Alendronate, known popularly as Fosamax, is used to reduce bone loss, increase bone density and reduce the risk of spine, wrist and hip fractures in postmenopausal women. Bisphosphonates are the most commonly used treatment for postmenopausal osteoporosis.
The initial study was named the Fracture Intervention Trial or FIT, and its results were reported in 1996 and 1998.
The follow-up study now being reported is known as FLEX, for FIT Long-Term Extension. It was designed to evaluate the effects on BMD for a total of 10 years, comparing those who continued to take the drug with those who stopped after five years. A total of 1,099 women who had previously received alendronate in FIT and afterwards, were re-randomized to receive placebo or alendronate at 5 mg or 10 mg daily.
According to Black, findings showed that "women randomized to continue taking alendronate did maintain a higher BMD at the hip and spine than those randomized to placebo. For those who stopped, there was a modest loss of BMD, but not a dramatic loss."
The study found differences in bone loss in those who continued versus those who stopped but the differences were surprisingly modest and there were no differences in rates of non-spine fractures or in spine fractures as assessed by comparison of spine x-rays. Severe spine fractures associated with painful symptoms were lower in those who continued but were relatively rare overall (5 percent in those who discontinued vs. 2.5 percent among those who continued drug treatment).
In the United States, osteoporosis affects about 44 million people age 50 and older, and of these, 80 percent are postmenopausal women.
According to Black, "Older people are often taking several different medications. But for many women, if they can discontinue one treatment after five years, it would also be a welcome lifestyle change and will decrease their overall costs for medical care."
A typical regimen requires the patient to drink a full glass of water with the drug on an empty stomach and sit upright for up to 30 minutes.
While the results suggest discontinuation of the treatment for some women, women at a very high risk of clinical spine fractures may benefit by continuing beyond five years, according to Black.
"In the future, we hope to be able to more specifically identify people who should continue and who should stop."
