rather than safe.[1]

The FDA has taken measures against compounding pharmacies that produce bioidentical hormone products. It sent letters warning seven pharmacies that the claims they were making about the safety and effectiveness of their compounded BHRT products they were selling were unsupported by medical evidence, and were considered false and misleading by the agency.[11] The FDA has also expressed concern that unfounded claims made about BHRT mislead women and health care professionals, but is willing to allow compounding of the products when a licensed practitioner decides that an approved drug does not meet the patient's needs.[16]

[edit] Wiley Protocol

Main article: Wiley Protocol

The Wiley Protocol is a controversial type of compounded BHRT endorsed by T. S. Wiley. It attempts to produce serum levels of estradiol and progesterone that are identical to those of a young woman at the various times throughout the menstrual cycle. In contrast, most bioidentical hormone practitioners instead seek to produce consistent estradiol and progesterone levels that are less than the average levels of a normal menstrual cycle. It has been shown that using serum levels to judge the effects of transdermal progesterone can be misleading.[17] Others have sharply criticized the Wiley Protocol.[18][19][20][21]

[edit] Footnotes

  1. ^ a b c d e f g h "What are bioidentical hormones?". Harvard Women's Health Watch (Harvard Medical School). 2006-08-01. https://www.health.harvard.edu/newsweek/What-are-bioidentical-hormones.htm. Retrieved on 2009-02-27. 
  2. ^ a b Schwartz, E; Holtorp K (2008). "Hormones in Wellness and Disease Prevention: Common Practices, Current State of the Evidence, and Questions for the Future" (pdf). Prim Care Clin Office Pract 35: 669–705. doi:10.1016/j.pop.2008.07.015. PMID 18928825. http://www.hormoneandlongevitycenter.com/nss-folder/pictures/Holtorf-Med-Clinics.pdf. 
  3. ^ 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. 
  4. ^ Christian, RC; Harrington S, Edwards WD, Oberg AL, Fitzpatrick LA (2002). "Estrogen status correlates with the calcium content of coronary atherosclerotic plaques in women". J Clin Endocrinol Metab 87 (3): 1062–7. doi:10.1210/jc.87.3.1062. http://jcem.endojournals.org/cgi/content/full/87/3/1062. 
  5. ^ Zandi, PP; Carlson MC, Plassman BL, Welsh-Bohmer KA, Mayer LS, Steffens DC, Breitner JC (2002). "Hormone replacement therapy and incidence of Alzheimer disease in older women: the Cache County Study". JAMA 288 (17): 2123–9. doi:10.1001/jama.288.17.2123. http://jama.ama-assn.org/cgi/content/full/288/17/2123. 
  6. ^ Rudolph, I (2004). Influence of a continuous combined HRT (2 mg estradiol valerate and 2 mg dienogest) on postmenopausal depression. 7. pp. 301–11. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=15669555. 
  7. ^ Canonico, M; Plu-Bureau G, Lowe GD, Scarabin PY (2008). "Hormone replacement therapy and risk of venous thromboembolism in postmenopausal women: systematic review and meta-analysis". BMJ 31 (336): 1227–31. doi:10.1136/bmj.39555.441944.BE. http://www.bmj.com/cgi/content/full/336/7655/1227. 
  8. ^ a b Romero, M (2002). "Bioidentical hormone replacement therapy. Customizing care for perimenopausal and menopausal women". Advance for Nurse Practitioners 10 (11): 51–2. PMID 12478948. 
  9. ^ Holtorf K (January 2009). "The bioidentical hormone debate: are bioidentical hormones (estradiol, estriol, and progesterone) safer or more efficacious than commonly used synthetic versions in hormone replacement therapy?". Postgrad Med 121 (1): 73–85. doi:10.3810/pgm.2009.01.1949+. PMID 19179815. http://www.hormoneandlongevitycenter.com/nss-folder/pictures/Holtorf-Med-Clinics.pdf. 
  10. ^ Boothby LA, Doering PL (August 2008). "Bioidentical hormone therapy: a panacea that lacks supportive evidence". Curr. Opin. Obstet. Gynecol. 20 (4): 400–7. doi:10.1097/GCO.0b013e3283081ae9. PMID 18660693. 
  11. ^ a b c "FDA Takes Action Against Compounded Menopause Hormone Therapy Drugs". U.S. Food and Drug Administration. 2008-01-09. http://www.fda.gov/bbs/topics/NEWS/2008/NEW01772.html. Retrieved on 2009-02-17. 
  12. ^ "The Endocrine Society- Position Statement: Bioidentical Hormones" (pdf). The Endocrine Society. 2006-10-01. http://www.endo-society.org/advocacy/policy/upload/BH_Position_Statement_final_10_25_06_w_Header.pdf. Retrieved on 2009-02-29. 
  13. ^ a b Mayo Clinic (2007-08-21). "Bioidentical hormones: Are they safer?". http://www.mayoclinic.com/health/bioidentical-hormones/AN01133. Retrieved on 2007-08-27. 
  14. ^ Frieden, Joyce. "FDA Cracks Down on Bioidentical Hormones" (web reprint). http://www.clinicalendocrinologynews.com/article/PIIS1558016408700440/fulltext. Retrieved on 2008-03-05. 
  15. ^ Kalvaitis, Katie (2008-03-25) (web reprint). Compounded hormone therapies: unproven, untested - and popular. 6. Endocrine Today. http://www.endocrinetoday.com/view.aspx?rid=27231. Retrieved on 2009-02-17. 
  16. ^ "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. http://www.fda.gov/ola/2007/hormone041907.html. Retrieved on 2007-12-01. 
  17. ^ Hermann, AC; Nafziger AN, Victory J, Kulawy R, Rocci ML Jr, Bertino JS Jr. (2005). "Over-the-counter progesterone cream produces significant drug exposure compared to a food and drug administration-approved oral progesterone product.". J Clin Pharmacol 45: 614-619 \ url = http://jcp.sagepub.com/cgi/content/abstract/45/6/614. 
  18. ^ Ellin, Abby (October 15, 2006). "A Battle Over ‘Juice of Youth’". New York Times. http://www.nytimes.com/2006/10/15/fashion/15suzanne.html?pagewanted=all. Retrieved on 2007-12-01. 
  19. ^ Sherr, Lynn and Glenn Ruppel (February 16, 2007). "Suzanne Somers: Super Saleswoman: Has Somers Found the Fountain of Youth?". ABC News, 20/20. http://www.abcnews.go.com/print?id=2874767. Retrieved on 2007-12-01. 
  20. ^ "A Real Somers Storm: At war over Suzanne Somers's book on 'bioidenticals'". Newsweek. November 13, 2006. http://www.newsweek.com/id/44568. Retrieved on 2007-12-01. 
  21. ^ Patricia Yarberry Allen (2007-01-12). "Ask Dr. Pat: Bioidentical Hormones". http://www.womensvoicesforchange.org/2007/01/ask_dr_pat_bioi.html. Retrieved on 2007-05-04. 

[edit] External links

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