Fosamax, one in a class of drugs known as bisphosphonates, is supposed to make bones stronger. But new research suggests staying on the drug for five or more years can increase the risk of hip fractures.
Two new studies show the bones of post-menopausal women who take bisphosphonates (Actonel, Boniva, Fosamax, Reclast) to treat osteoporosis can stop rejuvenating and become brittle after long-term use. Researchers urge limiting the length of time people take the drugs.
One study found, 111 postmenopausal women with osteoporosis, who had been taking bisphosphonates for four or more years had a raised risk for an unusual type of femur fracture. The findings were compared with 50 women who were taking calcium and vitamin D supplements but not bisphosphonates for bone health.
Researchers stress that these drugs are still useful in the early years of use and people should not stop using them. However, more research is needed, says Dr. Melvin Rosenwasser of chief of orthopedic trauma surgery at Columbia University Medical Center.
“These are good drugs. They strengthen bone and protect from fractures for a while,” says Dr. Rosenwasser. “But, in some people they can become harmful after a period of time.”
Findings from both studies were presented at the American Academy of Orthopaedic Surgeons' annual meeting in New Orleans.
An estimated 10 million Americans, mostly women, have osteoporosis.
Osteoporosis happens when the bone building process within our body reverses itself after the age of 35. Then we breakdown more bone than we build leading to overall decline in bone mass. The quality and quantity of bone in adults is established by diet and exercise by the age of 18 in girls and 20 in boys.
Bisphosphonates are a class of drugs that slow or stop reabsorption of bone. They can reduce the risk of bone fracture, and in some cases can increase bone mass in those with osteoporosis. In cancer patients, they slow bone turnover in people with cancer of the bones or multiple myeloma.
Fosamax and similar drugs have been linked to other medical conditions in the past including heart irregularity, osteonecrosis of the jaw and most recently esophageal Cancer.