Any member of the class of phosphonic acids in which a carbon atom is directly attached to two phosphonic acid groups. They are analogues of pyrophosphates (with the central oxygen atom replaced by a carbon atom) and like pyrophosphates they tend to have a strong affinity for bone, so are frequently used for their antiresorptive and hypocalcaemic properties.
| Member | Definition | Role |
|---|
| 6-amino-1-hydroxyhexane-1,1-diphosphonate | | neridronic acid |
| alendronate | A 1,1-bis(phosphonic acid) that is methanebis(phosphonic acid) in which the two methylene hydrogens are replaced by hydroxy and 3-aminopropyl groups. | alendronic acid |
| clodronic acid | An organochlorine compound that is methylene chloride in which both hydrogens are replaced by phosphonic acid groups. It inhibits bone resorption and soft tissue calcification, and is used (often as the disodium salt tetrahydrate) as an adjunct in the treatment of severe hypercalcaemia associated with malignancy, and in the management of osteolytic lesions and bone pain associated with skeletal metastases. | clodronic acid |
| etidronate | A 1,1-bis(phosphonic acid) that is (ethane-1,1-diyl)bis(phosphonic acid) having a hydroxy substituent at the 1-position. It inhibits the formation, growth, and dissolution of hydroxyapatite crystals by chemisorption to calcium phosphate surfaces. | etidronic acid |
| hydroxymethanediphosphonic acid | | oxidronic acid |
| incadronate | | incadronic acid |
| l 690330 | | [1-(4-hydroxyphenoxy)-1-phosphonoethyl]phosphonic acid |
| methylene diphosphonate | A 1,1-bis(phosphonic acid) consisting of methane substituted by two phosphonic acid groups. | medronic acid |
| risedronate sodium | | Risedronate sodium |
| zoledronic acid | An imidazole compound having a 2,2-bis(phosphono)-2-hydroxyethane-1-yl substituent at the 1-position. | zoledronic acid |