[Mechanisms of action in bisphosphonates]

Bisphosphonates have the high affinity to hydroxyapatites and act as the inhibition of bone resorption in a low dose, while they act as the inhibition of the calcification in a high dose. In tissues, bisphosphonates adsorbing bone surface become detached by a low pH environment with bone resorption and then act on osteoclasts. In cellular events, nitrogen-containing compounds interfere with protein prenylation by inhibiting an enzyme in the HMG-CoA reductase pathway. On the other hand, non-nitrogen-containing bisphosphonates act by producing toxic analogs of ATP that cause cell death.