For high risk patients, published recommendations suggest treating for 10 years, then discontinuing treatment for 1-2 years (or less if bone mineral density decreases or fracture occurs). An alternate medication, such as teriparatide, if warranted, can be used in these patients during the bisphosphonate holiday, she said.
Findings from recent trials, including the Long-term Extension (FLEX) of the Fracture Intervention Trial (FIT), and the HORIZON trial suggest that 3-5 years of treatment may be sufficient unless there is a high risk for vertebral fracture, in which case treatment should potentially continue for up to 6-10 years.
“Consider avoiding the use of an antiresorptive agent during the drug holiday,” Dr. Bolster said, explaining that although it has yet to be determined, there is concern that the atypical femoral fractures may result from prolonged inhibition of bone turnover that occurs with antiresorptive therapy, so it may not make sense to add an antiresorptive agent during a bisphosphonate holiday.
This area, however, clearly warrants further study, she noted.
During 1-2 years of a drug holiday, fracture protection appears to persist, and the risk of atypical femoral fractures decreases rapidly, she added.
When deciding how long a drug holiday should last, consider the utility of bone turnover markers, she also suggested. Bone turnover marker use in treatment decision making, however, also warrants further investigation.
There is a lack of standardization with these markers, and they may be affected by other conditions and medication, but the International Osteoporosis Foundation endorses serum C-terminal telopeptide of type 1 collagen and serum procollagen type 1 N-terminal propeptide.
Using bone turnover makers along with a DXA scan may be helpful in determining the appropriate duration of a drug holiday, but more knowledge in this field is needed, Dr. Bolster said at the meeting held by Global Academy for Medical Education. Global Academy for Medical Education and this news organization are owned by Frontline Medical Communications.
In essence, the decision should be individualized based on age, compliance, treatment duration, risk factors, and risk of vertebral fractures, and these factors should be reassessed regularly, she said.
Dr. Bolster reported that she has worked on a clinical trial for Eli Lilly, received fellowship program grant support from Amgen and AbbVie in salary support for a first-year rheumatology fellow, has investments in Johnson and Johnson, has served on committees for American College of Rheumatology, American Board of Internal Medicine, and the International Society for Clinical Densitometry, and as a board member for ACR and Rheumatology Research Foundation.