Osteoporosis Experts Discuss Bisphosphonate Holidays

According to one post-hoc analysis of this trial’s data, women whose hip T-scores remained low seem to benefit from continuing alendronate.⁵ Another post-hoc analysis looked at the 437 women in the placebo group and found their new fractures were not predicted by three important markers of declining bone: one-year changes in hip bone density, one-year changes in the bone resorption marker N-telopeptide or one-year changes in bone-specific alkaline phosphatase. They were at higher risk for new fractures if their femoral neck T-score was -2.5 or lower when they stopped alendronate or if they had a 3% or greater decline in total hip bone mineral density over two years.⁶

Guideline Update

In 2016, the American Society for Bone and Mineral Research (ASBMR) updated its guideline on bisphosphonate holidays. In post-menopausal women treated with oral bisphosphonates for five or more years or intravenous therapy for three or more years, it recommends:

• If the patient has had a hip, spine or multiple other osteoporotic fractures before or during bisphosphonate therapy, consider continuing the current bisphosphonate or changing to an alternative drug, then reassess every two to three years.
• If the patient has not had one of these fractures before or during therapy, consider if their hip bone mineral density T-score is 2.5 or lower or if they are at a high fracture risk.
• If so, consider continuing bisphosphonates for up to 10 more years or changing to an alternative drug, then reassess every two to three years.
• If not, consider a drug holiday and reassess every two to three years.

According to the guideline, high fracture risk factors include being age 70 or older and a Fracture Risk Assessment Tool (FRAX) score above their country-specific threshold for treatment, a low hip T-score, a major osteoporotic fracture before or during bisphosphonate therapy or a new diagnosis or drug that may affect bone density, such as glucocorticoids or aromatase inhibitors.⁷

Questions to Consider

When considering a drug holiday for her patients, Dr. Hansen looks at their current FRAX and hip T-score, past adherence to therapy, whether they sustained a spine or hip fracture before or during therapy, whether their bone mineral density changed during therapy, how often they fall, and if they have any ongoing risk factors for bone loss, including glucocorticoids, cancer or weight loss. She also asks her patients about their preferences. Some are eager to stop their bisphosphonates, and others fear fracture risk and wish to continue their therapy, she said.