In pharmacology, bisphosphonates (also called diphosphonates) are a class of drugs that prevent the loss of bone mass, used to treat osteoporosis and similar diseases.
Bone has constant turnover, and is kept in balance (homeostasis) by osteoblasts creating bone and osteoclasts digesting bone. Bisphosphonates inhibit the digestion of bone by osteoclasts.
Osteoclasts also have constant turnover and normally destroy themselves by apoptosis, a form of cell suicide. Bisphosphonates encourage osteoclasts to undergo apoptosis.
The uses of bisphosphonates include the prevention and treatment of osteoporosis, osteitis deformans ("Paget's disease of bone"), bone metastasis (with or without hypercalcaemia), multiple myeloma, primary hyperparathyroidism, osteogenesis imperfecta and other conditions that feature bone fragility.
Bisphosphonates were developed in the 19th century but were first
investigated in the 1960s for use in disorders of bone metabolism.
non-medical use was to soften water in irrigation systems used in
orange groves. The initial rationale for their use in humans was their
potential in preventing the dissolution of hydroxylapatite, the
principal bone mineral, thus arresting bone loss.
Only in the 1990s was
their actual mechanism of action demonstrated with the initial launch of
Fosamax (alendronate) by Merck.
All bisphosphonate drugs share a common P-C-P "backbone":
The two PO3 (phosphonate) groups
covalently linked to carbon determine both the name "bis''phospho''nate"
and the function of the drugs.
The long ''side-chain'' determines the chemical properties, the mode of action
and the strength of bisphosphonate drugs. The short ''side-chain', often called the 'hook', mainly influences chemical
properties and pharmacokinetics.
This article is licensed under the Creative Commons Attribution-ShareAlike License.
It uses material from the Wikipedia article on
All material adapted used from Wikipedia is available under the terms of the
Creative Commons Attribution-ShareAlike License.
Wikipedia® itself is a registered trademark of the Wikimedia Foundation, Inc.