Alendronate sodium prevents bone loss in postmenopausal women who stop hormone replacement therapy

Recently in the United States, the National Institutes of Health ended early one arm of the Women's Health Initiative, the nation's largest study of a type of hormone replacement therapy (HRT), saying that long-term use of combined estrogen and progestin significantly increased the women's risk of breast cancer, heart attacks and stroke. As a result of this action, many women may discontinue use of HRT and experience a period of rapid bone loss, similar to that seen after menopause.

"Women who discontinue HRT will lose the bone-health benefits of the drug as soon as they stop taking it," said Lorraine A. Fitzpatrick, MD, and Professor of Medicine at The Mayo Clinic, Rochester, MN. "Loss of bone mass can lead to osteoporosis and result in debilitating fractures of the hip and spine. Women who want to protect the strength of their bones should talk to their doctor about the effective alternatives that are available."

Alendronate sodium protected bones from rapid bone loss
In a study of postmenopausal women who recently had discontinued HRT, alendronate sodium, a non-hormonal therapy for osteoporosis, prevented bone loss and significantly (p<0.001) increased bone density of the spine and hip. This multicenter, international, double-blind 12-month study titled "Alendronate reverses the bone loss associated with discontinuation of hormone replacement therapy", published in 1999 and presented at the European Symposium on Calcified Tissues, evaluated the efficacy and safety profile of alendronate as compared to placebo (sugar pill) in postmenopausal women with low bone mass who had discontinued HRT within three months prior to randomization. A total of 144 women were randomly assigned to either placebo (n=49) or alendronate once daily dosing (n=95) for 12 months. Both groups received a calcium supplement daily, which is recommended practice in osteoporosis management. Study endpoints included bone mineral density (BMD) of the spine, hip and total body, biochemical markers of bone turnover, and tolerability. Results showed that women on placebo experienced rapid bone loss at the spine (p< 0.001) while women treated with alendronate had significant (p<0.001) increases in bone mass at the spine, hip and total body, as measured by BMD. Alendronate was well tolerated with no increase in adverse events compared to placebo.

About osteoporosis
Menopause is a key factor contributing to the development of osteoporosis, which is caused when there is an imbalance in bone-building cycles and more bone is broken down than is replaced. Bone loss can lead to osteoporosis, a disease that causes bones to become more porous, gradually making them weaker, more brittle and prone to fracture.

Approximately 200 million women worldwide suffer from osteoporosis, which afflicts an estimated one-third of women aged 60 to 70. The effect on quality of life for those who suffer osteoporotic fractures can be catastrophic. Fractures of the hip almost always require hospitalization and often results in a loss of mobility and independence. Half of those who suffer hip fractures lose the ability to walk independently, and up to one-third become completely dependent. Hip fractures also are associated with increased mortality.

"This is an important issue for women who are discontinuing HRT," said Dr. Fitzpatrick. "If a woman wants to prevent or treat thinning bones, she should use a drug designed specifically for osteoporosis. Before stopping HRT, women should talk to their doctor about medications that will prevent future fractures."

Alendronate sodium
Introduced in 1995 for the treatment of postmenopausal osteoporosis, alendronate sodium is the number one prescribed bisphosphonate treatment for osteoporosis worldwide.1 The first oral medication available in a once-weekly dosing regimen for the treatment of osteoporosis, alendronate is the only therapy shown to consistently reduce the risk of fractures at the hip and spine. More than 10 years of clinical studies have shown that alendronate is effective and well-tolerated.

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