Bisphosphonate drug ‘holidays’ increase fracture risk in women

Discontinuing the use of bisphosphonates for more than 2 years has been linked to increase risk for hip fracture in women, according to research presented at the ASBMR 2018 annual meeting.

“Knowing whether to put people on a bisphosphonate drug holiday, and for how long, is probably one of the leading questions in the bone field facing clinicians these days,” Jeffrey Curtis, MD, MS, MPH, Harbert-Ball endowed professor of medicine in the division of clinical immunology and rheumatology at the University of Alabama at Birmingham, told Endocrine Today. “It’s unlikely that we will have a large-scale clinical trial to answer this question.”

Curtis and colleagues reviewed Medicare data collected between 2006 and 2015 from 160,369 women who began bisphosphonate treatment for at least 3 years. All participants had an 80% or higher adherence rate. Among those women, 36% stopped taking bisphosphonates for a year or longer.

All participants returned for follow-up after a median of 2.7 years (range, 1.5-4.1 years). Researchers found that hip fracture rates were statistically significantly higher for those who took a “drug holiday” than those who continued treatment. Women who discontinued bisphosphonate use for 2 or more years experienced 4,823 reported hip fractures, for an adjusted HR of 1.22 (95% CI, 1.11-1.34) compared with those who used bisphosphonate drugs continuously.

“We need a better understanding of the optimal duration of a drug holiday depending on how long people have been on bisphosphonates. In our study, the minimum use was 3 years, and people had received somewhat more therapy (eg, 4-5 years) before they took a drug holiday, but for someone who has been on a bisphosphonate a very long time (eg, > 5 years), they might be able to take a longer drug holiday,” Curtis said. “We also need a better understanding on how to contextualize the benefits and risks of a drug holiday against other safety concerns for continued bisphosphonate use, including osteonecrosis of the jaw and atypical femoral shaft fractures.” – by Phil Neuffer

Reference:

Curtis J, et al. Abstract 1006. Presented at: American Society for Bone and Mineral Research Annual Meeting; Sept. 28-Oct. 1, 2018; Montreal.

Disclosures: Curtis reports he is a consultant for Amgen and Radius. Please see the study for all other authors’ relevant financial disclosures.