Ask the doctor
Q. I’m in my 70s. Over the past 20 years I’ve broken several bones, including a hip. I’ve taken alendronate but continue to lose bone density. My doctor wants to give me Prolia . What is it?
A. Prolia is a brand name of denosumab, a monoclonal antibody that binds to receptors on osteoclasts (cells that break down bone in the rebuilding process) to keep them from developing properly. As a result, bone breakdown slows, increasing bone density.
In one study, denosumab, which is injected every six months, significantly increased bone density in 98 women who had continued to lose bone during therapy with alendronate (Fosamax) or other bisphosphonates. Denosumab has also been shown to be more effective than two other bone-loss drugs in building bone. However, denosumab has been associated with serious, albeit rare, side effects, including inadequate levels of calcium in the blood, bone death in the jaw, and lowered immunity to infection. As a result, denosumab is usually reserved for people at high risk for fractures for whom other bone-loss treatments were ineffective or had intolerable side effects.
Denosumab may be a reasonable option for you. However, you may want to have a thorough discussion of the risks and benefits of this drug with your doctor.
— by Hope Ricciotti, MD, and Hye-Chun Hur, MD, MPH
Editors in Chief, Harvard Women’s Health Watch