Fosamax, generic name alendronate, is a drug in the bisphosphonate class of medications, which help strengthen bone. Bisphosphonates, such as Fosamax, are used to treat osteoporosis. They are also used to help relieve bone pain from metastatic cancers that invade the bones. However, there has been mounting evidence that this drug and others in its class may cause serious side effects if used longer than five years. Those taking bone-strengthening drugs, should understand the possible dangers of long-term use.
Esophageal Cancer
Fosamax can cause gastrointestinal side effects. In fact, patients who take Fosamax are instructed to avoid lying down after taking this medication, to prevent acid reflux. Common side effects of bisphosphonates include heartburn, throat irritation, and even difficulty swallowing. Erosion of the upper intestinal tract can increase the risk of gastrointestinal bleeding. Recently, however, a much more serious gastrointestinal risk has come to light. According to a study published in the September 2010 issue of "British Medical Journal," the use of bisphosphonates such as Fosamax over a period of three or more years was linked to a doubling of the risk for esophageal cancer. No increased risks were found for colon or gastric cancer. Although the risk for esophageal cancer is doubled, the overall risk is still low. Even so, doctors and patients must be aware of this risk and evaluate upper intestinal symptoms promptly.
Osteonecrosis of Jaw
Osteonecrosis is a process that involves death of bone tissue. In the case of osteonecrosis of the jaw, or ONJ, bone death results from infection and failure to heal after minor procedures such as tooth extraction. According to 2010 information from the U.S. Food and Drug Administration, a study they sponsored found that the rate of ONJ in patients who were using Fosamax was 1 in 900. Most of the patients who developed ONJ were cancer patients. Many of the patients also took chemotherapy or steroids in addition to the Fosamax. It is not proven that Fosamax is a cause of ONJ, but it is probably a good idea to discontinue bisphosphonates prior to dental work, or to delay starting the medication until dental work is completed. The FDA evidence suggests that the ONJ risk is primarily increased in cancer patients, not osteoporosis patients.
Femur Fracture
Bisphosphonates are designed to strengthen bone. However, there is a concern that long-term use might actually weaken bones. According to a May 20101 article in the "Journal of the American Medical Association," there is some evidence that long-term bisphosphonate use may be linked to an unusual type of femoral fracture. The femur is the main long bone in the leg. Several cases of a severe femoral break that occurred with only minimal trauma occurred in patients who had been taking Fosamax for several years. In March of 2010, the FDA recommended a labeling change to inform patients of the possible risk of femur fracture.
Fosamax Effects
Bisphosphonates work by inhibiting osteoclasts, a type of cell that breaks down bone tissue. Osteoclasts are important in bone remodeling, a natural process in the growth and maintenance of normal bone. Inhibition of these cells results in increased bone density. When bones are denser, they are stronger. According to MayoClinic.com, Fosamax has been proven to reduce the risk of bone fracture for up to 3 to 5 years.
Long-Term Use
The effectiveness of Fosamax in the short term is well known; the long-term safety of Fosamax is not certain. However, according to Dr. Kurt Kennel of MayoClinic.com, it may be reasonable to stop taking Fosamax after five years of treatment. The medication seems to build up in the bone, and it may have a positive effect after discontinuation. The decision about whether or not to take Fosamax is a very personal decision. Whatever choice is made, a physician should monitor bone density and potential drug side effects in any patient with osteoporosis.
References
- "British Medical Journal"; Oral bisphosphonates and oesophageal cancer; Diane K Wysowski; September 2010
- Food and Drug Administration
- "Journal of the American Medical Association"; Studies Probe Possible Link Between Bisphosphonates and Femoral Fractures; Bridget M. Kuehn; May 2010
- Mayo Clinic: Osteoporosis
