0915 Once-per-year bisphosphonate for glucocorticoid-induced osteoporosis

While osteoporosis is generally (and correctly) considered to be a condition affecting peri- and post-menopausal women, any doctor treating chronic patients with long-term glucocorticoids should remember that his patient/s will be at risk for the disease. Glucocorticoids decrease bone formation by reducing the lifespan of osteoblasts and osteocytes. This is a different process from that seen in post-menopausal osteoporosis where the problem is one of augmented bone resorption, a difference that might argue for treatment with other drugs such as strontium or teriparatide (which acts on osteocytes and osteoblasts). Notwithstanding the latter argument, calcium, vitamin D and bisphosphonates have been accepted as appropriate treatment for glucocorticoid-induced osteoporosis in adults (treatment as well as prevention) using daily or weekly regimens of alendronate or risedronate to reduce bone resorption through their action on osteoclasts. However patient adherence/compliance tends to be low, so researchers have turned their attention to preparations that could be administered at greater intervals. One such study, recently published in the Lancet, involved 800+ adult subjects from 54 centres in Europe, Australia, Hong Kong, Israel and the USA. One intravenous dose of zoledronic acid was tested against daily oral risedronate and patients were followed for one year. Randomisation was carried out, allocating patients to control vs study groups and treatment vs prevention groups (based on prior duration of glucocorticoid treatment). Apart from a greater incidence of flu-like symptoms shortly after the administration of zoledronic acid the drug proved to be superior in terms of lumbar, femoral and hip bone density. The study was not powered to detect differences in fracture rates, and in fact there is not a perfect relationship between bone density and turnover and fracture rate, but for now it would appear that once-per-year zoledronic acid would compare more than favourably with previous bisphosphonate regimens.

Read more:
Lancet 2009; 373: 1225-6 and 1253-63
Osteoporos Int 2007; 18: 1319-28
J Biol Chem 2005; 280: 7317-25