Atypical femur fracture during bisphosphonate drug holiday: a case series.

Recent studies have noted an increased risk of low energy subtrochanteric and femoral shaft fractures termed "atypical femur fractures" (AFFs) associated with long-term bisphosphonate use. As such, many clinicians have begun recommending a "drug holiday" to reduce the risks associated with long-term bisphosphonate use. We present two cases of AFFs occurring during a 4-year or greater drug holiday following long-term bisphosphonate use. These findings highlight the need to reevaluate optimal bisphosphonate therapy duration, dosage, as well as initiation and duration of a drug holiday with continued monitoring in the prevention of AFFs.