48. Estrogens, Estrogen Agonists/Antagonists, and Calcitonin

  1. Clifford J. Rosen MD
  1. Nelson B. Watts

Published Online: 19 JUL 2013

DOI: 10.1002/9781118453926.ch48

Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, Eighth Edition

Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, Eighth Edition

How to Cite

Watts, N. B. (2013) Estrogens, Estrogen Agonists/Antagonists, and Calcitonin, in Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, Eighth Edition (ed C. J. Rosen), John Wiley & Sons, Inc., Ames, USA. doi: 10.1002/9781118453926.ch48

Publication History

  1. Published Online: 19 JUL 2013

ISBN Information

Print ISBN: 9781118453889

Online ISBN: 9781118453926

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Keywords:

  • calcitonin;
  • estrogen agonists;
  • estrogen antagonists;
  • osteoporosis

Summary

It is well established that osteoporosis is more common in women than men and fracture risk increases dramatically after menopause. Several different forms of estrogen are available for therapeutic use (e.g., estradiol, conjugated estrogen, esterified estrogens) as well as several routes of administration (e.g., oral, transdermal). Tamoxifen and functionally related compounds are classified as estrogen agonists/antagonists, and bind with estrogen receptors, activating estrogen pathways in some tissues and blocking them in others. However, several estrogen agonists/antagonists have fallen by the wayside, while a few have made it into Phase 3 trials for osteoporosis. In humans, calcitonin is a 32-amino acid peptide produced by specialized C cells in the thyroid. Osteoclasts express receptors for calcitonin and respond to calcitonin with a rapid decrease in resorptive capacity. An oral form of calcitonin is being studied as possible treatment for osteoarthritis and osteoporosis.