Bisphosphonate drug holidays: Risk of fractures and mortality in a prospective cohort study

Aminobisphosphonates: Reconsideration 25 years after their approval for the treatment of osteoporosis

Aminobisphosphonates are widely used in the treatment of osteoporosis. They have a high affinity for hydroxyapatite, binding primarily to resorbing surfaces, but also to forming surfaces and to some extent to resting surfaces. They inhibit osteoclasts, thereby decreasing remodelling units. Consequently, they increase bone mass and reduce stress risers. This decreases the risk of fractures. If this decrease is sufficient, they can be temporarily withdrawn (drug holidays), which prevents serious complications (atypical femoral fracture). They probably reduce mortality. Virtually all patients with osteoporosis can benefit from them at some point in the course of their disease (at the beginning of treatment or after the administration of anabolics, selective estrogen receptor modulators or denosumab). If well tolerated orally, alendronate and risedronate are preferable. Otherwise, zoledronate is preferred. Their efficacy vs. cost-safety-convenience ratio makes aminobisphosphonates reference drugs in the field of osteoporosis.

Low Bone Mineral Density and Calcium Levels as Risks for Mortality in Patients with Self-Discontinuation of Anti-Osteoporosis Medication

Bone mass density (BMD) has been used universally in osteoporosis diagnosis and management. Adherence to anti-osteoporosis medication is related to mortality risk. This study aimed to investigate the relationship between mortality and low BMD of the femoral neck and vertebra among patients self-discontinuing anti-osteoporosis medication. Between June 2016 and June 2018, this single-center retrospective study recruited 596 participants who self-discontinued anti-osteoporosis medication. Patients were categorized into four groups by BMD of the right femoral neck and lumbar spine. Occurrence and causes of mortality were obtained from medical records. Independent risk factors and the five-year survival of various levels of BMD were analyzed by Cox regression and the Kaplan-Meier survival analysis. BMD value and serum calcium level were significantly lower in the mortality group (p < 0.001). Compared to the reference, the adjusted hazard ratio (HR) for all-cause mortality in patients with lower BMD of both the lumbar spine and femoral neck was 3.03. The five-year cumulative survival rate was also significantly lower (25.2%, p < 0.001). A low calcium level was also associated with mortality (HR: 0.87, 95% CI: 0.76-0.99, p = 0.033). In conclusion, lower BMD and calcium levels were associated with higher mortality risk in patients with poor adherence. Hence, patients self-discontinuing anti-osteoporosis medication should be managed accordingly.

Bisphosphonate Drug Holidays in Primary Care: When and What to Do Next?

PURPOSE OF REVIEW

This review describes the rational for bisphosphonate holidays, summaries key evidence to support the concept, and provides a roadmap to help clinicians initiate, monitor, and discontinue a bisphosphonate drug holiday.

RECENT FINDINGS

Randomized trials and data from large observational studies are available to determine the short and long-term bisphosphonate benefits (prevention of fracture) and harms (principally atypical femoral fractures and osteonecrosis of the jaw). Mounting evidence points towards a causal relationship between bisphosphonate use and AFF and ONJ, particularly with > 5 years of use. Multiple studies now confirm the risk of AFF falls rapidly after BPs are discontinued. Osteoporosis patients without previous hip, vertebral, or multiple non-spine fractures who are successfully treated with oral bisphosphonates for 5 years (3 years if intravenous), should be offered a 3-5 year drug holiday, particularly if hip BMD T-score is > - 2.5. Bisphosphonates should only be continued beyond 10 years (6 years if parenteral) in patients at very high risk of fracture.