FDA Warns to Limit Use of Fosamax, Other Bisphosphonate Drugs

June 27, 2012 — The FDA has published a consumer update advising patients to limit their use of bisphosphonate drugs for osteoporosis (including Fosamax, Boniva, and more) to 3-5 years. An FDA review of clinical studies found that patients could stop using the drugs after 3-5 years and may still receive the long-term benefits. An FDA study that made this conclusion was published in the New England Journal of Medicine on May 31, 2012.

More than 44 million Americans are at risk of osteoporosis, which is a condition in which the bones gradually become weaker and are more likely to break. The bisphosphonate class of drugs have been widely used for almost two decades to help restore bone loss. The most popular drugs in this class include Fosamax, Boniva, Actonel, Aredia, and Atelvia, as well as several generic drugs.

According to the FDA, further studies are necessary to better understand the long-term risks and benefits of using these drugs. According to an FDA medical officer, “We just don’t know yet the optimum period of time individuals should be on the drug to both maximize its effectiveness and minimize potential risks.” Further research could help the FDA better understand the risk of bone fractures in patients who stop taking a bisphosphonate, and whether re-starting the drug later in life is beneficial.

Bisphosphonates have been linked to several serious side effects. One is osteonecrosis of the jaw, which involves severe decay of the jaw bone. Another potential side effect is the risk of unusual femur fractures. The drugs have carried warnings for these side effects since 2010.

While many studies have shown that bisphosphonates are very effective at protecting against bone fractures, the studies showing these results have only been conducted for 3-5 years. Although many people take these drugs for longer than 3-5 years, experts do not know the long-term safety or effectiveness of these drugs.

It is possible that a few years of treatment could have long-term benefits, even when the drug is discontinued. This is because, over time, the drug is incorporated into the bones. The bones are constantly undergoing a process of formation and disintegration. Osteoporosis occurs when bones disintegrate faster than they form — bisphosphonates slow down disintegration, which helps stop bone loss. Bisphosphonate drugs are incorporated into the bones, and they can remain there for several years after the drug is stopped, potentially providing long-term bone protection. However, experts do not know how long benefits actually last.

The FDA recommends that patients who are currently taking a bisphosphonate osteoporosis drug should talk to their doctor about whether to continue taking the drug. Furthermore, patients should periodically re-evaluate the risks and benefits of the drug therapy.