Five Years of Fosamax: Enough of a Good Thing?

The 10-year half-life of the bisphosphonate alendronate suggests that its efficacy might persist after discontinuation. To compare the effects of discontinuing alendronate after 5 years versus continuing for a total of 10 years, investigators randomized 1099 women who had already received alendronate for 5 years in the Fracture Intervention Trial (FIT) (Journal Watch Women’s Health Feb 1 1999) to either continue alendronate (5 mg/day or 10 mg/day) or receive a placebo for an additional 5 years, in the FIT Long-term Extension (FLEX) trial. Study endpoints included changes from baseline BMD (as measured at FLEX entry), changes in biochemical markers of bone turnover (measured at both FIT and FLEX entry; increases in markers indicate increases…