Intermittent regimen with new bisphosphonate cuts fractures. (Ibandronate in 3-Month Cycle).

SAN ANTONIO -- For the first time, an intermittent bisphosphonate regimen has been shown to cut the incidence of osteoporotic fractures in postmenopausal women.

Treatment with ibandronate--a new bisphosphonate under marketing review by the Foodand Drug Administration for treating osteoporosis with a daily dosing regimen-- reduced the fracture rate in a controlled 3year study that included almost 3,000 women. With the intermittent regimen, women took the drug every other day for 24 days, followed by a treatment hiatus of about 66 days before repeating the cycle, Dr. Robert R. Recker reported at the annual meeting of the American Society for Bone and Mineral Research.

"This is the first real demonstration of the efficacy of an intermittent regimen with a bisphosphonate," commented Dr. Socrates E. Papapoulos, professor of endocrinology at Leiden (the Netherlands) University.

Last February an international team of researchers reported that an intravenous dose of the bisphosphonate zoledronic acid, given once every 3 months, led to improved bone mineral density (N. Engl. J. Med. 346[9]:653-61, 2002). The new report is the first to test the effect of intermittent dosing on fracture rates.

But the awkward ibandronate regimen used in the new study is unlikely to be readily adopted in clinical practice. "The dosing schedule is too complicated and impractical. An intermittent regimen makes sense, but not one where patients always need to check a calendar," said Dr. Michael McClung, director of the Oregon Osteoporosis Center, Portland.