Long-term experience with alendronate in the treatment of osteoporosis

Mining and analysis of adverse event signals for alendronate based on the real-world data of FDA adverse event reporting system database

OBJECTIVE

Our study aims to assess alendronate-related adverse events (AEs) from the US FDA adverse event reporting system database.

METHODS

The AE data associated with alendronate between the first quarter of 2004 and the first quarter of 2024 were selected. Various signal quantification methods, including the ROR, PRR, BCPNN, and EBGM, were applied for analysis.

RESULTS

In 34,943 reports where alendronate was the primary suspected drug for the AE, 24 affected system organ classes and 1046 significant preferred terms were identified in this study. Several significant AEs beyond drug instructions with strong signals were determined, including low turnover osteopathy, fracture delayed union, fracture nonunion, loss of anatomical alignment after fracture reduction, fracture malunion, periprosthetic fracture, carotid bruit, oral fibroma, traumatic occlusion, and phlebolith. The median time to onset of alendronate-related AEs was 306 days (interquartile range [IQR] 12-1,461 days), and the majority of cases occurred 2 years later (18.80%) and within 30 days (14.49%).

CONCLUSIONS

The current study detected multiple potential new AE signals for alendronate, and more clinical research is required to further validate our results and clarify their associations.

Atypical subtrochanteric femoral shaft fractures: role for mechanics and bone quality

Bisphosphonates are highly effective agents for reducing osteoporotic fractures in women and men, decreasing fracture incidence at the hip and spine up to 50%. In a small subset of patients, however, these agents have recently been associated with 'atypical femoral fractures' (AFFs) in the subtrochanteric region or the diaphysis. These fractures have several atypical characteristics, including occurrence with minimal trauma; younger age than typical osteoporotic fractures; occurrence at cortical, rather than cancellous sites; early radiographic appearance similar to that of a stress fracture; transverse fracture pattern rather than the familiar spiral or transverse-oblique morphologies; initiation on the lateral cortex; and high risk of fracture on the contralateral side, at the same location as the initial fracture. Fracture is a mechanical phenomenon that occurs when the loads applied to a structure such as a long bone exceed its load-bearing capacity, either due to a single catastrophic overload (traumatic failure) or as a result of accumulated damage and crack propagation at sub-failure loads (fatigue failure). The association of AFFs with no or minimal trauma suggests a fatigue-based mechanism that depends on cortical cross-sectional geometry and tissue material properties. In the case of AFFs, bisphosphonate treatment may alter cortical tissue properties, as these agents are known to alter bone remodeling. This review discusses the use of bisphosphonates, their effects on bone remodeling, mechanics and tissue composition, their significance as an effective therapy for osteoporosis, and why these agents may increase fracture risk in a small population of patients.

Increase in bone mass after correction of vitamin D insufficiency in bisphosphonate-treated patients

OBJECTIVE

To assess the relative contribution of vitamin D insufficiency to loss of bone mineral density (BMD) in patients taking bisphosphonates.

METHODS

Patients were eligible for inclusion if they had osteoporosis or osteopenia and demonstrated a decline in BMD during the preceding year while taking stable doses of alendronate or risedronate, plus supplemental calcium and vitamin D. Patients with previously known secondary causes of osteoporosis were excluded from the study. Eligible patients underwent prospective measurement of bilateral hip and lumbar spine BMD by dual-energy x-ray absorptiometry, serum 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D, intact parathyroid hormone, osteocalcin, and thyroid-stimulating hormone (thyrotropin), and urinary calcium:creatinine ratio.

RESULTS

Annual BMD was assessed in 175 previously bisphosphonate-responsive patients with low BMD. Of the 175 patients, 136 (78%) had either a significant interval increase or no change in BMD, whereas 39 (22%) had a significant decrease. Of the 39 patients who lost BMD, 20 (51%) had vitamin D insufficiency (25-OHD <30 ng/mL). After a single course of orally administered vitamin D2 (500,000 IU during a 5-week period), the 25-OHD level returned to normal in 17 of the 20 vitamin D-insufficient patients and was associated with significant (P<.02) 3.0% and 2.7% increases in BMD at the lumbar spine and the femoral neck, respectively. Failure to normalize the serum 25-OHD level was associated with further loss of BMD.

CONCLUSION

Vitamin D insufficiency was the most frequently identified cause of bone loss in patients with declining BMD during bisphosphonate therapy. Correction of vitamin D insufficiency in these patients led to a significant rebound in BMD.

Alendronate therapy in cyclosporine-induced alveolar bone loss in rats

BACKGROUND AND OBJECTIVE

Cyclosporine A is an immunosuppressive drug that is widely used in organ transplant patients as well as to treat a number of autoimmune conditions. Bone loss is reported as a significant side-effect of cyclosporine A use because this can result in serious morbidity of the patients. As we have shown that cyclosporine A-associated bone loss can also affect the alveolar bone, the purpose of this study was to evaluate the effect of the concomitant administration of alendronate on alveolar bone loss in a rat model.

MATERIAL AND METHODS

Forty Wistar rats (10 per group) were given cyclosporine A (10 mg/kg, daily), alendronate (0.3 mg/kg, weekly), or both cyclosporine A and alendronate, for 60 d. The control group received daily injections of sterile saline. The expression of proteins associated with bone turnover, including osteocalcin, alkaline phosphatase and tartrate-resistant acid phosphatase (TRAP), and also the calcium levels, were evaluated in the serum. Analysis of the bone volume, alveolar bone surface, the number of osteoblasts per bone surface and the number of osteoclasts per bone surface around the lower first molars was also performed.

RESULTS

The results indicate that cyclosporine A treatment was associated with bone resorption, represented by a decrease in the bone volume, alveolar bone surface and the number of osteoblasts per bone surface and by an increase in the number of osteoclasts per bone surface and TRAP-5b. These effects were effectively counteracted by concomitant alendronate administration.

CONCLUSION

It is concluded that concomitant administration of alendronate can prevent cyclosporine A-associated alveolar bone loss.

Treatment with alendronate plus calcium, alendronate alone, or calcium alone for postmenopausal low bone mineral density

OBJECTIVE

Bisphosphonates such as alendronate are widely used for postmenopausal osteoporosis. Supplemental calcium is also generally recommended. This trial directly compares alendronate to supplemental calcium and examines the effect of calcium supplementation on alendronate treatment.

METHODS

This 2-year, randomized, double-blind, multicenter trial enrolled healthy, postmenopausal women with low bone mineral density (BMD). Patients with a dietary calcium intake > or = 800 mg/day received daily vitamin D 400 IU and alendronate 10 mg/calcium-placebo, alendronate 10 mg/elemental calcium 1000 mg, or alendronate-placebo/calcium 1000 mg (2:2:1). Endpoints included BMD, bone turnover markers (BTMs), and adverse events.

RESULTS

Randomized patients (N = 701) were an average of 20.4 years postmenopausal. After 24 months, increases in lumbar spine BMD differed significantly between patients receiving calcium alone (0.8%) and either alendronate alone (5.6%) or alendronate + calcium (6.0%) (p < 0.001). Significant differences were also seen at the trochanter and femoral neck (p < 0.001). BTMs were significantly lower with alendronate-containing treatments than calcium alone (p < 0.001). Addition of calcium supplementation to alendronate did not significantly increase BMD compared to alendronate alone (p = 0.29 to 0.97), but did result in a statistically significant, though small, additional reduction in urinary NTx. Adverse events were similar among treatment groups. Limitations include no assessment of vitamin D levels and a discontinuation rate of approximately 30%, although discontinuation rates were similar among treatment groups.

CONCLUSIONS

In postmenopausal women with a daily intake of > or =800 mg calcium and 400 IU vitamin D, 24-month treatment with alendronate 10 mg daily with or without calcium 1000 mg resulted in significantly greater increases in BMD and reduction of bone turnover than supplemental calcium alone. Addition of supplemental calcium to alendronate treatment had no effect on BMD and resulted in a small, though statistically significant, additional reduction in NTx.