Fosamax Remains Safe and Effective Long-Term
Osteoporosis Drug Still Beneficial After a Decade of Use
WebMD News Archive
March 17, 2004 - There is good news about the drugs used to treat and prevent osteoporosis-related bone loss. The longest-ever study of one of the most widely prescribed of these drugs suggests it continues to protect bones after a decade of use.
The study showed that the drug Fosamax was effective in maintaining bone mineral density at the spine for 10 years, regardless of the age of the patients or the extent of bone loss at the start of treatment.
Millions of postmenopausal women in the U.S. have taken Fosamax since it was first approved in 1995, and the findings should reassure those who are approaching the end of their first decade on the drug.
"The two main questions that people might have about the long-term effects of this drug and the others are, 'Do they work?' and 'Is there any harm in long-term treatment?'" the study's aptly named lead researcher, Henry G. Bone, MD, tells WebMD. "Our findings 10 years out suggest that this drug continues to work with no indication of any negative impact related to its long-term use."
Benefits Continued After Treatment Stopped
Postmenopausal women taking 10 mg of Fosamax daily for 10 years had an average increase in bone mineral density at the spine of 13%. And bone density remained stable at other bone sites measured during the study.
A second group of women who took Fosamax for the first five years of the trial, but then discontinued the drug, saw gradual declines in bone density during a five-year period after discontinuing therapy, but therapeutic benefits remained throughout the follow-up period.
The findings are published in the March 18 issue of The New England Journal of Medicine.
Fosamax and most other drugs used to prevent bone loss work by slowing the natural breakdown of bone. In doing so, the mineral content of bones may overly increase, a process known as mineralization. There has been some concern that too much mineralization could cause bones to become more brittle and susceptible to fractures. The latest findings showed little evidence of this, but the study's small size prevented the authors from studying fractures.
Osteoporosis treatment expert Gordon J. Strewler, MD, of Harvard Medical School, says there are still unanswered questions about the long-term benefits of osteoporosis treatments like Fosamax. In an editorial accompanying the study, Strewler writes that clinicians need "better data regarding the relative risk of fracture associated with continued treatment as compared with the discontinuation of treatment."
"Although 10 years of [Fosamax] treatment appears to be safe, the optimal duration of treatment has not been established," he notes. "Is there an eventual point at which the benefit of treatment with regard to protection of fractures will diminish? ... Could treatment be stopped after 10 or more years with persistent protection against fractures?"