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

Bisphosphonate drug holidays in osteoporosis according to fracture risk profile

We analyzed the incidence of fractures and changes in bone mineral density and bone turnover markers in 264 patients who discontinued bisphosphonates. Fractures were recorded in 12.3%. Half were clinical vertebral fractures. We identified patients with a high-risk profile who should not discontinue treatment.

OBJECTIVE

The optimal length of bisphosphonate discontinuation is unknown, as is the type of patient who could benefit from this approach. The objectives of the study were to analyze, in clinical practice, the incidence of fractures and associated risk factors, changes in bone mineral density (BMD) and bone turnover markers (BTMs) after discontinuation of bisphosphonates.

METHODS

This observational retrospective study included 264 patients from 14 Spanish rheumatology departments. Postmenopausal women or men with osteoporosis received alendronate or risedronate for ≥ 5 years or zoledronate for ≥ 3 years and had discontinued treatment for ≥ 1 year or ≥ 2 years, respectively. Spinal X-rays were obtained before discontinuation and in suspected clinical vertebral fracture during follow-up. BMD and BTMs were determined before discontinuation and at different time points.

RESULTS

The mean discontinuation time was 2.7 (± 6.7) years. Thirty-two patients (12.3%) had 36 fractures, mainly clinical vertebral fractures. The main risk factor for fracture was a high-risk profile (femoral neck T-score ≤ -2.5 and/or a history of fracture and/or multiple fractures [≥ 5 years]) before discontinuation. At 12 months, 10.41% of patients with high-risk profile experienced a fracture, being 0.8% and 1.08% in moderate- and low-risk patients, respectively. Significant BMD loss at the femoral neck and total hip was detected, with duration of discontinuation being the key factor. PINP was the marker with the greatest changes.

CONCLUSIONS

We identified a profile of patients with osteoporosis who should not discontinue bisphosphonates, owing to the possibility of fractures, especially vertebral, which are already evident the first year after discontinuation.

Effect of Oral Bisphosphonate Drug Holiday on Mortality Following Hip Fracture

CONTEXT

Current clinical guidelines recommend a drug holiday after extended use of oral bisphosphonates. However, no studies have investigated the effect of drug holidays before hip fractures on postfracture mortality.

OBJECTIVE

This work aimed to investigate the effect of a drug holiday on postfracture mortality in patients with extended use of oral bisphosphonates.

METHODS

This retrospective, population-based cohort study took place among all patients with hip fractures in Victoria, Australia, from 2014 to 2018. Patients were adherent to oral alendronate or risedronate for 5 years or more prior to hip fracture. Group-based trajectory modeling categorized patients into different bisphosphonate usage after 5-year good adherence. The main outcome measure was postfracture mortality.

RESULTS

We identified 365 patients with good adherence (medication possession ratio ≥80%) to oral alendronate/risedronate for 5 years or more. Most patients (69%) continued to use oral bisphosphonates until admission for hip fracture; 17% had discontinued for 1 year and 14% had discontinued for 2 years. Postfracture mortality was higher in patients who had discontinued risedronate for 1 year (hazard ratio [HR] 2.37; 95% CI, 1.24-4.53) and 2 years (HR 3.08; 95% CI, 1.48-6.41) prior to hip fracture. No increase or decrease in postfracture mortality was observed in patients who had discontinued alendronate for 1 year (HR 0.59; 95% CI, 0.29-1.18) or 2 years (HR 1.05; 95% CI, 0.57-1.93) prior to hip fracture.

CONCLUSION

Postfracture mortality is higher in people who discontinue risedronate, but not alendronate, for 1 or 2 years after being adherent to treatment for at least 5 years. The type of bisphosphonate may be a factor to consider when planning drug holidays.

Prevention of chemotherapy-related bone loss with doxorubicin-loaded solid lipid nanoparticles

Aim: Breast cancer and its metastases involve high mortality even with advances in chemotherapy. Solid lipid nanoparticles provide a platform for drug delivery, reducing side effects and treatment-induced bone loss. A solid nanoparticle containing doxorubicin was evaluated for its ability to prevent bone loss in a pre-clinical breast cancer model.Methods: We investigated the effects of SLNDox in an aggressive metastatic stage IV breast cancer model, which has some important features that are interesting for bone loss investigation. This study evaluates bone loss prevention potential from solid lipid nanoparticles containing doxorubicin breast cancer treatment, an evaluation of the attenuation of morphological changes in bone tissue caused by the treatment and the disease and an assessment of bone loss imaging using computed tomography and electron microscopy.Results: Chemotherapy-induced bone loss was also observed in tumor-free animals; a solid lipid nanoparticle containing doxorubicin prevented damage to the growth plate and to compact and cancellous bones in the femur of tumor-bearing and healthy animals.Conclusion: The association of solid lipid nanoparticles with chemotherapeutic drugs with proven efficacy promotes the prevention of serious consequences of chemotherapy, reducing tumor progression, increasing quality of life and improving prognosis and survival.

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.