| Stereochemistry | ACHIRAL |
| Molecular Formula | C2H8O7P2 |
| Molecular Weight | 206.0282 |
| Optical Activity | NONE |
| Defined Stereocenters | 0 / 0 |
| E/Z Centers | 0 |
| Charge | 0 |
SHOW SMILES / InChI
SMILES
CC(O)(P(O)(O)=O)P(O)(O)=O
InChI
InChIKey=DBVJJBKOTRCVKF-UHFFFAOYSA-N
InChI=1S/C2H8O7P2/c1-2(3,10(4,5)6)11(7,8)9/h3H,1H3,(H2,4,5,6)(H2,7,8,9)
| Molecular Formula | C2H8O7P2 |
| Molecular Weight | 206.0282 |
| Charge | 0 |
| Count |
MOL RATIO
1 MOL RATIO (average) |
| Stereochemistry | ACHIRAL |
| Additional Stereochemistry | No |
| Defined Stereocenters | 0 / 0 |
| E/Z Centers | 0 |
| Optical Activity | NONE |
Etidronate is a salt of etidronic acid (brand name Didronel, also known as EHDP) a diphosphonate, which is indicated for the treatment of symptomatic Paget’s disease of bone and in the prevention and treatment of heterotopic ossification following total hip replacement or due to spinal cord injury. Didronel is not approved for the treatment of osteoporosis. This drugs acts primarily on bone. It can inhibit the formation, growth, and dissolution of hydroxyapatite crystals and their amorphous precursors by chemisorption to calcium phosphate surfaces. Inhibition of crystal resorption occurs at lower doses than are required to inhibit crystal growth. Both effects increase as the dose increases. Preclinical studies indicate etidronate disodium does not cross the blood-brain barrier. Didronel is not metabolized. The amount of drug absorbed after an oral dose is approximately 3 percent. 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 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.
CNS Activity
Approval Year
PubMed
Patents
Sample Use Guides
should be taken as a single, oral dose. Paget’s Disease: Initial Treatment Regimens: 5 to 10 mg/kg/day, not to exceed 6 months, or 11 to 20 mg/kg/day, not to exceed 3 months. The recommended initial dose is 5 mg/kg/day for a period not to exceed 6 months. Doses above 10 mg/kg/day should be reserved for when 1) lower doses are ineffective or 2) there is an overriding need to suppress rapid bone turnover (especially when irreversible neurologic damage is possible) or reduce elevated cardiac output. Doses in excess of 20 mg/kg/day are not recommended.
Route of Administration:
Oral
In vitro cytotoxicity of etidronic acid to MCF-7 cells was estimated on the basis of clonogenicity assays, while cell cycle effects were determined by using flow cytometry. A 24-hour treatment with etidronic acid (10 mM) with or without strontium chloride was cytototoxic to MCF-7cells. Etidronic acid (1, 10 mM) caused a decrease in the S-phase population and an increase in the G2/M population. Treatment of MCF-7 human breast cancer cells with etidronic acid (10 mM) for six hours caused mutations in exons 6 and 8 of the p53 gene in MCF-7 cells.
