A once-a-year injection of a common osteoporosis drug may provide an easy way to protect women against the risk for bone fractures—and might even replace bone-building pills, say researchers. The findings could open the door to the US Food and Drug Administration's approval of once-a-year zoledronic acid.

"Here we've got something we can give to patients when they're in the clinic with a 15-minute IV, and it lasts for a whole year," says Paul Brandt, an assistant professor of neuroscience and experimental therapeutics at Texas A&M Health Science Center College of Medicine in College Station.

Brandt was not involved in a new study that shows great promise in this quarter-hour treatment. "The FDA hasn't approved it for a single-year injection, but I hope it will. It sure is going to be a good kick in the right direction."

The Study

The research examined the efficacy of annual injections over three years.

Almost 4,000 postmenopausal women were randomly assigned to receive either a single 15minute infusion of zoledronic acid, or a placebo, at the study's start, and then again 12 months and 24 months later. Participants were followed out to the three-year point.

Those treated with zoledronic acid injections had a 70% lower risk of vertebral fractures and were 41% less likely to suffer hip fractures.

They also experienced significant improvement in bone mineral density and bone metabolism markers.

The downside to the injections: They have a higher incidence of an irregular heart rhythm called atrial fibrillation. Other side effects were similar in both groups, say researchers.

A Better Option?

Experts say these results are encouraging—especially when they consider that many women in the study were already take bone-preserving pills called oral bisphosphonates.

These pills are not for everyone, says Dr. Nanette Santoro, director of the division of reproductive endocrinology in the department of obstetrics and gynecology and women's health at Montefiore Medical Center in New York City.

"For now, women who do not tolerate oral bisphosphonates well but who are good candidates will be able to take the medication in a relatively convenient form," she says.

The pills work by slowing the body's natural resorption of bone. But one common problem with bisphosphonates is that patients don't take the drugs as they should.

"The big concern has been in patient compliance," says Brandt. “The monthly pills run into problems where women start to forget. It's also a pain to take these drugs. You have to sit upright and there's a risk of acid reflux, esophageal damage."

Women also have to take the pills with a full glass of water while fasting.

Another expert, Dr. Steven R. Goldstein, a professor of obstetrics and gynecology at New York University School of Medicine and author of The Estrogen Alternative and Could It Be Menopause..., believes the new study to be a very nice alternative."

He calls the injection "an attractive alternative for a significant number of people who cannot or will not take traditional antiresorptive medication."

Women, Watch Your Knees!

Women have wider hips than men, which puts more stress on the knees, according to a new report. Women also have more estrogen, which makes ligaments flexible but also reduces their ability to absorb shocks.

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