The action of ibandronate on bone tissue is based partly on its affinity for hydroxyapatite, which is part of the mineral matrix of bone. Nitrogen-containing bisphosphonates (such as pamidronate, alendronate, risedronate, ibandronate and zoledronate) appear to act as analogues of isoprenoid diphosphate lipids, thereby inhibiting farnesyl pyrophosphate (FPP) synthase, an enzyme in the mevalonate pathway of cholesterol biosynthesis. Inhibition of this enzyme in osteoclasts prevents the biosynthesis of isoprenoid lipids (FPP and GGPP) that are essential for the post-translational farnesylation and geranylgeranylation of small GTPase signaling proteins. This activity inhibits osteoclast activity and reduces bone resorption and turnover. In postmenopausal women, it reduces the elevated rate of bone turnover, leading to, on average, a net gain in bone mass.
Seibel, M.J. Bone metabolism. In S. Offermanns, & W. Rosenthal (Eds.). Encyclopedic reference of molecular pharmacology. 2004;190-197. Berlin, Germany: Springer.
Steroid Biosynthesis References
Lehninger, A.L. Lehninger principles of biochemistry (4th ed.) (2005). New York: W.H Freeman.
Norman, A.W, and Litwack, G. Hormones (2nd ed.) (1997) San Diego : Academic Press.
Salway, J.G. Metabolism at a glance (3rd ed.) (2004). Alden, Mass.: Blackwell Pub.
Vance, D.E., and Vance, J.E. Biochemistry of lipids, lipoproteins, and membranes (4th ed.) (2002) Amsterdam; Boston: Elsevier.
Simons J: The $10 billion pill. Fortune. 2003 Jan 20;147(1):58-62, 66, 68.
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