[{"from": "human", "value": "Describe this molecule. [C][C][Branch1][C][O][Branch1][=Branch2][P][=Branch1][C][=O][Branch1][C][O][O][P][=Branch1][C][=O][Branch1][C][O][O]"}, {"from": "gpt", "value": "The molecule is only found in individuals that have used or taken this drug. It is a diphosphonate which affects calcium metabolism. It inhibits ectopic calcification and slows down bone resorption and bone turnover.  Bisphosphonates, when attached to bone tissue, are absorbed by osteoclasts, the bone cells that breaks down bone tissue. Although the mechanism of action of non-nitrogenous bisphosphonates has not been fully elucidated, available data suggest that they bind strongly to hydroxyapatite crystals in the bone matrix, preferentially at the sites of increased bone turnover and inhibit the formation and dissolution of the crystals. Other actions may include direct inhibition of mature osteoclast function, promotion of osteoclast apoptosis, and interference with osteoblast-mediated osteoclast activation. Etidronic acid does not interfere with bone mineralization. In malignancy-related hypercalcemia, etidronic acid decreases serum calcium by inhibiting tumour-induced bone resorption and reducing calcium flow from the resorbing bone into the blood. Etidronic acid also reduces morbidity of osteolytic bone metastases by inhibiting tumour-induced bone resorption. Etidronic acid may promote osteoclast apoptosis by competing with adenosine triphosphate (ATP) in the cellular energy metabolism. The osteoclast initiates apoptosis and dies, leading to an overall decrease in the breakdown of bone."}]