Tiludronic Acid
Tiludronate, or (4-chlorophenyl)thio-methylene-1,1-bisphosphonate, is a first generation bisphosphonate similar to [etidronic acid] and [clodronic acid]. These drugs were developed to mimic the action of pyrophosphate, a regulator of calcification and decalcification. Tiludronic acid was first described in the literature in 1988 as a potential treatment for Paget's disease of bone.  Tiludronic acid was granted FDA approval on 7 March 1997.