Bisphoshonate Benefits Plateau at Five Years, FDA SaysSep 8, 2011 | Parker Waichman LLP
Women who take oral bisphosphonates such as Fosamax to prevent broken bones from osteoporosis may not have to take them beyond five years to get their full benefit, a new U.S. Food & Drug Administration (FDA) staff report says. This is good news, considering some of the serious side effects that have recently been linked with long-term use of bisphosphonates, including a rare type of thigh fractures.
The FDA staff report was released ahead of an advisory panel meeting that will take a look at the long-term safety of bisphosphonates like Fosamax. Most studies involving the drugs have only looked at a few years of data. Tomorrow, the FDA will ask two of its advisory panels to recommend whether the women who take bisphosphonates to treat osteoporosis should take a "drug holiday" - a temporary break - from the medications, or if use should be restricted to just a few years.
According to the FDA staff report, there is evidence to link long-term use of bisphosphonates to problems like atypical thigh fractures, as well as osteonecrosis of the jaw. However, current studies have not established causation. “The safety of long-term bisphosphonate therapy continues to be unclear as study results are conflicting,” the newly-released FDA report says.
The report also raises questions about the drugs' long-term effectiveness, finding that women who stop taking the drugs after five years experienced similar benefits to those who continued taking them. While no benefit was seen in women who took the drugs for less than three years, fewer broken bones from osteoporosis were seen in women who used them between three and five years.
The report is non-committal on the question of a drug holiday, stating that while such a strategy might be warranted, there is "no substantial data available to inform decisions regarding the initiation or duration of a drug holiday.”