Bisphosphonate drug clodronate

Bisphosphonates structurally mimic endogenous pyrophosphate, which inhibits precipitation and dissolution of bone minerals. They retard bone resorption by osteoclasts and, in part, also decrease bone mineralizatioa Indications include tumor osteolysis, hypercalcemia, and Paget s disease. Qinical trials with etidronate, administered as an intermittent regimen, have yielded favorable results in osteoporosis. With the newer drugs clodronate, pamidronate, and alendronate, inhibition of osteoclasts predominates a continuous regimen would thus appear to be feasible. 

Figure 2 Effect of liposomal formulations BPs (alendronate and clodronate), empty and free drugs on RAW 264 cell survival. Curves represent percentage of cell inhibition with different BP concentrations. Cell count in buffer only was determined to be 100% (n = 3). Abbreviation BPs, bisphosphonates. Source From Ref 69.

Finally, bisphosphonates have an important place in treatment of osteoporosis of all causes, including steroid-induced osteoporosis. Disodium etidronate, alendronate and clodronate all have potent effects to restore bone mass, and this effect persists for several years of therapy. Newer drugs such as zoledronic acid can be administered by infrequent (once-yearly) infusion, which can help compliance and reduce side effects. 

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