An article in the December 27, 2006 issue of the Journal of the American Medical Association reported that the effects of 5 years of treatment with Fosamax (alendronate) were still apparent in postmenopausal women after an additional 5 years of not taking the drug. However, women who continued taking the drug for a total of ten years at doses of 5 or 10 mg per day maintained greater bone mineral density (BMD).

Researchers at the University of California at San Francisco studied over 1000 postmenopausal women who participated in this study. All women had previously taken alendronate in a 5-year study called the Fracture Intervention Trial (FIT Study) that found substantial increases in BMD and reduced fracture risk. The new study, called the Fracture Intervention Trial Long-term Extension (FLEX Study), divided these women into 3 groups: placebo, 5 mg per day alendronate, and 10 mg per day alendronate.

The good news in this study was that the incidence of non-vertebral fractures in women in the placebo group was the same as it was in the treated groups. The bad news was that the placebo group experienced a greater incidence of clinically diagnosed vertebral fractures. The researchers concluded that, “. . . for many women, discontinuation of alendronate after 5 years for up to 5 more years does not significantly increase fracture risk, but women at high risk for clinical vertebral fractures, such as those with vertebral fracture or very low BMD, may benefit by continuing beyond 5 years.”

If you have been taking alendronate for 5 years or longer, you may want to discuss taking a “Fosamax vacation” with your physician. If the mutual decision is to take the vacation, it becomes especially important that you also discuss the potential need for more frequent testing of BMD during the vacation.

Do not take a vacation from all of the nutrition and lifestyle aspects of osteoporosis treatment and prevention. See Current Treatment Options.

Source
Black, Dennis M., et al. “Effects of Continuing or Stopping Alendronate After 5 Years of Treatment.” Journal of the American Medical Association 296 (2006): 2927-37. (See article abstract)