Published by Roberto Wenk.
Last updated date: June 6, 2016.
The sodium salt of alendronate, a second generation bisphosphonate and synthetic analog of pyrophosphate with bone anti-resorption activity.
Alendronate sodium binds to and inhibits the activity of geranyltranstransferase (farnesyl pyrophosphate synthetase), an enzyme involved in terpenoid biosynthesis. Inhibition of this enzyme prevents the biosynthesis of isoprenoid lipids (FPP and GGPP) that are donor substrates of farnesylation and geranylgeranylation during the post-translational modification of small GTPase signalling proteins, which is important in the process of osteoclast turnover. As a result, osteoclast activity is inhibited and bone resorption and turnover are reduced.
Used for osteoporosis prevention and treatment, and in management of bone pain or hypercalcemia from metastatic bone cancer.
Dose.
35 - 70 mg orally weekly; with or without Vitamin D: 2800, 5600 IU.
Caution:
• Oral dose to be avoided in those with oesophageal emptying disorders and those who cannot sit upright.
• IV bisphosphonates should be avoided in patients with poor renal function.