Bisphosphonate
![Chemical structure of pyrophosphate (A, above) and bisphosphonates (B, below). P = phosphorus, O = oxygen, H = hydrogen, C = carbon, R = side chain. In bisphosphonates, the central oxygen atom is replaced with a carbon atom. All bisphosphonates share a common phosphorus-carbon-phosphorus motif with two side chains (R1 and R2 in the figure). The R2 side chain determines the chemical properties of the drug, and distinguishes individual types of bisphosphonates. This chemical structure affords a high affinity for calcium hydroxyapatite, allowing for rapid and specific skeletal targeting.](/Images/godic/202412/24/Bisphosphonate_structure1335.jpg")
![](/Images/godic/202412/24/Bisphosphonate_side_chains1335.png")
![HMG-CoA reductase pathway](/Images/godic/202412/24/HMG-CoA_reductase_pathway1335.png")
Bisphosphonates are a class of drugs that prevent the loss of bone mass, used to treat osteoporosis and similar diseases. They are the most commonly prescribed drugs used to treat osteoporosis. They are called bisphosphonates because they have two phosphonate (PO(OH)
2) groups.