Bisphosphonate therapy is generally limited to how many years due to risk of subtrochanteric fractures?

• A. 5 years
• B. 2 years
• C. 10 years
• D. 1 year

Answer: (A)

Long-term suppression of bone turnover from bisphosphonates can reduce fracture risk, but after several years the remodeling suppression may lead to accumulation of microdamage and atypical fractures in the subtrochanteric region. Because of this balance between benefits and a rare but serious risk, therapy is generally limited to about five years before re-evaluating the need for continued treatment. If fracture risk remains high, a careful drug holiday or alternative strategy may be considered; otherwise continuing beyond this period increases the chance of subtrochanteric fractures, even though the overall risk remains low.

One year is typically too short to justify a limit, and ten years is longer than commonly recommended because the risk of these atypical fractures rises with prolonged use. Two years is also shorter than the standard practice of revisiting after about five years.