Bisphosphonates are the mainstay in therapeutic option for the prevention and treatment of osteoporosis (1).
- it inhibits osteoclastic activity hence bone resorption (2)
- bisphosphonates include:
- alendronate - the drug of choice for primary and secondary prevention (1)
- cyclic etidronate
- alendronate and etidronate are licensed for the treatment of corticosteroid-induced osteoporosis in men (3).
Bisphosphonates have been shown to increase bone density in post-menopausal women with spinal osteoporosis. Increases of 3% per year have been seen.
A Drug and Therapeutics Bulletin review (3) states:
- on current evidence it seems reasonable to use either alendronate or risedronate as the first-line bisphosphonate for the management of osteoporosis (including corticosteroid-induced osteoporosis), together with calcium and vitamin D supplements if dietary intake is inadequate
- etidronate may be tried for the treatment of vertebral fractures in patients with concomitant oesophageal disease resulting in delayed oesophageal transit or emptying in who alendronate or risedronate are unsuitable
The optimal duration of bisphosphonate therapy has not been established. The continued use of a bisphosphonate should be re-evaluated in individual patients at regular intervals based on the benefits and potential risks, particularly after 5 or more years of use (5)
Time to Benefit of Bisphosphonate Therapy for the Prevention of Fractures Among Postmenopausal Women With Osteoporosis
- analysis (10 RCTs; n=23,384) found that 12.4 months (95% CI 6.3-18.4 months) were needed to avoid 1 non-vertebral fracture per 100 postmenopausal women receiving bisphosphonate therapy, suggesting treatment is likely to benefit those with a life expectancy >12.4 months (6)
- there is evidence relating to the efficacy of using the once-yearly zoledronic acid infusion (7)
- in postmenopausal women with osteoporosis, a once-yearly infusion of 5mg of zoledronic acid during a 3-year period significantly reduced the risk of vertebral, hip, and other fractures
- frequent infusion of intravenous bisphosphonates in patients with cancer is thought to be associated with osteonecrosis of the jaw (2).