In a patient who completed 5 years of oral bisphosphonate and has a T score persistently in osteoporotic range, what factors help you decide whether it is appropriate to start a drug holiday vs. switch to an alternative agent?

This is an interesting question concerning a common clinical issue. Unfortunately, I am unaware of any data (evidence-based medicine) that is helpful in answering the question. My response is thus only anecdotal. There is some good data that patients with an inadequate bone density response to three years of bisphosphonate treatment can benefit from transitioning to denosumab and show good bone density gains. Because of the issue of atypical femur fractures, I am reluctant to switch to denosumab (an anti-resorptive agent) if a patient has been using a bisphosphonate for five or more years. If I consider the patient to be at increased fracture risk based on a fracture history or a very low bone density I would recommend transitioning to an a...