Skeletal Microdamage Stable After First Year

Skeletal microdamage resulting from bisphosphonate therapy may be maximal during the first year of therapy, and not continue to accumulate with longer periods of therapy, as per new research being presented today at the 28th Annual Meeting of the American Society for Bone and Mineral Research (ASBMR).

Bisphosphonates are the most common class of drugs used for the therapy of osteoporosis because of their demonstrated effect on fracture reduction but the occurence rate of microcracks - small cracks in the skeleton - has been shown to increase with bisphosphonate therapy. This has led to some concerns regarding the potential long-term adverse effects of these agents. This study shows that the continued use of alendronate (a bisphosphonate) is not linked to continued accumulation of microdamage.

Matt R. Allen, Ph.D., assistant research professor, and David B. Burr, Ph.D., chairman, both from the Indiana University School of Medicine Department of Anatomy and Cell Biology, Indianapolis, IN, reviewed the effects of alendronate in one-year-old female beagles. The beagles were given oral doses of alendronate at levels comparable to that employed in humans (.2 mg/kg/day) or at five times the clinical dose (1 mg/kg/day) for either 1 year or 3 years.

Scientists found there was no increase in vertebral microcracks after 3 years of alendronate therapy compared to the beagles treated for 1 year. These results suggest that microcrack accumulation is greatest during the early course of alendronate therapy. This is an encouraging sign for long-term safety of these drugs.

ASBMR President-Elect Steve Goldring, M.D., notes: "These findings have important clinical implications with respect to the long-term safety of bisphosphonates in patients with osteoporosis".


Posted by: Mark    Source