Another caveat about bisphosphonates

This from Clinical Oncology News:

Bisphosphonates Associated With Microcracks in the Bone

New research has shown that administration of bisphosphonates can, even while it prevents or retards formation of holes in bone, cause microcracks in bone—weakening it and increasing the risk of fractures it was intended to prevent. The mechanism by which this occurs is suspected to be a side effect of suppressing production of osteoclasts (the cells that break down older bone) while not promoting the production of osteoblasts (the cells that form new bone), thus inhibiting the rate of healthy bone “turnover.” (Might this be the reason for “paradoxical” horizontal femoral fractures in patients taking infused bisphosphonates like Zometa/Reclast or even the biologic RANKL inhibitor Prolia/Xgeva)?

Statistics are that there are more microcracks in the bones of those on bisphosphonates who have had fractures than in the bones of those who have had fractures but never taken bone treatments. But there are fewer holes in the bones of the bisphosphonate-takers. The article posits that there might need to be a finite limit to the length of such treatment to avoid reaching the aforementioned “point of diminishing returns” (my description).

Only goes to show you that there is no such thing as a perfect “magic bullet” drug with no downsides—and that as we age, we can’t “fix" one thing without “breaking" something else, leading to a cascade of unfortunate effects.