Higher persistency rates were seen among osteoporosis patients taking Fosamax Once Weekly (alendronate) therapies than were seen among patients taking ibandronate once monthly or once weekly risedronate therapies, according to results from two new outcomes studies conducted by Merck & Co., Inc. that compared persistency rates of weekly versus monthly oral bisphosphonate dosing frequency.

Both studies were based on a review of two prescription drug databases containing prescription records from a total of over 300,000 patients in the US. These data were presented at the 28th Annual Meeting of the American Society for Bone Mineral Research (ASBMR).

"The results from both studies are noteworthy because they suggest that persistency rates are not higher with monthly dosing of oral bisphosphonates versus weekly dosing," said Thomas W. Weiss, Dr PH, senior manager, Outcomes Research, Merck & Co., Inc. and lead study author. "Another recent study showed patients placed a higher importance on a drug's proven ability to reduce the risk of bones breaking versus other attributes of osteoporosis therapy - including dosing frequency." (Current Medical Research and Opinion, May, 2006).

Monthly versus weekly persistency study. This first study evaluated whether monthly dosing of oral bisphosphonates improved treatment persistency compared to weekly dosing.

The study included 272,232 women aged 50 or older who had filled a new prescription for weekly alendronate or alendronate cholecalciferol, weekly risedronate or risedronate with calcium. Actonel or Actonel with Calcium; or monthly ibandronate from April 2005 to July 2005 and who had no prescriptions for the newly prescribed bisphosphonate during the 12 months prior to the date of their initial prescription fill. All patients were followed for 365 days after the date of the initial prescription fill.

Fosamax is the only bisphosphonate that is indicated to significantly reduce the risk of both osteoporotic hip and spine fractures. The sustained efficacy of Fosamax for the treatment of osteoporosis in postmenopausal women was demonstrated in a trial that found in over 10 years of therapy Fosamax 10 mg once daily maintained or continued to help build bone.

Osteoporosis can lead to bone loss and an increased risk of fractures. Osteoporosis is especially common in women after menopause, but also occurs in men. Most often, it is due to an increase in the rate of resorption of bone tissue that is not matched by the rate of bone formation.