Once-yearly zoledronic acid reduces fracture risk
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Osteoporosis: bone density can be improved with zoledronic acid |
A once-yearly infusion of zoledronic acid reduces the risk of vertebral, hip and other fractures in postmenopausal women, according to new research.
The finding supports earlier work showing zoledronic acid decreases
bone turnover and improves bone density for at least 12 months after
infusion, and suggests that the drug could be a useful treatment option
where adherence to oral medication for osteoporosis is a problem.
Researchers assigned 7,765 women to receive a single 15-minute infusion
of zoledronic acid or placebo at baseline, at 12 months and at 24 months.
After three years, 310 women (10.9 per cent) in the placebo group had
experienced a vertebral fracture compared with 92 women (3.3 per cent)
in the zoledronic acid group (relative risk 0.30, 95 per cent confidence
interval 0.24 to 0.38). Similar reductions in risk were seen after one
and two years.
The incidence of hip fracture was also reduced (2.5 per cent for women
given placebo compared with 1.4 per cent for women treated with zoledronic
acid), as were all other prospectively defined categories of fracture,
including non-vertebral fractures and clinical vertebral fractures (P<0.001
for all comparisons).
“Given the relatively poor adherence to oral bisphosphonate therapy
in clinical practice, annual infusion of zoledronic acid may provide
a promising
approach to reducing fracture risk,” the researchers conclude.
The study, supported by Novartis, is published in The New England
Journal of Medicine (2007;356:1809).
The author of an accompanying editorial (ibid, p1878)
describes the data as impressive and says that the absence of long-term
adverse effects
on renal function is reassuring, as is the lack of evidence linking zoledronic
acid with osteonecrosis of the jaw. However, she highlights the increase
in atrial fibrillation seen in women treated with zoledronic acid as
an unexpected adverse effect. “A causal relationship must be given
serious consideration,” she writes.
Zoledronic acid is not currently licensed in the UK for the treatment
of osteoporosis. |
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