An osteoporosis drug delivered once a year has been shown to be as effective as current monthly or weekly osteoporosis regimens at reducing the incidence of bone fractures. Zoledronic acid (marketed as Reclast), is an investigational drug in the bisphosphonate drug category, being developed by Novartis Pharmaceuticals Corp., and is still in the approval process through the Food and Drug Administration.

Impact included a 70 percent reduction in the risk of spinal fractures and a 40 percent reduction in the risk of hip fractures. The effect was sustained over three years.

"The reductions in hip and spine fractures were at least as large as those seen with other drugs in this category," said Dennis Black, PhD, a professor of epidemiology and biostatistics in the UCSF School of Medicine, who led the study. "But even more remarkable were the strong, significant and consistent effects across all fracture types."

Aside from its efficacy and convenience, the study also indicated that, at doses required for osteoporosis treatments, side effects such as renal damage and bone deterioration were not observed, although there was a small increase in the incidence of atrial fibrillation among the patients who received the drug.

As an aside, May is the National Osteoporosis Awareness and Prevention Month in the US.