Prolia – A Different Antiresorptive
Prolia (Denosumab) is the newest type of Antiresorptive medication for Osteoporosis. Like the other Antiresorptive medications, Prolia slows down the cells that eat away bone, but in a different way. A simple way of looking at Prolia is to think of it as “birth control” for the cells that eat away bone. See my post about “Osteoclasts Gone Wild”.
Prolia mimics the hormone OPG which regulates the hormone RANK-Ligand which forms and activates the Osteoclast cells that eat away bone. Good bone health is based on a balance between OPG and RANK-Ligand. If there is too little OPG, Prolia takes over the role of OPG to bring the system back to better balance.
Prolia is given in a shot under the skin once every 6 months. It is effective for about 6 to 9 months. It is totally gone by 12 months unless another shot is given. It does not accumulate in bone as Bisphosphonates do. Therefore once it is stopped, it is gone. It also has no ill effects on kidneys or digestive tract.
If you are over 80 or have renal disease, and have serious heartburn or reflux disease, Prolia is a good option to preserve the bone you already have. Patients can add calcium to their bones and gain Bone Mineral Density. Of course, for Prolia to work, you must take enough Calcium and Vitamin D.
Liver functions should be normal and Calcium and Vitamin D levels and daily intake must be maintained if you take Prolia. It is important to have any needed dental work done before taking Prolia. After a fracture, you should wait until healing can be seen on x-ray before taking Prolia.
Like all Antiresorptives, Prolia will suppress bone turnover. Prolia had been used briefly in 2 patients with rare cases of Osteonecrosis of the Jaw (ONJ) and Atypical Fractures of the Femur. There is not yet any conclusive evidence that Prolia, or any other Antiresorptive, causes these conditions.
Jay Ginther, MD
2010 / Revised Feb 2011