Bisphosphonate ‘Drug Holidays’ Don’t Raise Fracture Risk in Women With Osteoporosis

Drug holidays from bisphosphonates appear to be safe for women with osteoporosis, according to new data presented at the American Society for Bone and Mineral Research (ASBMR) 2014 Annual Meeting.

In a retrospective cohort study, researchers evaluated fragility fractures related to osteoporosis between two groups of women: those who took a drug holiday from bisphosphonates, defined as discontinuation of treatment for at least 12 months, and those who had persistent use, defined as continued bisphophonate use with at least 50% adherence to treatment.

First clinical osteoporosis-related fragility fracture served as the primary outcome. Electronic medical records (EMRs) were used to collect this information.

A total of 3,751 osteoporosis-related fractures occurred among 28,620 women — 17,123 of whom did not take drug holidays and 11,497 of whom did take drug holidays — during 111,997 person-years of follow-up, the researchers reported.

Compared with persistent use, drug holiday was associated with an unadjusted rate ratio of 0.87 (95% CI, 0.81-0.94) for fractures related to osteoporosis. For hip fractures only, the rate ratio was 1.0 (95% CI, 0.9-1.2), according to the study results.

Time-varying models indicated no differences in risks for any fracture or hip fractures only, with hazard ratios (HRs) for any osteoporosis-related fracture and hip fracture of 0.90 (95% CI, 0.80-1.00) and 0.84 (95% CI, 0.68-1.03), respectively, after adjustments for baseline fall and fracture risk, comorbidities and other bone-active medication use.

Women aged 45 years or older from four Kaiser Permanente regions with at least 3 years exposure to bisphosphonates were included in the study. The researchers noted fewer comorbidities, higher baseline T-scores, and lower fracture and fall risk scores among those who took drug holidays.

“Women who undertake a holiday from [bisphophonate] use are not at greater risk of osteoporosis-related fragility fractures, nor hip fractures specifically, than are women who continue to use [bisphosphonates] persistently,” the researchers wrote in their abstract.

Reference

1. Adams A et al. Abstract 1045. Presented at: American Society of Bone and Mineral Research 2014 Annual Meeting; Sept. 12-15, 2014; Houston, Texas.