Alendronate and risedronate for the treatment of postmenopausal osteoporosis: clinical profiles of the once-weekly and once-daily dosing formulations.

OBJECTIVE: The objective of this review is to present the clinical profiles of the once-weekly and once-daily dosing formulations of alendronate and risedronate, the 2 bisphosphonates currently available in the United States for the prevention and treatment of postmenopausal osteoporosis. DATA SOURCE/STUDY SELECTION: Data were obtained from a MEDLINE literature search of all English language articles published between January 1996 and April 2004 using generic names of the bisphosphonates alendronate and risedronate. Results were refined by incorporating terms such as "osteoporosis," "bone mineral density," "fracture risk," and "adverse events." Randomized, controlled trials of once-daily and once-weekly bisphosphonate therapies were selected. Also selected for review were post hoc analyses and extension studies of the original controlled trials, including more recent data from published abstracts from scientific meetings. DATA EXTRACTION: Relevant portions of articles obtained from the literature search were used to summarize the efficacy and tolerability of the 2 therapies. CONCLUSIONS: In prospective trials, both bisphosphonates were effective in reducing vertebral and hip fractures in women with postmenopausal osteoporosis. In the only prospective trial evaluating hip fracture risk reduction as the primary end point, risedronate was effective at reducing hip fracture vs placebo. Both alendronate and risedronate are available in once-weekly formulations that have efficacy and tolerability profiles similar to the once-daily doses. Clinicians should review all available data for both agents as well as the medical history of the patient to make the most appropriate treatment choice.