"Nothing is more important to Merck than the safety of its medicines," according to a written statement by Merck to ABC News. A causal relationship between Fosamax and these fractures has not been established, according to Merck.
"The drug companies have to recognize when there is a problem, they have to be up front with the public. If there's a concern, they have to voice it and at least give everybody a fair chance to look at this carefully," said Dr. Joseph Lane, orthopedic trauma surgeon at the Hospital for Special Surgery in New York City.
Many studies suggest an overall benefit from taking the medication for women who are at risk for osteoperosis. In fact, bisphosphonates can help prevent hip and spine fractures, which for many women may lead to death.
"Normally your bone is constantly being remade," said Dr. Joseph Lane, chief of metabolic bone disease at the Hospital for Special Surgery in New York City. "These patients don't remake their bone and they acquire damage, microdamage, the collagen gets altered and we need to rejuvenate the skeleton."
In 2008, bisphosphonate sales exceeded $3.5 billion according to data from IMS Health. In 2008, over 37 million prescriptions were written for the osteoporosis medications.
While some physicians use bone density scans to help drive their decisions, doctors generally prescribe them to women who are at an increased risk for either osteoporosis or fractures from osteoporosis they already have. A new tool developed by the World Health Organization can determine the risk of having fractures and can help doctors determine which women with osteoporosis should be treated with medications.
Although bisphosphonates are generally recommended for postmenopausal women, research does not indicate how long women should be on the drug. Many doctors now recommend a five-year limit.
"When they are on it for five, six, seven or eight years, they lost their ability to remodel and regenerate their skeleton," said Lane. "[Some women] are very vulnerable and they will then develop problems of brittle bone."
Additional time on the medication depends on doctors' orders, said Besser.