Patient/caregiver was instructed upon therapeutic uses of tamoxifen as follows:

Breast cancer

• Increased binding of estrogen to the estrogen receptors and the consequent response of proliferation of the breast tissue, is considered to play a significant role in the growth of tumors in the breast tissue.
• Tamoxifen has an antiestrogenic effect on the breast tissue.
• Binding of tamoxifen to the estrogen receptors in the breast tissue progressively modulate these receptors and reduces response of these receptors to estrogen, thus blocking the proliferative action of estrogen on the breast tissue and helping to prevent growth of tumors in the breast tissue.

Osteoporosis

• Binding of estrogen to the estrogen receptors in the bone tissue is considered to play a significant role in maintaining the bone density and prevention of osteoporosis.
• Tamoxifen has an estrogenic effect on the bone tissue.
• Binding of tamoxifen to the estrogen receptors in the bone tissue progressively modulate these receptors and increases response of these receptors to estrogen, thus helping for a proliferative action of estrogen on the bone tissue and helping increase the bone density.
• This action of tamoxifen can be used to prevent osteoporosis and weakening of bones in post-menopausal women.