Millions of postmenopausal women are taking a bisphosphonate like oral alendronate (Fosamax) or intravenous (IV) zoledronic acid (Reclast) to increase bone density. But because long-term use of these drugs has been associated with an increased risk of bone death in the jaw and unusual thighbone fractures, experts have debated how long women should stay on the drugs to minimize the risk of hip or vertebral fractures without raising their risk for these rare but serious complications.

After considering major randomized controlled clinical trials, a task force of the American Society for Bone and Mineral Research has released guidelines on the optimal duration of bisphosphonate therapy for osteoporosis. The guidelines, published in the January 2016 issue of the Journal of Bone and Mineral Research, recommend reassessing a woman's fracture risk after five years of oral bisphosphonates or three years of IV therapy. They advise that women whose risk is still high should continue to take oral bisphosphonates for up to 10 years or IV therapy for up to six years. However, fracture risk should be reassessed every two to three years during extended therapy.

For women determined to be at low risk after five years of oral therapy or three years of IV therapy, treatment may be discontinued, but fracture risk should be reassessed periodically.

Guidelines are only advice, not mandates. If you are at high risk for a fracture of the hip or spine, the decision to take—or to continue taking—a bisphosphonate is one to make with your doctor after considering your general health, the potential risks and benefits of the medication, and your preferences.