The Food and Drug Administration estimates that over 10 million Americans are affected by osteoporosis, a condition which involves progressive weakening of the bones and can result in easy injury, particularly in the elderly. Women are at a particular risk of developing the disease. A class of bone drugs called bisphosphonates have been widely prescribed to slow the loss of bone mass, with more than 150 million prescriptions issued between 2005 and 2009 to help promote bone growth and reduce the risk of fractures.
And new data from the FDA suggest that these drugs, known by the brand names Fosamax, Boniva, and Reclast, may be doing more harm than good with long-term use. In rare cases, using the drugs for more than 3-5 years can result in serious adverse events, including unusual femur fractures, esophageal cancer, and osteonecrosis of the jaw – a condition which causes painful, disfiguring crumbling of bone.
These kinds of serious complications are worrying but rare. Unfortunately, no is sure exactly how rare – estimates for the rate of bisphosphonate-related fractures range from 1 in 10,000 users to 10 in 10,000. Some are calling for more research to be done on whether the drugs are safe - and wondering why a drug with such dangerous potential side effects was given such quick approval.
The more important implication of the study is the finding that most patients don’t benefit from long-term use of these drugs either way. In wake of this news, experts consulted by the New York Times predict that many doctors will probably stop prescribing bone drugs to their patients, resulting in anywhere from 60-70% of those currently taking the drugs going off them.
Unfortunately, the FDA hasn’t issued any specific guidelines for safe long-term use yet. Some patients with osteoporosis may continue to benefit from use of bisphosphonates long-term, and the risks versus benefits need determined on a case-by-case basis.
Photo credit: Asja Boros