Effectiveness of bisphosphonates on nonvertebral and hip fractures in the first year of therapy: the risedronate and alendronate (REAL) 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 If this decrease is sufficient, they can be temporarily withdrawn (drug holidays), which prevents serious complications (atypical femoral fracture).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.

Effects of risedronate, alendronate, and minodronate alone or in combination with eldecalcitol on bone mineral density, quality, and strength in ovariectomized rats

Combination therapy of active vitamin D₃ with some bisphosphonates (BPs) has been reported to be clinically beneficial. However, combination therapy of eldecalcitol (ELD) with BP has to date not been validated as to whether it is beneficial in the clinical setting. Preclinical studies suggested that simultaneous treatment with ELD and some BPs is more effective than monotherapy. However, the relative potency of various BPs, when used in combination with ELD, is completely unknown. In this study, we examined and compared the effects of risedronate (RIS), alendronate (ALN), and minodronate (MIN) alone or in combination with ELD on bone mass, microarchitecture, strength, and material properties in ovariectomized Sprague-Dawley rats aged 13 weeks. RIS, ALN, MIN, and ELD were administered five times weekly for 16 weeks. Micro-computed tomography analysis, compression test, and Fourier transform infrared (FTIR) imaging analysis were performed 16 weeks after treatment initiation. Trabecular and cortical bone mineral density (BMD) in the fourth lumbar vertebra (L4) significantly increased in the RIS + ELD, ALN + ELD, and MIN + ELD groups compared with the vehicle group. Moreover, the bone microarchitecture of L4 in all the BP + ELD groups also significantly improved. On mechanical testing of L4, the maximum load was significantly increased in the RIS + ELD and ALN + ELD groups. FTIR analysis revealed that the mineral-to-collagen ratio of trabecular bone in L3 of all the BP + ELD groups was significantly increased compared with the vehicle group. By contrast, the carbonate-to-phosphate ratio, a parameter of mineral immaturity, was significantly decreased in the RIS + ELD and ALN + ELD groups. BP + ELD improved the BMD and structural properties of the bone to a similar extent. RIS + ELD and ALN + ELD also improved bone strength. Furthermore, treatment with BP + ELD improved the bone material. These results suggest that the combination therapy of BP and ELD is beneficial and warrants further clinical trials.

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Combination of bisphosphonates and eldecalcitol was superior to either monotherapy.

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Bone quality on FTIR imaging analysis correlated with bone strength.

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Combined bisphosphonate and eldecalcitol may be useful in the clinical setting.

Fracture risk following intermission of osteoporosis therapy

Given the widespread practice of recommending drug holidays, we reviewed the impact of medication discontinuation of two common anti-osteoporosis therapies (bisphosphonates and denosumab). Trial evidence suggests the risk of new clinical fractures, and vertebral fracture increases when osteoporosis treatment with bisphosphonates or denosumab is stopped.

INTRODUCTION

The aim of this paper was to review the available literature to assess what evidence exists to inform clinical decision-making with regard to drug holidays following treatment with bisphosphonates (BiP) or denosumab.

METHODS

Systematic review.

RESULTS

Differing pharmacokinetics lead to varying outcomes on stopping therapy. Prospective and retrospective analyses report that the risk of new clinical fractures was 20-40% higher in subjects who stopped BiP treatment, and vertebral fracture risk was approximately doubled. Rapid bone loss has been well described following denosumab discontinuation with an incidence of multiple vertebral fractures around 5%. Studies have not identified risk factors for fracture after stopping treatment other than those that provide an indication for treatment (e.g. prior fracture and low BMD). Studies that considered long-term continuation did not identify increased fracture risk, and reported only very low rates of adverse skeletal events such as atypical femoral fracture.

CONCLUSIONS

The view that patients on long-term treatment with bisphosphonates or denosumab should always be offered a drug holiday is not supported by the existing evidence. Different pharmacokinetic properties for different therapies require different strategies to manage drug intermission. In contrast, long-term treatment with anti-resorptives is not associated with increased risk of fragility fractures and skeletal adverse events remain rare.

Anorexia Nervosa and Osteoporosis: Pathophysiology and Treatment

Anorexia nervosa (AN) affects 2.9 million people, many of whom experience bone loss and increased fracture risk. In this article, we review data on the underlying pathophysiology of AN-related osteoporosis and possible approaches to disease management. Available research suggests that low body weight and decreased gonadal function are the strongest predictors of bone loss and fractures in patients with AN. Additionally, other metabolic disturbances have been linked to bone loss, including growth hormone resistance, low leptin concentrations, and hypercortisolemia, but those correlations are less consistent and lack evidence of causality. In terms of treatment of AN-related bone disease, weight gain has the most robust impact on bone mineral density (BMD). Restoration of gonadal function seems to augment this effect and may independently improve BMD. Bisphosphonates, insulin-like growth factor 1 supplementation, and teriparatide may also be reasonable considerations, however need long-term efficacy and safety data.

Advances and Unmet Needs in the Therapeutics of Bone Fragility

The prevalence of fragility fractures increases as longevity increases the proportion of the elderly in the community. Until recently, the majority of studies have targeted women with osteoporosis defined as a bone mineral density (BMD) T score of < -2.5 SD, despite evidence that the population burden of fractures arises from women with osteopenia. Antiresorptive agents reduce vertebral and hip fracture risk by ~50 percent during 3 years but efficacy against non-vertebral fractures, 80% of all fractures in the community, is reported in few studies, and of those, the risk reduction is only 20-30%. Recent advances in the use of antiresorptives and anabolic agents has addressed some of these unmet needs. Zoledronic acid is now reported to reduce vertebral and non-vertebral fractures rates in women with osteopenia. Studies using teriparatide demonstrate better vertebral and clinical (symptomatic vertebral and non-vertebral) antifracture efficacy than risedronate. Abaloparatide, a peptide sharing amino acid sequences with teriparatide, reduces vertebral and non-vertebral fractures. Romosozumab, a monoclonal antibody suppressing sclerostin, reduces vertebral and non-vertebral fractures within a year of starting treatment, and does so more greatly than alendronate. Some recent studies signal undesirable effects of therapy but provide essential cautionary insights into long term management. Cessation of denosumab is associated with a rapid increase in bone remodeling and the uncommon but clinically important observation of increased multiple vertebral fractures suggesting the need to start alternative anti-resorptive therapy around the time of stopping denosumab. Antiresorptives like bisphosphonates and denosumab suppress remodeling but not completely. Antifracture efficacy may be limited, in part, as a consequence of continued unsuppressed remodeling, particularly in cortical bone. Bisphosphonates may not distribute in deeper cortical bone, so unbalanced intracortical remodeling continues to cause microstructural deterioration. In addition, suppressed remodeling may compromise the material composition by increasing matrix mineral density and glycosylation of collagen. As antiresorptive agents do not restore microstructural deterioration existing at the time of starting treatment, under some circumstances, anabolic therapy may be more appropriate first line treatment. Combining antiresorptive and anabolic therapy is an alternative but whether anti-fracture efficacy is greater than that achieved by either treatment alone is not known.

Aminobisphosphonates based on cyclohexane backbone as coordinating agents for metal ions. Thermodynamic, spectroscopic and biological studies

Complex formation equilibria of calcium, magnesium, copper and nickel with amino-bisphosphonic ligands are described, together with a speciation study along with calorimetric outcome and cytotoxicity characteristics.

Effect of Sequential Treatment with Bisphosphonates After Teriparatide in Ovariectomized Rats: A Direct Comparison Between Risedronate and Alendronate

Teriparatide (TPTD), a recombinant human parathyroid hormone N-terminal fragment (1-34), is a widely used bone anabolic drug for osteoporosis. Sequential treatment with antiresorptives such as bisphosphonates after TPTD discontinuation is generally recommended. However, relative effects of bisphosphonates have not been determined. In the present study, we directly compared effects of risedronate (RIS) and alendronate (ALN) on bone mineral density (BMD), bone turnover, structural property and strength in ovariectomized (OVX) rats, when administered after TPTD. Female Sprague Dawley rats were divided into one sham-operated and eight ovariectomized groups. TPTD, RIS, and ALN were given subcutaneously twice per week for 4 or 8 weeks after 4 week treatment with TPTD. TPTD significantly increased BMD (+9.6%) in OVX rats after 4 weeks of treatment. 8 weeks after TPTD withdrawal, vehicle-treated group showed a blunted BMD increase of +8.4% from the baseline. In contrast, 8 weeks of treatment with RIS and ALN significantly increased BMD to 17.4 and 21.8%, respectively. While ALN caused a consistently larger increase in BMD, sequential treatment with RIS resulted in lower Tb.Sp compared to ALN in the fourth lumbar vertebra as well as in greater stiffness in compression test. In conclusion, the present study demonstrated that sequential therapy with ALN and RIS after TPTD both improved bone mass and structure. Our results further suggest that RIS may have a greater effect on improving bone quality and stiffness than ALN despite less prominent effect on BMD. Further studies are necessary to determine clinical relevance of these findings to fracture rate.

Risk of hip fracture following a wrist fracture-A meta-analysis

AIMS

This purpose of this meta analysis was to investigate and quantify the relative risk of hip fracture in patients who have sustained a wrist fracture.

METHOD

Studies were identified by searching Medline, Embase, Cochrane CENTRAL database and CINAHL from their inception to August 2015. Studies reporting confirmed hip fracture following wrist fracture were included. Data extraction was carried out using a modified Cochrane data collection form by two reviewers independently. Quality assessment was carried out using a modified Coleman score and the Newcastle Ottawa scale for cohort studies. An assessment of bias was performed for each study using a modified Cochrane Risk of Bias tool. A pooled relative risk(RR) was estimated with 95% CI from the RR/HRs and CIs reported in the studies.

RESULTS

12 studies were included in the final meta-analysis (4 male, 8 female only). Relative risk of hip fracture following wrist fracture for women was 1.43 (CI 1.27 to 1.60). In men it was not significantly increased (RR 2.11, 95% CI: 0.93-4.85). Heterogeneity was low (I squared 0%) for both groups so a fixed effects model was used.

CONCLUSION

Risk of a subsequent hip fracture is increased for women who suffer a wrist fracture (RR 1.43). Resources and preventative measures should be targeted towards these high risk patients to prevent the catastrophic event of a hip fracture. This meta analysis confirms and quantifies the increased relative risk of hip fracture after wrist fracture in women.

Exploring methods for comparing the real-world effectiveness of treatments for osteoporosis: adjusted direct comparisons versus using patients as their own control

Using Swedish and Dutch registry data for women initiating bisphosphonates, we evaluated two methods of comparing the real-world effectiveness of osteoporosis treatments that attempt to adjust for differences in patient baseline characteristics. Each method has advantages and disadvantages; both are potential complements to clinical trial analyses.

PURPOSE

We evaluated methods of comparing the real-world effectiveness of osteoporosis treatments that attempt to adjust for both observed and unobserved confounding.

METHODS

Swedish and Dutch registry data for women initiating zoledronate or oral bisphosphonates (OBPs; alendronate/risedronate) were used; the primary outcome was fracture. In adjusted direct comparisons (ADCs), regression and matching techniques were used to account for baseline differences in known risk factors for fracture (e.g., age, previous fracture, comorbidities). In an own-control analysis (OCA), for each treatment, fracture incidence in the first 90 days following treatment initiation (the baseline risk period) was compared with fracture incidence in the 1-year period starting 91 days after treatment initiation (the treatment exposure period).

RESULTS

In total, 1196 and 149 women initiating zoledronate and 14,764 and 25,058 initiating OBPs were eligible in the Swedish and Dutch registries, respectively. Owing to the small Dutch zoledronate sample, only the Swedish data were used to compare fracture incidences between treatment groups. ADCs showed a numerically higher fracture incidence in the zoledronate than in the OBPs group (hazard ratio 1.09-1.21; not statistically significant, p > 0.05). For both treatment groups, OCA showed a higher fracture incidence in the baseline risk period than in the treatment exposure period, indicating a treatment effect. OCA showed a similar or greater effect in the zoledronate group compared with the OBPs group.

CONCLUSIONS

ADC and OCA each possesses advantages and disadvantages. Combining both methods may provide an estimate of real-world treatment efficacy that could potentially complement clinical trial findings.

Does bisphosphonate-based anti-osteoporosis medication affect osteoporotic spinal fracture healing?

Effects of bisphosphonate on fracture healing were prospectively investigated for osteoporotic spinal fracture. Although there were no significant differences in clinical outcomes, the presence of intravertebral cleft was related to the medication use. These results suggest that suspension of bisphosphonate use should be considered during the fracture healing period.

INTRODUCTION

The purpose of this prospective study is to investigate whether bisphosphonate-based anti-osteoporosis medication affects fracture healing and clinical outcomes of conservatively treated osteoporotic spinal fractures (OSFs).

METHODS

A total of 105 patients who were diagnosed with acute OSFs were prospectively enrolled. According to their previous medication history, the patients were allocated into group I (n = 39, no history of bisphosphonate use) or group II (n = 66, history of bisphosphonate use). Clinical outcomes were assessed using visual analogue scale (VAS), and Oswestry disability index (ODI). Radiographic parameters including changes in height loss and kyphotic angle at the index vertebra were measured, and radiographic findings suggesting impaired fracture healing such as the intravertebral cleft (IVC) sign and fracture instability were evaluated. Univariate and multivariate regression analyses were used to identify related factors.

RESULTS

There were no significant differences in the last VAS and ODI between groups. There were also no significant differences in the radiographic parameters. Although the IVC sign was seen more commonly in group II (30.3 %) than in group I (20.5 %), fracture instability combined with IVC was noted in the same number of cases. On multiple regression analysis, medication history showed no significant relationship with the clinical parameters. However, the presence of the IVC sign was related to medication history (odds ratio 4.8; 95 % confidence interval [CI] 1.02-22.69).

CONCLUSIONS

Bisphosphonate use does not significantly affect the clinical results during conservative treatment for OSFs. However, the occurrence of the IVC sign was related to medication history. Although further studies are needed to verify our findings, these results suggest that suspension of bisphosphonate use should be considered during the fracture healing period for acute OSFs.

Effects of switching weekly alendronate or risedronate to monthly minodronate in patients with rheumatoid arthritis: a 12-month prospective study

Switching weekly ALN or RIS to monthly MIN in patients with RA, of whom two-thirds were treated with low-dose PSL, significantly decreased bone turnover markers and increased BMD at 12 months, suggesting that monthly MIN may be an effective alternative treatment option of oral bisphosphonate treatment.

INTRODUCTION

The aim of this prospective, observational study was to evaluate the effects of switching weekly alendronate (ALN 35 mg) or risedronate (RIS 17.5 mg) to monthly minodronate (MIN 50 mg) in patients with rheumatoid arthritis (RA).

METHODS

Patient characteristics were as follows: n = 172; 155 postmenopausal women, age 65.5 (44–87) years; T-score of lumbar spine (LS), −1.4; total hip (TH), −1.8; femoral neck (FN), −2.1; dose and rate of oral prednisolone (2.3 mg/day), 69.1 %; prior duration of ALN or RIS, 46.6 months; were allocated, based on their preference, to either the (1) continue group (n = 88), (2) switch-from-ALN group (n = 44), or (3) switch-from-RIS group (n = 40).

RESULTS

After 12 months, increase in BMD was significantly greater in group 3 compared to group 1: LS (4.1 vs 1.2 %; P < 0.001), TH (1.9 vs −0.7 %; P < 0.01), and FN (2.7 vs −0.5 %; P < 0.05); and in group 2 compared to group 1: LS (3.2 vs 1.2 %; P < 0.05) and TH (1.5 vs −0.7 %; P < 0.01). The decrease in bone turnover markers was significantly greater in group 3 compared to group 1: TRACP-5b (−37.3 vs 2.5 %; P < 0.001), PINP (−24.7 vs −6.2 %; P < 0.05), and ucOC (−39.2 vs 13.0 %; P < 0.05); and in group 2 compared to group 1: TRACP-5b (−12.5 vs 2.5 %; P < 0.05) at 12 months.

CONCLUSIONS

Switching weekly ALN or RIS to monthly MIN in patients with RA may be an effective alternative treatment option of oral bisphosphonate treatment.

Is it the time to rethink clinical decision-making strategies? From a single clinical outcome evaluation to a Clinical Multi-criteria Decision Assessment (CMDA)

There are plenty of different clinical, organizational and economic parameters to consider in order having a complete assessment of the total impact of a pharmaceutical treatment. In the attempt to follow, a holistic approach aimed to provide an evaluation embracing all clinical parameters in order to choose the best treatments, it is necessary to compare and weight multiple criteria. Therefore, a change is required: we need to move from a decision-making context based on the assessment of one single criteria towards a transparent and systematic framework enabling decision makers to assess all relevant parameters simultaneously in order to choose the best treatment to use. In order to apply the MCDA methodology to clinical decision making the best pharmaceutical treatment (or medical devices) to use to treat a specific pathology, we suggest a specific application of the Multiple Criteria Decision Analysis for the purpose, like a Clinical Multi-criteria Decision Assessment CMDA. In CMDA, results from both meta-analysis and observational studies are used by a clinical consensus after attributing weights to specific domains and related parameters. The decision will result from a related comparison of all consequences (i.e., efficacy, safety, adherence, administration route) existing behind the choice to use a specific pharmacological treatment. The match will yield a score (in absolute value) that link each parameter with a specific intervention, and then a final score for each treatment. The higher is the final score; the most appropriate is the intervention to treat disease considering all criteria (domain an parameters). The results will allow the physician to evaluate the best clinical treatment for his patients considering at the same time all relevant criteria such as clinical effectiveness for all parameters and administration route. The use of CMDA model will yield a clear and complete indication of the best pharmaceutical treatment to use for patients, helping physicians to choose drugs with a complete set of information, imputed in the model.

Medication use before and after hip fracture: a population-based cohort and case-control study

BACKGROUND

Osteoporosis, together with age, is the main risk factor for hip fracture, the incidence of which has also been associated with an increased risk of falling or co-morbidities and related pharmacological treatments.

OBJECTIVES

The aim of this study was to investigate changes in concomitant pharmacological treatments prescribed before and after hip fracture in elderly patients compared with treatments prescribed to a matched cohort of subjects without hospitalisation for fractures.

METHODS

Data relating to the study population were extracted from a large population-based administrative database of the Italian National Health Authorities. A retrospective analysis was conducted involving female patients (6,431) aged ≥65 years and hospitalised for a hip fracture. The control group comprised age-matched subjects (38,586) not hospitalised for fracture. Changes in drug prescriptions 1 year before and 1 year after hip fracture and differences versus controls were compared.

RESULTS

Prior to the fracture, patients were taking more anti-Parkinson medications, antidepressants, medications for chronic obstructive pulmonary disease (COPD), bisphosphonates and calcium-vitamin D supplements, although the intake of the routinely monitored drug classes was significantly infrequent. Polypharmacy was less frequent in fractured women before fracture than in controls (22 vs. 25 %, respectively; P < 0.001), but it was more frequent (30 %, P < 0.001) post-fracture. The incidence of fracture was associated with a significant increase in the use of a number of drug classes: insulin, NSAIDs or analgesics, gastroprotectants, loop diuretics, β-blockers, antidepressants, antiparkinson drugs, antiepileptics and drugs for COPD.

CONCLUSION

Our study confirms a strong association between the use of some drugs (antidepressants, antiparkinson drugs, drugs for COPD) and the risk of hip fracture, but drug use is globally less common than in controls. Hip fracture is associated with a significant increase in drug use, suggesting a global deterioration of health conditions.

Risedronate improves bone architecture and strength faster than alendronate in ovariectomized rats on a low-calcium diet

Clinical evidence suggests that, compared with alendronate, risedronate reduces fracture risk faster and more potently, with less bone mass gain. We tested the hypothesis that risedronate improves bone quality faster than alendronate using calcium-deficient, ovariectomized (OVX) rats. Female Sprague-Dawley rats at 24 weeks of age were divided into sham-operated and OVX groups and fed a low-calcium (0.05%) diet under paired feeding. After 12 weeks, OVX rats were divided into five groups and treated with vehicle, risedronate (3.5 and 17.5 μg/kg/week, s.c.) or alendronate (7 and 35 μg/kg/week, s.c.). Rats were killed 6-8 weeks later and the bone architecture and strength of the left femur were evaluated by micro-computed tomography and a three-point bending test. Trabecular bone mineral density (BMD), number and thickness were significantly lower in OVX rats than in the sham-operated group. Cortical BMD, bone area (Ct.Ar), and thickness (Ct.Th) were similarly decreased. Risedronate significantly improved Ct.Ar (+8%) and Ct.Th (+9%) at 6 weeks, while alendronate only caused a significant improvement in Ct.Ar (+8% at 6 weeks) and only at the higher dose. At 8 weeks, both risedronate and alendronate significantly increased trabecular BMD compared with the vehicle. Bone strength parameters showed a significant correlation between Ct.Ar and Ct.Th. Risedronate significantly improved maximum load at 6 weeks, while alendronate failed to produce any significant changes. Our results suggest that risedronate is superior to alendronate at improving cortical bone architecture and strength, and that enhanced bone quality partly accounts for risedronate's efficacy.

Updates on mechanism of action and clinical efficacy of risedronate in osteoporosis

Risedronate is a heterocyclic orally active aminobisphosphonate and it belongs to the bisphosphonate category: these drugs are powerful bone resorption inhibitors, thanks to their affinity for hydroxyapatite crystals at bone mineral matrix level and to their inhibiting effects on osteoclast activity, using the ability of inhibiting enzyme FPPS. Recent observations have reported that risedronate can decrease resorption entity, not only of the trabecular bone, but also of the cortical bone, modifying therefore the (bone compact) thickness and the cortical porosity entity, which is largely responsible of femoral fracture especially among elderly patients. Various controlled studies have proved the efficacy of risedronate in reducing fragility fracture risk significantly. In particular, it is able to lower in a very significant way the incidence of vertebral, non-vertebral and femoral fractures, with precocity of effects after only six months of therapy. The extension of protocols, moreover, has marked its efficacy even after seven years of treatment. Under the metabolic profile, these studies have also shown that risedronate activity can reduce bone resorption markers and increase bone density values at lumbar and femoral level. Results emerged from a group of women aged over 80 are relevant: risedronate has proved capable of decreasing femoral fracture risk. Also in male and steroidal osteoporosis, clinical controlled studies have shown that risedronate is effective in decreasing vertebral fracture incidence. Lastly, tolerability: the main side effects concern the gastrointestinal tract and they are usually rare, of minor entity and can be solved by sospending the treatment. Acute phase reaction is rare, due to risedronate oral administration; it is also valid for osteonecrosis of the jaw and atypical fractures.

Effects of clodronate and alendronate on osteoclast and osteoblast co-cultures on silk-hydroxyapatite films

The goal of this study was to explore the effects of osteoporosis-related therapeutics on bone remodeling in vitro. A previously established bone-tissue mimetic system consisting of silk protein biomaterials in combination with hydroxyapatite and human cells was used for the study. Silk-hydroxyapatite films were pre-complexed with the non-nitrogenous bisphosphonate clodronate or the nitrogenous bisphosphonate alendronate and cultured with THP-1 human acute monocytic leukemia cell line-derived osteoclasts, human mesenchymal stem cell derived osteoblasts or a direct co-culture of the two cell types. Metabolic activity, calcium deposition and alkaline phosphatase activity were assessed over 12 weeks, and reconstructed remodeled biomaterial surfaces were also evaluated for quantitative morphological changes. Increased metabolic activity and increased roughness were found on the clodronate-complexed biomaterial substrates remodeled by osteoblasts and co-cultures of osteoblasts with osteoclasts, even at doses high enough to cause a 90% decrease in osteoclast metabolic activity. Films complexed with low doses of alendronate resulted in increased metabolic activity and calcium deposition by osteoblasts, while higher doses were similarly toxic among osteoclasts, osteoblasts and co-cultures. These results point to the utility of these well-defined bone-mimetic in vitro cultures as useful screens for therapeutics for bone-related diseases, particularly with the ability to conduct studies for extended duration (here for 12 weeks) and with pre-complexed drugs to mimic conditions found in vivo.

Effectiveness of risedronate and alendronate on nonvertebral fractures: an observational study through 2 years of therapy

This observational study showed that after 2 years, both risedronate and alendronate lowered the risk of hip and nonvertebral fractures compared with patients filling in a single bisphosphonate prescription.

INTRODUCTION

Post hoc analyses of the placebo-controlled trials suggested earlier effects for risedronate (6-12 months) than for alendronate (18-24 months). The present study extends our 1-year observational data that confirmed an earlier fracture reduction with risedronate and evaluated the absolute and relative effectiveness of alendronate and risedronate in clinical practice over 2 years.

METHODS

We observed three cohorts of women aged 65 years and older who initiated once-a-week dosing of bisphosphonate therapy; (1) patients adherent to alendronate (n = 21,615), (2) patients adherent to risedronate (n = 12,215), or (3) patients filling only a single bisphosphonate prescription (n = 5,390) as a referent population. Proportional hazard modeling compared the incidence of hip and nonvertebral fractures among the cohorts over 2 years after the initial prescription.

RESULTS

In this cohort, we previously showed at 12 months a significant reduction of hip and nonvertebral fractures with risedronate but not with alendronate. At the end of 2 years, the cumulative incidence of hip fractures in the referent cohort was 1.9 %, and incidence of nonvertebral fractures was 6.3 %. Relative to the referent, 6 months after initiating therapy and continuing through 2 years, both risedronate and alendronate cohorts had approximately a 45 % lower incidence of hip fractures and a 30 % lower incidence of nonvertebral fractures.

CONCLUSION

These observations suggest that both risedronate and alendronate are effective at reducing the risk of hip and nonvertebral fracture after 2 years of treatment and support the post hoc analyses of placebo-controlled trials indicating an earlier effect of risedronate.

An opportunity for improving osteoporosis treatment in home health care

PURPOSE

To examine osteoporosis prevention and treatment among home health care (HHC) patients at risk of fragility fracture in a large, Midwestern integrated HHC system.

METHODS

All patients who received HHC services in 2006 were identified. International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes and pharmaceutical data were examined between January 1, 2004 and December 31, 2005 to determine risk status (high vs average) for fragility fracture. Patients with a documented diagnosis of osteoporosis, osteopenia, previous fragility fracture, stroke, or those taking a glucocorticoid were categorized as high risk. Pharmaceutical data (eg, estrogen, bisphosphonates) were obtained during the same 2-year period to determine treatment status. Descriptive statistics documented the proportion at high risk and treatment status. Inferential statistics tested differences in characteristics (age, gender, race, number of comorbidities) among high-risk patients with and without treatment.

RESULTS

2798 patients were seen in HHC during 2006 and had utilization data available in 2004 and 2005. Of these, 754 were categorized as high risk and 2044 as average risk. Approximately one third (34%) of high-risk patients received osteoporosis medication compared to 4% of average risk (P < .0001). We found no treatment differences based on age. Those with higher comorbidity profiles were less likely to receive treatment (P < .0001).

CONCLUSION

Only 34% of HHC patients at high risk for fracture received adequate treatment. Patients with more comorbidities were least likely to receive treatment. Since these individuals are receiving medical and nursing care, an opportunity exists to increase treatment rates for those at greatest risk.

Risk factors associated with the occurrence of hip fracture in Japanese patients with rheumatoid arthritis: a prospective observational cohort study

Risk factors associated with the occurrence of hip fracture in Japanese patients with rheumatoid arthritis (RA) were evaluated in a prospective, observational cohort study. Physical disability, advanced age, history of total knee replacement (TKR), and low body mass index (BMI) appear to be associated with the occurrence of hip fracture.

INTRODUCTION

This study seeks to evaluate the association between potential risk factors and the occurrence of hip fractures in Japanese RA patients.

METHODS

A total of 9,720 patients (82.1% female; mean age, 55.7 years) with RA were enrolled in a prospective observational study from 2000 to 2010. Self-reported hip fractures were verified using patient medical records. Cox proportional hazards models were used to analyze independent contributions of various risk factors to hip fracture occurrence.

RESULTS

During a mean follow-up of 5.2 years, 152 patients reported 152 hip fractures. Among these patients, 97 hip fractures in 97 patients (15 males, 82 females) were verified with medical records. Japanese version of the Health Assessment Questionnaire (J-HAQ) disability score [per 1 score, hazard ratio (HR), 2.64; 95% confidence interval (CI), 1.94-3.58], age (per 10 years; HR, 1.53; 95% CI, 1.25-1.87), history of TKR (HR, 3.75; 95% CI, 1.57-8.96), and BMI (per 1 kg/m2, HR, 0.92; 95% CI, 0.86-0.99) were significantly associated with hip fractures. Among the scores on the eight domains of the J-HAQ, J-HAQ (arising) (HR, 1.74; 95% CI, 1.28-2.36) and J-HAQ (hygiene) (HR, 1.58; 95% CI, 1.11-2.24) were significantly correlated with the occurrence of hip fracture.

CONCLUSIONS

High J-HAQ disability score, advanced age, history of TKR, and low BMI appear to be associated with the occurrence of hip fractures in Japanese RA patients. Among the eight domains of the J-HAQ, arising and hygiene disabilities appear to be correlated with the occurrence of hip fractures in this patient population.

Biomedical applications of bisphosphonates

Since their discovery over 100 years ago, bisphosphonates have been used industrially as corrosion inhibitors and complexing agents. With the discovery of their pharmacological activity in the late 1960s, implicating their high affinity for hydroxyapatite, bisphosphonates have been employed in the treatment of bone diseases and as targeting agents for colloids and drugs. They have notably been investigated for the treatment of Paget's disease, osteoporosis, bone metastases, malignancy-associated hypercalcemia, and pediatric bone diseases. Currently, they are first-line medications for several of these diseases and are taken by millions of patients worldwide, mostly postmenopausal women. A major problem associated with their use is their low oral bioavailability. Several delivery systems have been proposed to improve their absorption and to direct them to sites other than bone tissues. Beyond their important pharmacological role, the medical applications of bisphosphonates are numerous. In addition, their metal-chelating properties have been exploited to coat and stabilize implants, nanoparticulates, and contrast agents. In this contribution, we review the pharmacological and clinical uses of bisphosphonates and highlight their novel applications in the pharmaceutical and biomedical fields.

Oral bisphosphonates reduce the risk of clinical fractures in glucocorticoid-induced osteoporosis in clinical practice

This study aims to estimate bisphosphonate effectiveness by comparing fracture incidence over time on therapy in glucocorticoid-induced osteoporosis (GIO). From this observational study, alendronate and risedronate decreased clinical vertebral and nonvertebral fractures over time. The effectiveness of each bisphosphonate is consistent with their efficacies demonstrated on surrogate markers in randomized controlled trials (RCTs).

INTRODUCTION

This study aims to estimate bisphosphonate effectiveness by comparing fracture incidence over time on therapy with fracture incidence during a short period after starting a therapy.

METHODS

The study population was a subgroup of a larger cohort study comprising two cohorts of women aged ≥65 years, prescribed with alendronate or risedronate. Within the two study cohorts, 11,007 women were identified as having received glucocorticoids. Within each cohort, the baseline incidence of clinical fractures at nonvertebral and vertebral sites was defined by the initial 3-month period after starting therapy. Relative to these baseline data, we then compared the fracture incidence during the subsequent 12 months on therapy.

RESULTS

The baseline incidence of clinical nonvertebral and vertebral fractures was similar in the alendronate cohort (5.22 and 5.79/100 person-years, respectively) and in the risedronate cohort (5.51 and 5.68/100 person-years, respectively). Relative to the baseline incidence, fracture incidence was significantly lower in the subsequent 12 months in both cohorts of alendronate (33 % lower at nonvertebral sites and 59 % at vertebral sites) and risedronate (28 % lower at nonvertebral sites and 54 % at vertebral sites).

CONCLUSION

From this observational study not designed to compare drugs, both alendronate and risedronate decreased clinical vertebral and nonvertebral fractures over time. The reductions observed in fracture incidence, within each cohort, suggest that the effectiveness of each bisphosphonate in clinical practice is consistent with their efficacies demonstrated on surrogate markers in randomized controlled trials.

Clinical role of bisphosphonate therapy

Bisphosphonates (BPs) are synthetic analogues of pyrophosphate. They inhibit bone resorption and are therefore widely used in disorders where there are increases or disruptions in bone resorption. This includes postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, Paget's disease of bone, and malignancy-related bone loss. To best understand the clinical application of BPs, an understanding of their pharmacokinetics and pharmacodynamics is important. This review describes the structure, pharmacology and mode of action of BPs, focusing on their role in clinical practice. Controversies and side effects surrounding their use will also be discussed.

Time to onset of efficacy in fracture reduction with current anti-osteoporosis treatments

Early prevention of future fracture is an important goal in those at risk. A similar 3-year fracture efficacy is reported for most osteoporosis agents. Onset of fracture efficacy may be useful to help tailor treatment based on risk. We reviewed the peer-reviewed literature for onset of fracture efficacy data on the commonly prescribed osteoporosis treatments. All papers were reviewed independently by at least two reviewers for onset of efficacy for morphometric vertebral fracture (MVF), clinical vertebral fracture (CVF), nonvertebral fracture (NVF), hip fracture, and any clinical fracture (ACF). Alendronate is reported to reduce multiple CVF by 6 months; all CVF, NVF, and multiple ACF by 12 months; and all ACF and hip fracture by 18 months. Ibandronate is reported to reduce MVF by 12 months and NVF by 36 months. Raloxifene is reported to reduce CVF by 3-6 months and NVF by 36 months. Risedronate is reported to reduce CVF and NVF by 6 months, and hip fracture by 12 months. Strontium ranelate is reported to reduce MVF, CVF, NVF, and ACF by 12 months, and hip fracture by 36 months. Zoledronic acid is reported to reduce MVF, CVF, and ACF by 12 months, NVF by 24 months, and hip fracture by 36 months. Although direct comparisons are limited, based on the available literature, risedronate, followed by alendronate, have the earliest onset of benefit across the range of fracture types. Onset of efficacy may be an important consideration in the selection of treatment for some patients.

Secondary causes of osteoporosis in fracture patients

OBJECTIVE

Identification and treatment of osteoporosis in the fragility fracture population and interventions to reduce the risk of future fracture are improving in orthopaedic practice. This study investigated the prevalence of vitamin D insufficiency and deficiency and other secondary causes of low bone density in patients who have sustained a fragility fracture and were referred from fracture clinic to a metabolic bone disease clinic (MBDC) for further assessment.

DESIGN

Retrospective chart audit.

SETTING

University hospital fracture clinic.

PATIENTS

Three hundred ninety-nine patients referred from the orthopaedic division to the MBDC over a 3-year period.

INTERVENTION

A standardized chart audit form was developed, and electronic charts were retrospectively audited.

MAIN OUTCOME MEASUREMENTS

Secondary causes of osteoporosis and routine blood test results.

RESULTS

Three hundred eight of 399 patients had blood investigations completed. A total of 98 patients (32%) had 125 secondary causes of osteoporosis other than vitamin D deficiency or insufficiency recorded in their electronic chart, including medication use, premature ovarian failure, hypogonadism, smoking, excessive alcohol use, renal impairment, gastrointestinal conditions, and endocrine conditions. Mean serum vitamin D level was 69.0 nmol/L in 83 men and 75.4 nmol/L in 186 women. Serum vitamin D levels were deficient at ≤25 nmol/L in 7 patients, insufficient at 26-74 nmol/L in 137 patients, and sufficient at ≥75 nmol/L in 125 patients. Investigation of causes of secondary osteoporosis can inform and influence specific treatment regimens.

CONCLUSIONS

More than one-half of patients sustaining a fragility fracture and referred to the MBDC were vitamin D insufficient or deficient, and nearly one-third had a secondary cause of osteoporosis other than vitamin D insufficiency/deficiency. A standardized list of blood and urine analyses and radiographs has been implemented for fragility fracture patients and selected other fracture patients who are undergoing investigation for osteoporosis.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Bazedoxifene: the evolving role of third-generation selective estrogen-receptor modulators in the management of postmenopausal osteoporosis

Osteoporosis is a significant public health concern, particularly for postmenopausal women. Current treatment options may not be appropriate for all women. Selective estrogen-receptor modulators (SERMs) are a class of molecules with tissue-selective activity. Bazedoxifene is currently in clinical development for the prevention and treatment of postmenopausal osteoporosis. In a 2-year, phase III, osteoporosis prevention study (N = 1583), bazedoxifene 10, 20, and 40 mg was shown to preserve bone mineral density and decrease biochemical markers of bone turnover compared with placebo in postmenopausal women at risk for osteoporosis. In a pivotal 3-year, phase III, osteoporosis treatment study (N = 7492), bazedoxifene 20 and 40 mg significantly reduced the incidence of new vertebral fractures compared with placebo (p < 0.05 for both) in postmenopausal women with osteoporosis. In a post hoc subgroup analysis of women at higher risk for fracture (n = 1772), bazedoxifene 20 mg significantly reduced the risk of nonvertebral fractures versus placebo (p = 0.02) and raloxifene 60 mg (p = 0.05). Bazedoxifene 20 mg has demonstrated sustained efficacy in reducing the risk of vertebral fractures over 5 and 7 years. Overall, bazedoxifene was generally safe and well tolerated, with favorable endometrial and breast safety profiles. As with other SERMs, the rate of deep vein thrombosis was higher in the bazedoxifene groups compared with placebo at 3 and 5 years. Considering its demonstrated efficacy and safety, bazedoxifene may be an appropriate osteoporosis therapy for women who cannot take or are unwilling to take bisphosphonates because of safety or tolerability issues. Bazedoxifene may also be appropriate for younger women at increased fracture risk who are concerned about the effects of long-term bisphosphonate therapy. This article reviews the results of key clinical trials of bazedoxifene for the prevention and treatment of postmenopausal osteoporosis and describes its role in clinical practice.

Evidence of sustained vertebral and nonvertebral antifracture efficacy with ibandronate therapy: a systematic review

BACKGROUND

The antifracture efficacy of ibandronate at vertebral and nonvertebral sites was assessed.

METHODS

A literature review of randomized phase III clinical trials, meta-analyses or observational studies that reported fracture endpoints or surrogate markers, and compared ibandronate with placebo or an active comparator.

RESULTS

In a phase III study, 2.5 mg daily oral ibandronate reduced the incidence of new vertebral fractures versus placebo and the relative risk reduction (RRR) was sustained over 3 years (62%; p = 0.0001). In two bridging studies, oral ibandronate 150 mg once monthly and 3 mg quarterly intravenous (i.v.) were superior to oral 2.5 mg daily in producing bone mineral density (BMD) increases at all sites over 2 years (p < 0.05). These improvements were sustained over 5 years. In meta-analyses of pivotal ibandronate studies, doses equivalent to annual cumulative exposure (ACE) ≥ 10.8 mg (including 150 mg once monthly and 3 mg quarterly i.v.) significantly reduced the incidence of nonvertebral fractures versus placebo or ACE 5.5 mg (2.5 mg daily) (RRR 29.9% and 38%, respectively; p < 0.05). Therefore, prevention of nonvertebral fractures was found in all patients with the commercially available highest doses, and not only in high-risk patients as observed in randomized clinical trials with lower doses. Finally, a 12-month, observational study of claims databases reported comparable rates of nonvertebral fractures and a statistically significantly lower rate of vertebral fractures (p < 0.01) with ibandronate versus weekly bisphosphonates.

CONCLUSION

A large body of evidence suggests that ibandronate has sustained vertebral and nonvertebral antifracture efficacy in women with postmenopausal osteoporosis.

Regional bone metabolism at the lumbar spine and hip following discontinuation of alendronate and risedronate treatment in postmenopausal women

The aim of this study was to examine the effects of bisphosphonate discontinuation on bone metabolism at the spine and hip measured using (18) F-fluoride PET. Bone metabolism at the spine remained stable following discontinuation of alendronate and risedronate at 1 year but increased in the hip in the alendronate group only.

INTRODUCTION

Bisphosphonates such as alendronate (ALN) or risedronate (RIS) have persistent effects on spine BMD following discontinuation.

METHODS

Positron emission tomography (PET) was used to examine regional bone metabolism in 20 postmenopausal women treated with ALN (n = 11) or RIS (n = 9) for a minimum of 3 years at screening (range 3-9 years, mean 5 years for both groups). Subjects underwent a dynamic scan of the lumbar spine and a static scan of both hips at baseline and 6 and 12 months following treatment discontinuation. (18) F-fluoride plasma clearance (K(i)) at the spine was calculated using a three-compartment model. Standardised uptake values (SUV) were calculated for the spine, total hip, femoral neck and femoral shaft. Measurements of BMD and biochemical markers of bone turnover were also performed.

RESULTS

With the exception of a significant decrease in spine BMD in the ALN group, BMD remained stable. Bone turnover markers increased significantly from baseline by 12 months for both study groups. Measurements of K(i) and SUV at the spine and femoral neck did not change significantly in either group. SUV at the femoral shaft and total hip increased significantly but in the ALN group only, increasing by 33.8% (p = 0.028) and 24.0% (p = 0.013), respectively.

CONCLUSIONS

Bone metabolism at the spine remained suppressed following treatment discontinuation. A significant increase in SUV at the femoral shaft and total hip after 12 months was observed but for the ALN group only. This study was small, and further clinical studies are required to fully evaluate the persistence of BP treatment.

Individualizing osteoporosis therapy

Guidelines for osteoporosis treatment are available; however, these guidelines suggest when to treat patients, without specific recommendations on what drugs to prescribe in various situations. Choice of osteoporosis therapy should be individualized based on consideration of the efficacy, safety, cost, convenience (i.e., dosing regimen and delivery), and other non-osteoporosis-related benefits associated with each agent. Bisphosphonates, administered orally or intravenously, should be considered first-line therapy, particularly in older patients, owing to their efficacy across multiple skeletal sites; however, there are potential short- and long-term safety concerns. Selective estrogen receptor modulators should be considered for younger postmenopausal women at greater risk for vertebral than hip fractures or as second-line therapy in women who cannot tolerate first-line therapies. Low-dose hormone therapy may be appropriate as prevention in women with menopausal symptoms at lower fracture risk. Calcitonin, with its relatively benign safety profile, may be appropriate for elderly women who may have difficulty following the complex dosing schedules of oral bisphosphonates. Anabolic therapies such as teriparatide should be considered for high-risk patients. Strontium ranelate (approved outside of North America), with both anabolic and antiresorptive properties, may be appropriate for women who cannot tolerate or are unable to take bisphosphonates. Denosumab is a monoclonal antibody appropriate for women at high fracture risk or who have failed other osteoporosis therapies, and may be considered in patients with renal insufficiency. It will be important to incorporate newer agents (e.g., bazedoxifene, tissue selective estrogen complex) into this individualized treatment paradigm to optimize clinical outcomes in patients with osteoporosis.

Bisphosphonate binding affinity affects drug distribution in both intracortical and trabecular bone of rabbits

Differences in the binding affinities of bisphosphonates for bone mineral have been proposed to determine their localizations and duration of action within bone. The main objective of this study was to test the hypothesis that mineral binding affinity affects bisphosphonate distribution at the basic multicellular unit (BMU) level within both cortical and cancellous bone. To accomplish this objective, skeletally mature female rabbits (n = 8) were injected simultaneously with both low- and high-affinity bisphosphonate analogs bound to different fluorophores. Skeletal distribution was assessed in the rib, tibia, and vertebra using confocal microscopy. The staining intensity ratio between osteocytes contained within the cement line of newly formed rib osteons or within the reversal line of hemiosteons in vertebral trabeculae compared to osteocytes outside the cement/reversal line was greater for the high-affinity compared to the low-affinity compound. This indicates that the low-affinity compound distributes more equally across the cement/reversal line compared to a high-affinity compound, which concentrates mostly near surfaces. These data, from an animal model that undergoes intracortical remodeling similar to humans, demonstrate that the affinity of bisphosphonates for the bone determines the reach of the drugs in both cortical and cancellous bone.

Osteoporosis, frailty and fracture: implications for case finding and therapy

In almost all patients with incident fractures, the absolute risk of subsequent fracture and mortality is highest immediately after the fracture is incurred; the risk is substantially increased in frail elderly patients. The risk factors for incident fractures, such as bone fragility, tendency to fall and the presence of metabolic bone disease, remain underdiagnosed and undertreated. Here, we review the evidence that demonstrates the influence of these risk factors on susceptibility to subsequent fracture and mortality after an incident fracture, and discuss the tools available to predict these outcomes. In this Review, we also propose a systematic, coordinator-based approach to assessment of risk, allocation of treatment and follow-up in all patients over 50 years of age who present with a fracture. The aim of this proposed multistep procedure is to improve the prevention of secondary fracture, decrease mortality rates and reduce patient undertreatment or overtreatment.

Risedronate's Role in Reducing Hip Fracture in Postmenopausal Women with Established Osteoporosis

Osteoporosis is a significant concern for postmenopausal women and is a critical factor in hip fracture. Examining evidence for osteoporosis medications in hip fracture is important for optimizing treatment.

PURPOSE

Review risedronate's role for hip fracture in postmenopausal women.

METHODS

A literature search was conducted using Medline and Web of Science. The search was limited using the terms "risedronate" and "hip fracture," and to studies that included women. Similar articles linked to the search and pertinent articles in bibliographies were also examined.

RESULTS

Risedronate has demonstrated efficacy and cost effectiveness for hip fracture, but may not be beneficial for patients with low fracture risk. Risedronate is generally well tolerated, but may cause side effects in some patient populations.

CONCLUSION

Risedronate has benefit for hip fracture, but patients should be carefully screened to determine the appropriateness of risedronate before starting treatment.

Contralateral hip fractures and other osteoporosis-related fractures in hip fracture patients: incidence and risk factors. An observational cohort study of 1,229 patients

PURPOSE

To report risk factors, 1-year and overall risk for a contralateral hip and other osteoporosis-related fractures in a hip fracture population.

METHODS

An observational study on 1,229 consecutive patients of 50 years and older, who sustained a hip fracture between January 2005 and June 2009. Fractures were scored retrospectively for 2005-2008 and prospectively for 2008-2009. Rates of a contralateral hip and other osteoporosis-related fractures were compared between patients with and without a history of a fracture. Previous fractures, gender, age and ASA classification were analysed as possible risk factors.

RESULTS

The absolute risk for a contralateral hip fracture was 13.8 %, for one or more osteoporosis-related fracture(s) 28.6 %. First-, second- and third-year risk for a second hip fracture was 2, 1 and 0 %. Median (IQR) interval between both hip fractures was 18.5 (26.6) months. One-year incidence of other fractures was 6 %. Only age was a risk factor for a contralateral hip fracture, hazard ratio (HR) 1.02 (1.006-1.042, p = 0.008). Patients with a history of a fracture (33.1 %) did not have a higher incidence of fractures during follow-up (16.7 %) than patients without fractures in their history (14 %). HR for a contralateral hip fracture for the fracture versus the non-fracture group was 1.29 (0.75-2.23, p = 0.360).

CONCLUSION

The absolute risk of a contralateral hip fracture after a hip fracture is 13.8 %, the 1-year risk was 2 %, with a short interval between the 2 hip fractures. Age was a risk factor for sustaining a contralateral hip fracture; a fracture in history was not.

Validation of diagnostic codes for subtrochanteric, diaphyseal, and atypical femoral fractures using administrative claims data

Administrative claims databases have large samples and high generalizability. They have been used to evaluate associations of atypical femoral fractures with bisphosphonates. We developed and assessed accuracy of claims-based algorithms with hospital and physician diagnosis codes for these fractures. Medical records and radiology reports of all adults admitted at University of Alabama at Birmingham Health System from 2004 to 2008 with International Classification of Diseases, Ninth Revision hospital discharges and surgeons' fracture repair codes for subtrochanteric femoral fractures and random sample of other femoral fractures were reviewed. We identified 137 persons with suspected subtrochanteric femoral fractures and randomly selected 50 persons with either suspected diaphyseal femoral fractures or hip fractures other than subtrochanteric and diaphyseal femoral fractures (typical hip fractures). Eleven patients had radiographic features indicative of atypical femoral fractures. The positive predictive value (PPV) of claims-based algorithms varied with primary or secondary positions on discharge diagnoses and the sources of diagnosis codes. The PPV for fractures ranged 69-89% for subtrochanteric femoral, 89-98% for diaphyseal femoral, and 85-98% for typical hip fractures. The PPV of administrative codes for defining a femoral fracture as atypical was low and imprecise. Claims-based algorithms combining hospital discharges with surgeon's diagnosis codes had high PPV to identify the site of subtrochanteric or diaphyseal femoral fractures vs typical hip fractures. However, claims-based data were not accurate in identifying atypical femoral fractures. These claims algorithms will be useful in future population-based observational studies to evaluate associations between osteoporosis medications and subtrochanteric and diaphyseal femoral fractures.

Bisphosphonate therapy for osteoporosis: combining optimal fracture risk reduction with patient preference

OBJECTIVE

To review current use of bisphosphonates as first-line therapy for osteoporosis, with an emphasis on the importance of patient compliance and persistence.

METHODS

The US National Library of Medicine was used to obtain the relevant information on current bisphosphonate treatment for osteoporosis management, and patient compliance and persistence with treatment.

RESULTS

Bisphosphonates have demonstrated efficacy in fracture risk reduction, although differences may exist with respect to both onset of action and the site of fracture risk reduction. Good compliance and persistence with osteoporosis therapy is needed to reduce fracture risk, but currently the willingness of patients to conform to their prescribed course of treatment is suboptimal. Intermittent dosing schedules have been developed to facilitate ease of medication-taking in order to help improve rates of compliance and persistence. When primary care physicians provide patients with information about the established efficacy and safety of medications, as well as clarifying the crucial link between continued, consistent treatment and fracture risk reduction, patients are more likely to understand the importance of taking their medications consistently in order to maximize the effectiveness of the therapy.

CONCLUSIONS

A therapy that provides vertebral and nonvertebral efficacy, is well-tolerated, and offers a flexible dosing regimen is likely to enhance patient compliance and persistence, and provide optimal fracture protection. Numerous studies have consistently demonstrated that medication compliance and persistence are well-correlated with fracture risk reduction.

Longitudinal change in hip fracture incidence after starting risedronate or raloxifene: an observational study

This study examined patients' risk profiles and adherence to treatment in relation to the effect of risedronate and raloxifene on hip fracture incidence. Administrative billing data were used to follow two cohorts of women aged 65 and older after starting therapy with either risedronate (n = 86,735) or raloxifene (n = 37,726). The fracture risk profile was described using a 6-month history period before starting therapy. Effectiveness of each therapy was evaluated by comparing the incidence of hip fractures during the first 3 months with the subsequent 12 months among women adherent (medication possession ratio >80%) compared with those non-adherent to treatment. At the start of therapy, the raloxifene cohort was younger than the risedronate cohort (median age 73 vs. 76 years) and had fewer prior fractures (p < 0.01 for both). In the first 3 months of therapy, hip fracture incidence was lower in the raloxifene group (0.51 per 100 person-years) compared with the risedronate group (0.94 per 100 person-years). In the subsequent 12 months, the incidence of hip fractures decreased among patients adherent to the risedronate regimen [relative risk (RR) 0.70, 95% CI 0.59-0.84, p < 0.01] and did not change significantly among patients adherent to the raloxifene regimen (RR 1.02, 95% CI 0.73-1.44). In poorly adherent patients, neither drug decreased hip fracture risk. Risedronate treatment in adherent patients rapidly decreased the risk of hip fractures, whereas raloxifene treatment did not.

Differences in persistence, safety and efficacy of generic and original branded once weekly bisphosphonates in patients with postmenopausal osteoporosis: 1-year results of a retrospective patient chart review analysis

The objective of this study was to compare the changes on bone mineral density, and the effects on persistence and adverse events in patients treated for postmenopausal osteoporosis with generic alendronate or with branded alendronate (Fosamax®) or branded risedronate (Actonel®) once weekly. In this retrospective patient chart analysis, we reviewed the 1-year observational treatment results for 186 women (ITT population) with postmenopausal osteoporosis. Patients from our outpatient department, who had started with once-weekly bisphosphonate therapy between 36 and at least 12 months before this chart review, were included in this comparative three-arm study according to their treatment: A, Generic Alendonate 70 mg products; B, Branded Alendronate (Fosamax®) 70 mg once weekly and C, Branded Risedronate (Actonel®) 35 mg once weekly. All patients received basic therapy with 1,200 mg calcium and 800 IU vitamin D per day. Patient’s bone mineral density (BMD) at lumbar spine and total hip was below −2.5 T-score, and they were with or without prevalent vertebral and non-vertebral fractures. Data analysis regarding the 186 patients shows an average increase in LS-BMD after 12 months of 2.8, 5.2 and 4.8% for the groups A, B and C, respectively. The respective mean changes at total hip were 1.5, 2.9, and 3.1%. At both sites, the mean increases in BMD were not different between the two groups receiving branded bisphosphonates (B, C) but for both were significantly higher than for the group treated with generic alendronate (A). At 12 months, 68% of group A, 84% of group B and 94% of group C were still on bisphosphonate therapy. The persistence of patients treated with generic alendronate was significantly lower as compared to each of the two with branded bisphosphonate-treated groups. The total numbers of patients reporting gastrointestinal adverse events were 32, 15 and 9 for group A, group B, and group C, respectively. Significantly lower increases of lumbar spine and total hip BMD with generic alendronate once weekly as compared to the two branded bisphosphonate originals (Fosamax®, Actonel®) were observed. The reasons for the 40–50% lower BMD increase rates when using the generic compounds are not known yet. At least in part the lower efficacy can be explained by a significantly lower degree of persistence with generic alendronate, which could be related to a higher incidence of gastrointestinal adverse events. Other reasons could be lower bioavailability or potency of generic alendronate.

Greater magnitude of turnover suppression occurs earlier after treatment initiation with risedronate than alendronate

Clinical data suggest that reductions in fractures associated with osteoporosis may occur sooner in patients treated with risedronate (RIS) compared to those treated with alendronate (ALN). This could be explained by differences in the time course of turnover suppression between these two bisphosphonates. To determine if differences in the onset of turnover suppression exist between RIS and ALN, female New Zealand white rabbits (total n=32) were treated with clinically relevant doses of RIS or ALN and then administered different fluorochrome labels weekly for four weeks in order to allow histological assessment of the time-course of turnover suppression. By the third week of treatment vertebral trabecular bone formation rate (BFR/BS) was significantly suppressed with RIS-treatment compared to both VEH and ALN. By the 4th week of treatment, turnover rates in RIS-treated animals remained significantly lower than in VEH-treated animals and were also lower than ALN; at this time-point ALN was significantly lower than VEH. There was no significant reduction in intra-cortical remodeling in the tibial mid-diaphysis at any time point for either RIS or ALN. This greater effect on turnover suppression with RIS early in treatment compared to ALN is likely the result of both risedronate's greater potency on osteoclast inhibition and its lower binding affinity. Together with studies showing more rapid return toward baseline turnover following withdrawal of RIS compared to ALN, this pre-clinical study provides evidence of the differences between bisphosphonates with respect to onset and recovery of bone turnover suppression.

Coordinator-based systems for secondary prevention in fragility fracture patients

The underlying causes of incident fractures--bone fragility and the tendency to fall--remain under-diagnosed and under-treated. This care gap in secondary prevention must be addressed to minimise both the debilitating consequences of subsequent fractures for patients and the associated economic burden to healthcare systems. Clinical systems aimed at ensuring appropriate management of patients following fracture have been developed around the world. A systematic review of the literature showed that 65% of systems reported include a dedicated coordinator who acts as the link between the orthopaedic team, the osteoporosis and falls services, the patient and the primary care physician. Coordinator-based systems facilitate bone mineral density testing, osteoporosis education and care in patients following a fragility fracture and have been shown to be cost-saving. Other success factors included a fracture registry and a database to monitor the care provided to the fracture patient. Implementation of such a system requires an audit of existing arrangements, creation of a network of healthcare professionals with clearly defined roles and the identification of a 'medical champion' to lead the project. A business case is needed to acquire the necessary funding. Incremental, achievable targets should be identified. Clinical pathways should be supported by evidence-based recommendations from national or regional guidelines. Endorsement of the proposed model within national healthcare policies and advocacy programmes can achieve alignment of the objectives of policy makers, professionals and patients. Successful transformation of care relies upon consensus amongst all participants in the multi-disciplinary team that cares for fragility fracture patients.

Bisphosphonate effects on bone turnover, microdamage, and mechanical properties: what we think we know and what we know that we don't know

The bisphosphonates (BPs) have been useful tools in our understanding of the role that bone remodeling plays in skeletal health. The purpose of this paper is to outline what we know, and what is still unknown, about the role that BPs play in modulating bone turnover, how this affects microdamage accumulation, and ultimately what the effects of these changes elicited by BPs are to the structural and the material biomechanical properties of the skeleton. We know that BPs suppress remodeling site-specifically, probably do not have a direct effect on formation, and that the individual BPs vary with respect to speed of onset, duration of effect and magnitude of suppression. However, we do not know if these differences are meaningful in a clinical sense, how much remodeling is sufficient, the optimal duration of treatment, or how long it takes to restore remodeling to pre-treatment levels following withdrawal. We also know that suppression is intimately tied to microdamage accumulation, which is also site-specific, that BPs impair targeted repair of damage, and that they can reduce the energy absorption capacity of bone at the tissue level. However, the BPs are clearly effective at preventing fracture, and generally increase bone mineral density and whole bone strength, so we do not know whether these changes in damage accumulation and repair, or the mechanical effects at the tissue level, are clinically meaningful. The mechanical effects of BPs on the fatigue life of bone, or BP effects on bone subject to an impact, are entirely unknown. This paper reviews the literature on these topics, and identifies gaps in knowledge that can be addressed with further research.

Bisphosphonates for post-menopausal osteoporosis: are they all the same?

The primary goal of treatment for post-menopausal osteoporosis (PMO) is reduction in fracture risk. Therefore, clinicians must recommend therapies that are safe and have proven anti-fracture efficacy. Bisphosphonates have long been established as first-line therapy for osteoporosis and several of these drugs significantly reduce osteoporotic fracture risk. However, choosing among different bisphosphonates can represent a difficult clinical decision. This review outlines the pharmacology of various bisphosphonates, discusses how their pharmacological characteristics affect their efficacy, and summarizes clinical safety and efficacy data. Clinical trial data and the opinions of expert bodies suggest that alendronate, risedronate, ibandronate and zoledronic acid all provide fracture protection for patients with PMO. However, there are differences among these agents. For example, all four agents have demonstrated efficacy in preventing vertebral fractures, but only zoledronic acid and risedronate significantly reduce non-vertebral fracture risk in pivotal trials. Moreover, reduction in hip fracture risk has only been established for alendronate, risedronate and zoledronic acid. Current data suggest that ibandronate and zoledronic acid have the most persistent antifracture effect. Bisphosphonates have been associated with a number of side effects, the evidence for which is summarized in this review. The most pertinent of these when choosing a bisphosphonate for a particular patient are the well-documented associations between gastrointestinal adverse events and oral administration, and between acute phase reactions and intravenous administration. Ultimately, selection of a specific bisphosphonate for treatment of PMO should be based on efficacy, risk profile, cost-effectiveness and patient preference.

Bisphosphonates in phenytoin-induced bone disorder

Chronic administration of phenytoin (PHT) has been associated with bone loss. Bisphosphonates [alendronate (ALD), ibandronate (IBD) and risedronate (RSD)] are potential candidates to prevent PHT-induced bone disorders, and the present study evaluated their effect on the antiepileptic efficacy of PHT. The PHT-induced depletion in folic acid (FA), vitamin B6 and vitamin B12 results in hyperhomocysteinemia. The elevated circulating homocysteine (hcy) could be a risk indicator for micronutrient-deficiency-related osteoporosis via generation of free radicals. Thus, an attempt was also made to unravel the PHT's and bisphosphonates' effect on hcy. Male mice received PHT (35 mg/kg, p.o.) for 90 days to induce bone loss. ALD, RSD and IBD were administered orally at doses 0.65 mg/kg, 0.33 mg/kg, and 0.17 mg/kg respectively, for prevention and 1.3mg/kg, 0.65 mg/kg, and 0.33 mg/kg respectively, for treatment of PHT-induced bone loss. The bone loss was confirmed by bone mineral density (BMD) analysis and bone turnover markers. Serum levels of hcy and FA were estimated along with hydrogen peroxide levels and total antioxidant capacity in order to assess the antioxidant profile of bisphosphonates. The induction of bone loss by PHT was marked by lowered BMD and altered bone turnovers. ALD and RSD administration to PHT treated groups significantly reverted the bony adverse effects. No such effects were observed with IBD. In the bisphosphonates treated groups, hcy levels were statistically at par with the control group. PHT at 35 mg/kg, p.o. could compromise bone mass and thus, could be a model of bone demineralization in mice. The ALD, IBD and RSD have no pharmacodynamic interaction when administered along with PHT at the experimental level. Thus, their usage in the management of PHT-induced bone disease could be worthwhile if clinically approved.