Effect of intermittent cyclical etidronate therapy on bone mass and fracture rate in women with postmenopausal osteoporosis

Etidronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women

BACKGROUND

Osteoporosis is an abnormal reduction in bone mass and bone deterioration, leading to increased fracture risk. Etidronate belongs to the bisphosphonate class of drugs which act to inhibit bone resorption by interfering with the activity of osteoclasts - bone cells that break down bone tissue. This is an update of a Cochrane review first published in 2008. For clinical relevance, we investigated etidronate's effects on postmenopausal women stratified by fracture risk (low versus high).

OBJECTIVES

To assess the benefits and harms of intermittent/cyclic etidronate in the primary and secondary prevention of osteoporotic fractures in postmenopausal women at lower and higher risk of fracture, respectively.

SEARCH METHODS

We searched the Cochrane Central Register of Control Trials (CENTRAL), MEDLINE, Embase, two clinical trial registers, the websites of drug approval agencies, and the bibliographies of relevant systematic reviews. We identified eligible trials published between 1966 and February 2023.

SELECTION CRITERIA

We included randomized controlled trials that assessed the benefits and harms of etidronate in the prevention of fractures for postmenopausal women. Women in the experimental arms must have received at least one year of etidronate, with or without other anti-osteoporotic drugs and concurrent calcium/vitamin D. Eligible comparators were placebo (i.e. no treatment; or calcium, vitamin D, or both) or another anti-osteoporotic drug. Major outcomes were clinical vertebral, non-vertebral, hip, and wrist fractures, withdrawals due to adverse events, and serious adverse events. We classified a study as secondary prevention if its population fulfilled one or more of the following hierarchical criteria: a diagnosis of osteoporosis, a history of vertebral fractures, a low bone mineral density T-score (≤ -2.5), or aged 75 years or older. If none of these criteria were met, we considered the study to be primary prevention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The review has three main comparisons: (1) etidronate 400 mg/day versus placebo; (2) etidronate 200 mg/day versus placebo; (3) etidronate at any dosage versus another anti-osteoporotic agent. We stratified the analyses for each comparison into primary and secondary prevention studies. For major outcomes in the placebo-controlled studies of etidronate 400 mg/day, we followed our original review by defining a greater than 15% relative change as clinically important. For all outcomes of interest, we extracted outcome measurements at the longest time point in the study.

MAIN RESULTS

Thirty studies met the review's eligibility criteria. Of these, 26 studies, with a total of 2770 women, reported data that we could extract and quantitatively synthesize. There were nine primary and 17 secondary prevention studies. We had concerns about at least one risk of bias domain in each study. None of the studies described appropriate methods for allocation concealment, although 27% described adequate methods of random sequence generation. We judged that only 8% of the studies avoided performance bias, and provided adequate descriptions of appropriate blinding methods. One-quarter of studies that reported efficacy outcomes were at high risk of attrition bias, whilst 23% of studies reporting safety outcomes were at high risk in this domain. The 30 included studies compared (1) etidronate 400 mg/day to placebo (13 studies: nine primary and four secondary prevention); (2) etidronate 200 mg/day to placebo (three studies, all secondary prevention); or (3) etidronate (both dosing regimens) to another anti-osteoporotic agent (14 studies: one primary and 13 secondary prevention). We discuss only the etidronate 400 mg/day versus placebo comparison here. For primary prevention, we collected moderate- to very low-certainty evidence from nine studies (one to four years in length) including 740 postmenopausal women at lower risk of fractures. Compared to placebo, etidronate 400 mg/day probably results in little to no difference in non-vertebral fractures (risk ratio (RR) 0.56, 95% confidence interval (CI) 0.20 to 1.61); absolute risk reduction (ARR) 4.8% fewer, 95% CI 8.9% fewer to 6.1% more) and serious adverse events (RR 0.90, 95% CI 0.52 to 1.54; ARR 1.1% fewer, 95% CI 4.9% fewer to 5.3% more), based on moderate-certainty evidence. Etidronate 400 mg/day may result in little to no difference in clinical vertebral fractures (RR 3.03, 95% CI 0.32 to 28.44; ARR 0.02% more, 95% CI 0% fewer to 0% more) and withdrawals due to adverse events (RR 1.41, 95% CI 0.81 to 2.47; ARR 2.3% more, 95% CI 1.1% fewer to 8.4% more), based on low-certainty evidence. We do not know the effect of etidronate on hip fractures because the evidence is very uncertain (RR not estimable based on very low-certainty evidence). Wrist fractures were not reported in the included studies. For secondary prevention, four studies (two to four years in length) including 667 postmenopausal women at higher risk of fractures provided the evidence. Compared to placebo, etidronate 400 mg/day may make little or no difference to non-vertebral fractures (RR 1.07, 95% CI 0.72 to 1.58; ARR 0.9% more, 95% CI 3.8% fewer to 8.1% more), based on low-certainty evidence. The evidence is very uncertain about etidronate's effects on hip fractures (RR 0.93, 95% CI 0.17 to 5.19; ARR 0.0% fewer, 95% CI 1.2% fewer to 6.3% more), wrist fractures (RR 0.90, 95% CI 0.13 to 6.04; ARR 0.0% fewer, 95% CI 2.5% fewer to 15.9% more), withdrawals due to adverse events (RR 1.09, 95% CI 0.54 to 2.18; ARR 0.4% more, 95% CI 1.9% fewer to 4.9% more), and serious adverse events (RR not estimable), compared to placebo. Clinical vertebral fractures were not reported in the included studies.

AUTHORS' CONCLUSIONS

This update echoes the key findings of our previous review that etidronate probably makes or may make little to no difference to vertebral and non-vertebral fractures for both primary and secondary prevention.

Refracture following vertebral fragility fracture when bone fragility is not recognized: summarizing findings from comparator arms of randomized clinical trials

PURPOSE

Since vertebral fragility fractures (VFFs) might increase the risk of subsequent fractures, we evaluated the incidence rate and the refracture risk of subsequent vertebral and non-vertebral fragility fractures (nVFFs) in untreated patients with a previous VFF.

METHODS

We systematically searched PubMed, Embase, and Cochrane Library up to February 2022 for randomized clinical trials (RCTs) that analyzed the occurrence of subsequent fractures in untreated patients with prior VFFs. Two authors independently extracted data and appraised the risk of bias in the selected studies. Primary outcomes were subsequent VFFs, while secondary outcomes were further nVFFs. The outcome of refracture within ≥ 2 years after the index fracture was measured as (i) rate, expressed per 100 person-years (PYs), and (ii) risk, expressed in percentage.

RESULTS

Forty RCTs met our inclusion criteria, ranging from medium to high quality. Among untreated patients with prior VFFs, the rate of subsequent VFFs and nVFFs was 12 [95% confidence interval (CI) 9-16] and 6 (95% CI 5-8%) per 100 PYs, respectively. The higher the number of previous VFFs, the higher the incidence. Moreover, the risk of VFFs and nVFFs increased within 2 (16.6% and 8%) and 4 years (35.1% and 17.4%) based on the index VFF.

CONCLUSION

The highest risk of subsequent VFFs or nVFFs was already detected within 2 years following the initial VFF. Thus, prompt interventions should be designed to improve the detection and treatment of VFFs, aiming to reduce the risk of future FFs and properly implement secondary preventive measures.

Sequential management of postmenopausal health and osteoporosis: An update

Increased life expectancy means that women are now in a hypoestrogenic state for approximately one-third of their lives. Overall health and specifically bone health during this period evolves in accordance with aging and successive exposure to various risk factors. In this review, we provide a summary of the approaches to the sequential management of osteoporosis within an integrative model of care to offer physicians a useful tool to facilitate therapeutic decision-making. Current evidence suggests that pharmacologic agents should be selected based on the risk of fractures, which does not always correlate with age. Due to their effect on bone turnover and on other hormone-regulated phenomena, such as hot flushes or breast cancer risk, we position hormone therapy and selective estrogen receptor modulators as an early postmenopause intervention for the management of postmenopausal osteoporosis. When the use of these agents is not possible, compelling evidence supports antiresorptive agents as first-line treatment of postmenopausal osteoporosis in many clinical scenarios, with digestive conditions, kidney function, readiness for compliance, or patient preferences playing a role in choosing between bisphosphonates or denosumab during this period. For patients at high risk of osteoporotic fracture, the "anabolic first" approach reduces that risk. The effect on bone health with these bone-forming agents or with denosumab should be consolidated with the subsequent use of antiresorptive agents. Regardless of the strategy, follow-up and treatment should be maintained indefinitely to help prevent fractures.

Pharmaceutical treatment of bone loss: From animal models and drug development to future treatment strategies

Animal models are fundamental to advance our knowledge of the underlying pathophysiology of bone loss and to study pharmaceutical countermeasures against it. The animal model of post-menopausal osteoporosis from ovariectomy is the most widely used preclinical approach to study skeletal deterioration. However, several other animal models exist, each with unique characteristics such as bone loss from disuse, lactation, glucocorticoid excess, or exposure to hypobaric hypoxia. The present review aimed to provide a comprehensive overview of these animal models to emphasize the importance and significance of investigating bone loss and pharmaceutical countermeasures from perspectives other than post-menopausal osteoporosis only. Hence, the pathophysiology and underlying cellular mechanisms involved in the various types of bone loss are different, and this might influence which prevention and treatment strategies are the most effective. In addition, the review sought to map the current landscape of pharmaceutical countermeasures against osteoporosis with an emphasis on how drug development has changed from being driven by clinical observations and enhancement or repurposing of existing drugs to today's use of targeted anti-bodies that are the result of advanced insights into the underlying molecular mechanisms of bone formation and resorption. Moreover, new treatment combinations or repurposing opportunities of already approved drugs with a focus on dabigatran, parathyroid hormone and abaloparatide, growth hormone, inhibitors of the activin signaling pathway, acetazolamide, zoledronate, and romosozumab are discussed. Despite the considerable progress in drug development, there is still a clear need to improve treatment strategies and develop new pharmaceuticals against various types of osteoporosis. The review also highlights that new treatment indications should be explored using multiple animal models of bone loss in order to ensure a broad representation of different types of skeletal deterioration instead of mainly focusing on primary osteoporosis from post-menopausal estrogen deficiency.

Novel formulations of oral bisphosphonates in the treatment of osteoporosis

Oral bisphosphonates are a key intervention in the treatment of osteoporosis and in reducing the risk of fragility fractures. Their use is supported by over 3 decades of evidence; however, patient adherence to oral bisphosphonates remains poor in part due to complex dosing instructions and adverse events, including upper gastrointestinal symptoms. This problem has led to the development of novel oral bisphosphonate formulations. Buffered, effervescent alendronate is dissolved in water and so seeks to reduce upper gastro-intestinal adverse events, and gastro-resistant risedronate aims to reduce the complexity of dosing procedure (e.g. fasting prior to consumption) whilst still maintaining the efficacy of fracture risk reduction. Clinical trials and real-world data have been employed to demonstrate some benefits in terms of reduced upper gastro-intestinal adverse events, adherence, persistence and health economic outcomes. This report describes the result of an ESCEO (European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis) expert working group, which explores where oral bisphosphonates sit in current clinical practice guidelines, review their risk-benefit profile and the consequences of poor adherence before exploring novel oral bisphosphonate formulations and their potential clinical and health economic impact. Further research is required but there are signs that these novel, oral bisphosphonate formulations may lead to improved tolerance of oral bisphosphonates and thus, improved adherence and fracture outcomes.

Detection and residence time of bisphosphonates in bone of horses

Bisphosphonates are potent anti-resorptive agents that have the potential to adversely affect bone healing in equine athletes, and normal bone adaption in young racehorses. A concern exists that bisphosphonate inhibition of normal bone metabolism could lead to increased bone fractures during high-intensity exercise. We found only a single report describing concentrations of tiludronate in the bone of horses, and no studies describing clodronate. Knowledge of the residence time in bone could allow for a better understanding of the long-term effects of these compounds. Our objectives were to develop a method for detection of bisphosphonates in bone and add to the limited information available regarding the disposition of these drugs in the bone of horses. Two horses received clodronate and 2 tiludronate disodium. Postmortem collection of bones and teeth occurred either 4 or 30 d post drug administration. Additionally, postmortem blood, synovial fluid, aqueous humor, and bone samples from racehorses with various histories of bisphosphonate administration were collected, and concentrations determined using the developed LC-MS/MS method. Bisphosphonates were detected in bones and teeth tested at 4 and 30 d. In a postmortem sample, clodronate was detected in bone from a horse with reported administration 18 mo prior; clodronate was not detected in other sample types collected from this horse. Bisphosphonates reside in bone for extended periods of time, which could lead to potential long-term effects, increasing the potential for bone fractures in young and/or athletic horses.

Effect of bisphosphonate on hip fracture in patients with osteoporosis or osteopenia according to age: a meta-analysis and systematic review

This meta-analysis and systematic review investigated the efficacy of bisphosphonates on the incidence of hip fracture (IHF) in patients of different ages with osteoporosis or osteopenia. We searched Web of Science, Embase, the Cochrane Database, and PubMed from inception to January 10, 2021, for trials reporting the effects of bisphosphonates on the IHF. We included only randomized, double-blind, placebo-controlled clinical trials. We pooled data using a random-effects meta-analysis with risk ratios (RRs) and reported 95% CIs. We also used the Cochran Q and I² statistics to assess the heterogeneity in the results of individual studies. The primary endpoints were the total numbers of people in the bisphosphonates and placebo groups and the numbers of IHFs during the follow-up periods. Bisphosphonates reduced the IHF with an overall effect (RR: 0.66; 95% CI: 0.56 to 0.77; zoledronic acid: RR: 0.60; 95% CI: 0.46 to 0.78; risedronate: RR: 0.74; 95% CI: 0.59 to 0.94, and alendronate: RR: 0.61; 95% CI: 0.40 to 0.95). The result of the heterogeneity assessment was I²=0, p=0.97. In all age groups (all ages, ≥55 years old, ≥65 years old), bisphosphonates reduced the IHF. In the ≥55 years old and ≥65 years old age groups, the RR and 95% CI were 0.63 and 0.43 to 0.93, and 0.60 and 0.44 to 0.81, respectively. Bisphosphonate reduced the IHF in the general population and all age groups (≥55 years old and ≥65 years old). Zoledronic acid, risedronate and alendronate reduced the IHF in osteoporosis or osteopenia populations. The association between bisphosphonate and the IHF does not appear to be influenced by age.

Current Applications and Selected Technical Details of Dual-Energy X-Ray Absorptiometry

The application of dual-energy X-ray absorptiometry (DXA) examinations in the assessment of bone mineral density (BMD) in the lumbar spine, hip, and forearm is the basic diagnostic method for recognition of osteoporosis. The constant development of DXA technique is due to the aging of societies and the increasing importance of osteoporosis as a public health problem. In order to assess the degree of bone demineralization in patients with hyperparathyroidism, forearm DXA examination is recommended. The vertebral fracture assessment (VFA) of the thoracic and lumbar spine, performed by a highly-skilled technician, is an interesting alternative to the X-ray examination. The DXA total body examination can be useful in the evaluation of fat redistribution among patients after bariatric surgery, in patients infected with HIV and receiving antiretroviral therapy, and in patients with metabolic diseases and suspected to have sarcopenia. The assessment of visceral adipose tissue (VAT) and detection of abdominal aortic calcifications may be useful in the prediction of cardiovascular events. The positive effect of anti-resorptive therapy may affect some parameters of DXA hip structure analysis (HSA). Long-term anti-resorptive therapy, especially with the use of bisphosphonates, may result in changes in the DXA image, which may herald atypical femur fractures (AFF). Reduction of the periprosthetic BMD in the DXA measurements can be used to estimate the likelihood of loosening the prosthesis and periprosthetic fractures. The present review aims to present current applications and selected technical details of DXA.

Bisphosphonates, Old Friends of Bones and New Trends in Clinics

Bisphosphonates, used for a long time in osteoporosis management, are currently the target of intensive research, from pre-formulation studies to more advanced stages of clinical practice. This review presents an overview of the contributions of this family of compounds to human health, starting with the chemistry and clinical uses of bisphosphonates. Following this, their pharmacology is described, highlighting administration-borne handicaps and undesirable effects. The last three sections of the review describe the research efforts that seek to curb delivery-related issues and expand bisphosphonate use. Innovative routes and strategies of administration, such as nano-encapsulation for oral intake or injectable cements for local or in-bone delivery are presented, as well as the latest results of case studies or preclinical studies proposing new therapeutic indications for the clinically approved bisphosphonates. Finally, a selection of anti-infectious bisphosphonate new drug candidates is shown, with focus on the molecules reported in the last two decades.

Pharmacological Management of Postmenopausal Osteoporosis: a Level I Evidence Based - Expert Opinion

Objectives: Postmenopausal osteoporosis carries a high risk of fractures, which decrease quality of life and are associated with high morbidity, mortality, and economic burden. The best pharmacological treatment options to manage and prevent osteoporotic fractures remain still unclear. The present study investigated the efficacy and safety of the most commonly employed drugs in the management of postmenopausal osteoporosis. Methods: Only RCTs comparing different drugs for the management of postmenopausal osteoporosis were included. Data from 76 RCTs (205,011 patients) were collected. The mean follow-up was 27.6 ± 14.9 months. Results: Denosumab reported the lowest rate of non-vertebral fractures (LOR -1.57), Romosozumab the lowest rate of vertebral fractures (LOR 1.99), and Ibandronate the lowest rate of hip fractures (LOR0.18). Serious adverse events resulted in the lowest in the Raloxifene group (LOR 3.11), while those leading to study discontinuation were lowest in the Romosozumab cohort (LOR 2.65). Conclusions: Denosumab resulted in most effective, particularly in reducing the occurrence of non-vertebral fractures. Romosozumab and Ibandronate resulted best to prevent, respectively, vertebral fractures and hip fractures. Adverse events leading to study discontinuation were less frequent in the Romosozumab and Denosumab groups, while Raloxifene and Alendronate showed a lower incidence of serious adverse events overall. Level of evidence: I, Bayesian network meta-analysis of RCTs.

The Effect of Bisphosphonates on Fracture Healing Time and Changes in Bone Mass Density: A Meta-Analysis

BACKGROUND

Osteoporosis is a common complication of acute fracture, which can lead to fracture delayed union or other complications and resulting in poor fracture healing. Bisphosphate is a common anti-osteoporosis drug, but its application in fracture patients is still controversial because of its inhibitory effect on bone resorption.

METHOD

Studies were acquired from literature databases in accordance with established inclusion criteria. Standard mean difference (SMD) and 95% confidence intervals (Cls) were calculated to evaluate the effectiveness of the bisphosphonates treatment in fracture patients. Data analysis was conducted with the Review Manager 5.4.1 software.

RESULTS

A total of 16 studies involving 5022 patients obtained from selected databases were examined. As expected, bisphosphate had no significant effect on fracture healing time, but it could significantly increase BMD and prevent osteoporosis. Meanwhile, bisphosphate can inhibit both bone resorption and bone formation markers, resulting in low bone turnover state.

CONCLUSION

This meta-analysis showed that bisphosphonate have no significant effect on fracture healing time but they do increase the changes in BMD and reduce bone synthesis and resorption markers. Early application of bisphosphonates after injury in the appropriate patient population should be considered.

History of etidronate

Etidronate is a non-nitrogen-containing bisphosphonate. Because it binds with calcium and inhibits crystal formation and dissolution, it was considered by Procter & Gamble as an additive to toothpaste (to prevent build-up of tartar) and detergent (to bind calcium and increase sudsing in "hard" water). The first clinical use (1968) was for fibrodysplasia ossificans progressiva. The first approved clinical use (1977) was for treatment of Paget's disease of bone. Other approved indications are hypercalcemia of malignancy and heterotopic ossification, with a host of off-label uses (including fibrous dysplasia, periodontal disease, multiple myeloma, neuropathic arthropathy, pulmonary microlithiasis, diabetic retinopathy, bone metastases, melorheostosis, urinary stone disease, periodontal disease, etc.). Unique among bisphosphonates, etidronate (oral therapy) results in hyperphosphatemia, increased tubular reabsorption of phosphorus and increased levels of 1,25-dihydroxyvitamin D. The dose that reduces bone resorption is close to the dose that impairs mineralization; prolonged high-dose use can result in osteomalacia and bone fractures. Intermittent cyclic etidronate for osteoporosis resulted in favorable changes in bone density and histomorphometry (no mineralization defect) as well as a decrease in vertebral fracture rates in postmenopausal women with osteoporosis. Later studies showed similar effects in men with osteoporosis and patients with glucocorticoid-induced osteoporosis. Although its use for osteoporosis has given way to newer bisphosphonates and other agents, because of its unique properties, it remains the bisphosphonate of choice for treatment of heterotopic ossification.

The Pharmacologic Management of Osteoporosis in Primary Biliary Cholangitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Osteoporosis is a common complication of primary biliary cholangitis (PBC) yet evidence for effective therapy is lacking. We sought to review all randomized controlled trials evaluating pharmacotherapy against placebo or no intervention for treatment of osteoporosis in PBC.

METHODOLOGY

A comprehensive database search was conducted from inception through 29 March 2017. The primary outcome was incidence of fractures; secondary outcomes were change in bone mineral density (BMD) and adverse events. We assessed studies for risk of bias, graded quality of evidence, and used meta-analysis to obtain overall effect by pooling studies of the same drug class.

RESULTS

We identified 11 randomized controlled trials evaluating bisphosphonates (3), hormone replacement therapy (2), ursodeoxycholic acid (1), obeticholic acid (1), cyclosporin A (1), vitamin K (1), calcitriol (1), and sodium fluoride (1). No intervention significantly reduced fractures compared to control. Although significant improvement in BMD was seen in one study with alendronate, a third-generation bisphosphonate, no significant improvement was seen on pooled analysis of all bisphosphonates including first-generation bisphosphonates (standard mean difference 0.41, p = 0.68). On pooled analysis, hormone replacement therapy modestly improved lumbar BMD (standard mean difference 0.69, p = 0.02), but with significantly increased adverse events (odds ratio 8.82, p = 0.01).

CONCLUSIONS

There is a lack of high-quality evidence supporting the efficacy of any treatment of osteoporosis in PBC. This may be explained by lack of power in the included studies. However, our current understanding of PBC-related osteoporosis indicates that it results from decreased bone formation, which may explain the attenuated effect of traditional antiresorptive agents. Future studies should investigate newer anabolic bone agents.

Bone Health in Patients With Liver Diseases

Osteoporosis is the most common bone disease in chronic liver disease (CLD) resulting in frequent fractures and leading to significant morbidity in this population. In addition to patients with cirrhosis and chronic cholestasis, patients with CLD from other etiologies may be affected in the absence of cirrhosis. The mechanism of osteoporosis in CLD varies according to etiology, but in cirrhosis and cholestatic liver disease it is driven primarily by decreased bone formation, which differs from the increased bone resorption seen in postmenopausal osteoporosis. Direct toxic effects from iron and alcohol play a role in hemochromatosis and alcoholic liver disease, respectively. Chronic inflammation also has been proposed to mediate bone disease in viral hepatitis and nonalcoholic fatty liver disease. Treatment trials specific to osteoporosis in CLD are small, confined to primary biliary cholangitis and post-transplant patients, and have not consistently demonstrated a benefit in this population. As it stands, prevention of osteoporosis in CLD relies on the mitigation of risk factors such as smoking and alcohol use, treatment of underlying hypogonadism, and encouraging a healthy diet and weight-bearing exercise. The primary medical intervention for the treatment of osteoporosis in CLD remains bisphosphonates though a benefit in terms of fracture reduction has never been shown. This review outlines what is known regarding the pathogenesis of bone disease in CLD and summarizes current and emerging therapies.

Bisphosphonates for Secondary Prevention of Osteoporotic Fractures: A Bayesian Network Meta-Analysis of Randomized Controlled Trials

Purpose

To investigate the comparative efficacies of the five most commonly used bisphosphonates for the secondary prevention of osteoporotic fractures in a Bayesian network meta-analysis.

Methods

Five databases and the reference lists of all acquired articles from inception to July 2017 were searched. A Bayesian random-effects model was employed, and vertebral, hip and nonvertebral nonhip fractures were assessed by odds ratios (ORs) and 95%credible intervals. Furthermore, with respect to each endpoint, rank probabilities for each bisphosphonate were evaluated using the surface under the cumulative ranking curve (SUCRA) value.

Results

Thirteen eligible studies were identified involving 11,822 patients with osteoporotic fractures. Overall in the pairwise meta-analyses, bisphosphonate use significantly reduced the risk of new vertebral, hip, and nonvertebral nonhip fractures, with ORs and 95% confidence intervals of 0.56 (0.49–0.64), 0.69 (0.48–0.98), and 0.82 (0.70–0.97), respectively. In network meta-analyses, significant differences were found between placebo and any one of the five bisphosphonates for new vertebral fractures. The rank probability plot and the SUCRA calculation results suggested that alendronate was the best intervention (14.6%) for secondary prevention of vertebral fractures, followed by zoledronate (15.3%) and etidronate (22.1%). In terms of the incidence of new hip fractures, alendronate was associated with the lowest incidence (18.5%), followed by zoledronate (43.1%) and risedronate (52.5%). However, zoledronate ranked lowest (16.6%) regarding the incidence of new nonvertebral nonhip fractures, followed by risedronate (23.8%) and alendronate (44.1%).

Conclusions

Bisphosphonates show significant efficacy for secondary prevention of new vertebral fractures, and alendronate is most likely to be successful at secondary prevention of vertebral and hip fractures compared with the other four bisphosphonates.

Bisphosphonates-much more than only drugs for bone diseases

α,α-Bisphosphonates (BPs) are well established in the treatment of bone diseases such as osteoporosis and Paget's disease. Their successful application originates from their high affinity to hydroxyapatite. While the initially appreciated features of BPs are already beneficial to many patients, recent developments have further expanded their pleiotropic applications. This review describes the background of the interactions of BPs with bone cells that form the basis of the classical treatment. A better understanding of the mechanism behind their interactions allows for the parallel application of BPs against bone cancer and metastases followed by palliative pain relief. Targeted therapy with bone-seeking BPs coupled with a diagnostic agent in one particle resulted in theranostics which is also described here. For example, in such a system, BP moieties are bound to contrast agents used in magnetic resonance imaging or radionuclides used in positron emission tomography. In addition, another example of the pleiotropic function of BPs which involves targeting the imaging agents to bone tissues accompanied by pain reduction is presented in this work.

Role of Bisphosphonates in Postmenopausal Women with Osteoporosis to Prevent Future Fractures: A Literature Review

Postmenopausal women who have osteoporosis are at increased risk of future fractures. Bisphosphonates are drugs that are used to treat osteoporosis by acting on the osteoclasts to inhibit bone resorption. Several studies have shown that bisphosphonates can maintain or even increase bone mineral density in osteoporosis patients. This review study analyzed the literature on clinical experiments with bisphosphonate therapy in postmenopausal women to determine if these drugs are efficacious in preventing future fractures. Four out of five studies found that women treated with bisphosphonates were at a decreased risk of future fractures, and six of six studies found that bisphosphonate therapy increases bone mineral density relative to placebo control. Although further work is warranted to understand the level of bone mineral density increase that is associated with fracture prevention, this study implies that bisphosphonate therapy can be used to help prevent future fractures in postmenopausal osteoporotic women. The study is significant in that it helps to underscore the efficacy of bisphosphonate therapy in postmenopausal women, and it may be generalizable to other populations with osteoporosis who are at increased risk of fractures.

Etidronate protects chronic ocular hypertension induced retinal oxidative stress and promotes retinal ganglion cells growth through IGF-1 signaling pathway

Glaucoma is a common heterogeneous eye disorder that may lead to irreversible blindness. In the present study, we examined whether etidronate, a member of bisphosphonates, may have neuroprotective effects in in vivo and in vitro rat model of glaucoma. In an in vivo setting, chronic ocular hypertension (COH) was induced in adult rat retina. We discovered that systemic injection of etidronate reduced COH-induced retinal oxidative stress, including caspase-3 activity and MDA level, as well as promoted retinal ganglion cell survival. In an in vitro setting, neonatal retinal ganglion cell was incubated with etidronate. We found etidronate incubation promoted neurite growth, upregulated IGF-1 and p-IGF-1R protein expressions in retinal ganglion cell. In addition, application of a selective IGF-1R antagonist effectively blocked the pro-neuronal effect of etidronate on retinal ganglion cell growth, and reduced p-IGF-1R protein expression. Thus, our results demonstrated that etidronate might reduce retinal oxidative stress and promote retinal neuronal growth through IGF-1 signaling pathway. Future work may define its clinical feasibility to treating human patients with glaucoma.

Osteoporosis in primary biliary cholangitis

Primary biliary cholangitis (PBC) is an autoimmune cholestatic liver disease with multiple debilitating complications. Osteoporosis is a common complication of PBC resulting in frequent fractures and leading to significant morbidity in this population, yet evidence for effective therapy is lacking. We sought to summarize our current understanding of the pathophysiology of osteoporosis in PBC, as well as current and emerging therapies in order to guide future research directions. A complete search with a comprehensive literature review was performed with studies from PubMed, EMBASE, Web of Science, Cochrane database, and the Countway Library. Osteoporosis in PBC is driven primarily by decreased bone formation, which differs from the increased bone resorption seen in postmenopausal osteoporosis. Despite this fundamental difference, current treatment recommendations are based primarily on experience with postmenopausal osteoporosis. Trials specific to PBC-related osteoporosis are small and have not consistently demonstrated a benefit in this population. As it stands, prevention of osteoporosis in PBC relies on the mitigation of risk factors such as smoking and alcohol use, as well as encouraging a healthy diet and weight-bearing exercise. The primary medical intervention for the treatment of osteoporosis in PBC remains bisphosphonates though a benefit in terms of fracture reduction has never been shown. This review outlines what is known regarding the pathogenesis of bone disease in PBC and summarizes current and emerging therapies.

The Prevention and Therapy of Osteoporosis: A Review on Emerging Trends from Hormonal Therapy to Synthetic Drugs to Plant-Based Bioactives

Osteoporosis is one of the major health problems worldwide. It is characterized by increased bone fragility and loss of bone matter due to the action of osteoclast cells, which are associated with modified hormone levels and factors such as aging. Bisphosphonates are the primary treatment for osteoporosis. Apart from bisphosphonates, hormone therapy, calcitonin treatment, selective estrogen receptor modulators (SERMs), and strontium ranelate (SR) are some of the other treatments available for osteoporosis. However, these treatments have some side effects, such as oily skin, fluid retention, nausea, long-term toxicity, and even prostate cancer in males, and thus natural therapies that incur fewer side effects are sought. Phytochemicals, antioxidants, and other plant-based bioactives are important in the human diet. They are abundant in fruits and help against various chronic diseases, including bone disorders. Other providers of these important compounds are the medicinal plant parts. In this article, we highlight the various species of plants and herbs that are useful for the treatment of osteoporosis. The prospect of using these plant-based bioactives in amelioration of osteoporosis as an alternative to hormonal and synthetic drug-based therapy is also discussed.

Effectiveness of anti-osteoporotic drugs to prevent secondary fragility fractures: systematic review and meta-analysis

Patients with osteoporotic fractures have an increased risk for secondary fractures. However, a rigorous study that assesses the effectiveness of individual osteoporotic drugs in preventing subsequent fractures is lacking. The purpose of this review was to analyze the effectiveness of anti-osteoporotic drugs in preventing secondary fractures. We searched for randomized controlled trials that showed the incidence of secondary fractures while using anti-osteoporotic drugs (bisphosphonates, selective estrogen receptor modulators, parathyroid hormone (PTH), or calcitonin) in MEDLINE, Embase.com , and Cochrane Central Register databases. We estimated risk ratios (RR) and numbers needed to treat (NNT) to prevent secondary fractures. Twenty-six studies met our eligibility criteria. There was a significant reduction in RR (0.38-0.77) after the use of anti-osteoporotic drugs for secondary vertebral fractures. Bisphosphonates and PTH significantly reduced the risk of a secondary non-vertebral fracture (RR 0.59 and 0.64). PTH needed the fewest number of patients to be treated to prevent a secondary vertebral fracture (NNT: 56). Our study demonstrated the effectiveness of anti-osteoporotic agents included in our systematic review in preventing secondary vertebral fractures. Bisphosphonates and PTH were most effective in preventing non-vertebral fractures. We suggest that clinicians should prescribe these drugs to prevent secondary vertebral/non-vertebral fractures.

The efficacy and safety of vertebral fracture prevention therapies in post-menopausal osteoporosis treatment: Which therapies work best? a network meta-analysis

Objectives

Osteoporosis has become an increasing concern for older people as it may potentially lead to osteoporotic fractures. This study is designed to assess the efficacy and safety of ten therapies for post-menopausal women using network meta-analysis.

Methods

We conducted a systematic search in several databases, including PubMed and Embase. A random-effects model was employed and results were assessed by the odds ratio (OR) and corresponding 95% confidence intervals (CI). Furthermore, with respect to each outcome, each intervention was ranked according to the surface under the cumulative ranking curve (SUCRA) value.

Results

With respect to preventing new vertebral fractures (NVF), all ten drugs outperformed placebo, and etidronate proved to be the most effective treatment (OR 0.24, 95% CI 0.14 to 0.39). In addition, zoledronic acid and parathyroid hormone ranked higher compared with the other drugs. With respect to preventing clinical vertebral fractures (CVF), zoledronic acid proved to be the most effective drug (OR = 0.25, 95% CI 0.08 to 0.92), with denosumab as a desirable second option (OR = 0.48, 95% CI 0.22 to 0.96), when both were compared with placebo. As for adverse events (AE) and severe adverse events (SAE), no significant difference was observed. According to SUCRA, etidronate ranked first in preventing CVF; parathyroid hormone and zoledronic acid ranked highly in preventing NVF and CVF. Raloxifene was safe with a high rank in preventing AEs and SAEs though performed unsatisfactorily in efficacy.

Conclusions

This study suggests that, taking efficacy and safety into account, parathyroid hormone and zoledronic acid had the highest probability of satisfactory performance in preventing osteoporotic fractures.

Cite this article: G. Wang, L. Sui, P. Gai, G. Li, X. Qi, X. Jiang. The efficacy and safety of vertebral fracture prevention therapies in post-menopausal osteoporosis treatment: Which therapies work best? a network meta-analysis. Bone Joint Res 2017;6:452–463. DOI: 10.1302/2046-3758.67.BJR-2016-0292.R1.

Are outcomes reported in surgical randomized trials patient-important? A systematic review and meta-analysis

BACKGROUND

The dangers of using surrogate outcomes are well documented. They may have little or no association with their patient-important correlates, leading to the approval and use of interventions that lack efficacy. We sought to assess whether primary outcomes in surgical randomized controlled trials (RCTs) are more likely to be patient-important outcomes than surrogate or laboratory-based outcomes.

METHODS

We reviewed RCTs assessing an operative intervention published in 2008 and 2009 and indexed in MEDLINE, EMBASE or the Cochrane Central Register of Controlled Trials. After a pilot of the selection criteria, 1 reviewer selected trials and another reviewer checked the selection. We extracted information on outcome characteristics (patient-important, surrogate, or laboratory-based outcome) and whether they were primary or secondary outcomes. We calculated odds ratios (OR) and pooled in random-effects meta-analysis to obtain an overall estimate of the association between patient importance and primary outcome specification.

RESULTS

In 350 included RCTs, a total of 8258 outcomes were reported (median 18 per trial. The mean proportion (per trial) of patient-important outcomes was 60%, and 66% of trials specified a patient-important primary outcome. The most commonly reported patient-important primary outcomes were morbid events (41%), intervention outcomes (11%), function (11%) and pain (9%). Surrogate and laboratory-based primary outcomes were reported in 33% and 8% of trials, respectively. Patient-important outcomes were not associated with primary outcome status (OR 0.82, 95% confidence interval 0.63-1.1, I2 = 21%).

CONCLUSION

A substantial proportion of surgical RCTs specify primary outcomes that are not patient-important. Authors, journals and trial funders should insist that patient-important outcomes are the focus of study.

Osteoporosis treatment: a missed opportunity

Osteoporosis affects 1.2 million Australians and, in 2012, fractures due to osteoporosis and osteopenia in Australians aged over 50 years cost $2.75 billion. Even minor minimal trauma fractures are associated with increased morbidity and mortality. Despite increasing therapeutic options for managing osteoporosis, fewer than 20% of patients with a minimal trauma fracture are treated or investigated for osteoporosis, so under-treatment is extremely common. Fracture risk assessment is important for selecting patients who require specific anti-osteoporosis therapy. Post-menopausal osteoporosis is frequently due to an imbalance in bone remodelling, with bone resorption exceeding bone formation. Antiresorptive drugs reduce the number, activity and lifespan of osteoclasts, and include bisphosphonates, oestrogen, selective oestrogen receptor-modulating drugs, strontium ranelate, and the human monoclonal antibody denosumab. Teriparatide is the only anabolic agent currently available that stimulates osteoblast recruitment and activity; its antifracture efficacy for non-vertebral fractures increases with the duration of therapy for up to 2 years when it is associated with persisting increases in bone formation rate at the tissue level. Newer anabolic agents are imminent and include an analogue of parathyroid hormone-related protein, abaloparatide, and a humanised monoclonal antibody to an inhibitor of bone formation, romosozumab. Selection of anti-osteoporosis therapy should be individualised to patients, and the duration of bisphosphonate therapy has been covered in recent guidelines. The benefits of treatment far outweigh any risks associated with long term treatment. General practitioners need to take up the challenge imposed by osteoporosis and become champions of change to close the evidence-treatment gap.

The Efficacy of Bisphosphonates for Prevention of Osteoporotic Fracture: An Update Meta-analysis

BACKGROUND

The efficacy of bisphosphonates for osteoporotic fracture has been consistently reported in recent randomized controlled trials (RCTs) enrolling hundreds of patients. The objective of this study was to update knowledge on the efficacy of available bisphosphonates in the prevention of vertebral and non-vertebral fractures.

METHODS

An approach "using systematic reviews" on PubMed and Cochrane Library was taken. Twenty-four RCTs investigating the effects of bisphosphonates for the prevention of osteoporotic fracture were included in final analysis. A pairwise meta-analysis was conducted with a random effects model. Subgroup analysis was performed according to the type of bisphosphonate.

RESULTS

The use of bisphosphonate decrease the risk of overall osteoporotic fracture (odds ratio [OR] 0.62; P<0.001), vertebral fracture (OR 0.55; P<0.001) and non-vertebral fracture (OR 0.73; P<0.001). Subgroup analysis indicated that zoledronic acid showed the lowest risk reduction (OR 0.61; P<0.001) for overall osteoporotic fractures but no significance was observed for etidronate (OR 0.34; P=0.127).

CONCLUSIONS

This update meta-analysis re-confirmed that bisphosphonate use can effectively reduce the risk of osteoporotic fracture. However, there is a lack of evidence regarding etidronate for the prevention of osteoporotic fracture.

Bone Health and Osteoporosis: The Role of Vitamin K and Potential Antagonism by Anticoagulants

BACKGROUND

Vitamin K's effects extend beyond blood clotting to include a role in bone metabolism and potential protection against osteoporosis. Vitamin K is required for the gamma-carboxylation of osteocalcin. Likewise, this gamma-carboxylation also occurs in the liver for several coagulation proteins. This mechanism is interrupted by coumarin-based anticoagulants in both the liver and bone.

METHODS

A thorough review of the literature on vitamin K, osteocalcin and their role in bone metabolism and osteoporosis, as well as the potential bone effects of anticoagulant therapy was conducted.

CONCLUSIONS

Epidemiological studies and clinical trials consistently indicate that vitamin K has a positive effect on bone mineral density and decreases fracture risk. Typical dietary intakes of vitamin K are below the levels associated with better BMD and reduced fracture risk; thus issues of increasing dietary intakes, supplementation, and/or fortification arise. To effectively address these issues, large-scale, intervention trials of vitamin K are needed. The effects of coumarin-based anticoagulants on bone health are more ambiguous, with retrospective studies suggesting that long-term therapy adversely affects vertebral BMD and fracture risk. Anticoagulants that do not affect vitamin K metabolism are now available and make clinical trials feasible to answer the question of whether coumarins adversely affect bone. The research suggests that at a minimum, clinicians should carefully assess anticoagulated patients for osteoporosis risk, monitor BMD, and refer them to dietitians for dietary and supplement advice on bone health. Further research is needed to make more efficacious decisions about vitamin K intake, anticoagulant therapy, and bone health.

Comparative efficacy of bisphosphonates in short-term fracture prevention for primary osteoporosis: a systematic review with network meta-analyses

Our network meta-analyses compared the efficacy of different bisphosphonates preventing fractures for primary osteoporosis. By including 36 studies, we found that zoledronic acid seemed the most effective in preventing vertebral fracture, nonvertebral fracture, and any fracture, and alendronate or zoledronic acid seemed the most effective in preventing hip fracture.

INTRODUCTION

This study was conducted in order to analyze the available evidence on the efficacy of bisphosphonates for preventing fractures.

METHODS

We considered randomized trials comparing any bisphosphonate with other bisphosphonate or placebo. We searched Cochrane Library, Embase, and PubMed and manually searched reference list of relevant articles. Pairwise and network meta-analyses were performed. The primary outcome is vertebral fracture. Secondary outcomes include nonvertebral fracture, hip fracture, wrist fracture, and any fracture.

RESULTS

Thirty-six studies were included. Significant difference was found between bisphosphonates for vertebral fracture and nonvertebral fracture (P < 0.0001 and P = 0.04, respectively). Compared with placebo, alendronate, clodronate, ibandronate, minodronate, pamidronate, risedronate, and zoledronic acid significantly prevented vertebral fracture. Zoledronic acid significantly reduced the risk of vertebral fracture, compared with alendronate, clodronate, etidronate, ibandronate, risedronate, and tiludronate (0.65 (0.46, 0.91), 0.53 (0.33, 0.86), 0.45 (0.27, 0.74), 0.52 (0.36, 0.75), 0.59 (0.42, 0.83), and 0.31 (0.21, 0.48), respectively). Compared with etidronate, clodronate and zoledronic acid significantly prevented nonvertebral fracture. Compared with alendronate, zoledronic acid significantly prevented any fracture. The possibility rankings showed that zoledronic ranked first in preventing vertebral fracture, hip fracture, and any fracture, and pamidronate ranked first in preventing nonvertebral fracture and wrist fracture. In the sensitivity analyses, zoledronic acid ranked first in preventing nonvertebral fracture, and alendronate ranked first in preventing hip fracture and wrist fracture.

CONCLUSION

Zoledronic acid seemed the most effective in preventing vertebral fracture, nonvertebral fracture, and any fracture, and alendronate or zoledronic acid seemed the most effective in preventing hip fracture. Uncertainty still remains and future studies are needed to accurately evaluate the comparative efficacy of bisphosphonates.

Use of Etidronate in the Treatment of Postmenopausal Osteoporosis

Objective:

To discuss the use of etidronate, a biphosphonate, in the treatment of women with postmenopausal osteoporosis and to determine its place in therapy when compared with conventional therapies.

Data Sources:

A MEDLINE search was conducted for clinical trials and review articles on biphosphonates in the treatment of osteoporosis.

Study Selection:

Six clinical trials and four review articles were selected because they dealt specifically with a biphosphonate in the treatment of postmenopausal osteoporosis.

Data Synthesis:

The studies provide a look at how the treatment evolved from continuous etidronate therapy to the more accepted intermittent cyclic therapy. The studies showed an increase in bone mass and a decrease in vertebral fractures in women receiving cyclic therapy with etidronate compared with those receiving placebo. In one study, however, a follow-up report one year later revealed that women taking etidronate experienced a 50 percent increase in vertebral fracture rate compared with those receiving placebo. This was a complete reversal from the data collected over the first two years of the study. This follow-up study is useful to point out a major potential concern associated with long-term use of etidronate—that etidronate therapy may cause mineralization defects, which could lead to alterations in bone integrity.

Conclusions:

Etidronate therapy has shown benefit in preserving bone in postmenopausal women. Comparative trials with conventional therapies such as estrogens have not been completed, which makes it difficult to determine etidronate's place in therapy. Long-term trials also are necessary to assess etidronate's potential to cause mineralization defects.

Osteoporosis: A Pharmacotherapy Update

Hormone replacement therapy (HRT) was the gold standard in prevention and treatment of osteoporosis. However, with new data that demonstrate an increased risk of cardiovascular disease, breast cancer, venous thromboembolic disease, and stroke, HRT is no longer first-line therapy for most postmenopausal women. The bisphosphonates and raloxifene are antiresorptive agents that have been proven to increase bone mineral density and decrease fractures. These agents are considered to be the therapy of choice in prevention and treatment of postmenopausal osteoporosis. New dosing regimens for the bisphosphonates may improve adherence. The other dramatic change to the pharmacotherapy of osteoporosis is the approval of an agent that stimulates bone formation. Parathyroid hormone has the potential to significantly alter the current treatment approach. In addition, this article reviews the role of calcitonin and ipriflavone combination therapy and discusses data on investigational agents including ibandronate, zoledronic acid, vitamin K, and strontium ranelate.

Targeted Delivery Systems for Molecular Therapy in Skeletal Disorders

Abnormalities in the integral components of bone, including bone matrix, bone mineral and bone cells, give rise to complex disturbances of skeletal development, growth and homeostasis. Non-specific drug delivery using high-dose systemic administration may decrease therapeutic efficacy of drugs and increase the risk of toxic effects in non-skeletal tissues, which remain clinical challenges in the treatment of skeletal disorders. Thus, targeted delivery systems are urgently needed to achieve higher drug delivery efficiency, improve therapeutic efficacy in the targeted cells/tissues, and minimize toxicities in non-targeted cells/tissues. In this review, we summarize recent progress in the application of different targeting moieties and nanoparticles for targeted drug delivery in skeletal disorders, and also discuss the advantages, challenges and perspectives in their clinical translation.

Effect of low-magnitude whole-body vibration combined with alendronate in ovariectomized rats: a random controlled osteoporosis prevention study

BACKGROUND

Alendronate (ALE) is a conventional drug used to treat osteoporosis. Low-magnitude whole-body vibration (WBV) exercise has been developed as a potential treatment for osteoporosis. The aim of this study was to investigate whether low-magnitude WBV could enhance the protective effect of ALE on bone properties in ovariectomized rats.

METHODS

A total of 128 Sprague-Dawley rats were randomly divided into five groups (SHAM, OVX+VEH, OVX+WBV, OVX + ALE, OVX+WBV+ALE). The level of WBV applied was 0.3 g at 45-55 Hz for 20 min/day, 5 day/week and for 3 months. ALE was administered in dose of 1 mg/Kg once a week. Every four weeks eight rats from each group were sacrificed and their blood and both tibiae were harvested. The expression of osteocalcin and CTX in serum was measured by enzyme-linked immunosorbent assay (ELISA) and the tibiae were subjected to metaphyseal three-point bending and μCT analysis.

RESULTS

Osteocalcin rose after ovariectomy and was not appreciably changed by either alendronate or WBV alone or in combination. Alendronate treatment significantly prevented an increase in CTX. WBV alone treatment did not alter this effect. Compared with the OVX+WBV group, nearly all tested indices such as the BV/TV, TV apparent, Tb.N, Tb.Th, and Conn.D were higher in the OVX+ALE group at week 12.Compared with the OVX+WBV group, certain tested indices such as BV/TV, TV apparent, Tb.N, and Con.D, were higher in the OVX+WBV+ALE group at week 12. At week 12, tibiae treated with WBV+ALE exhibited a significantly higher Fmax compared to the OVX+VEH group, and a significant difference was also found in energy absorption between the OVX+WBV+ALE and OVX+VEH groups.

CONCLUSIONS

Compared with the WBV, ALE was more effective at preventing bone loss and improved the trabecular architecture. However, WBV enhanced the effect of alendronate in ovariectomized rats by inducing further improvements in trabecular architecture.

One-pot and highly regio-selective 1,3-dipole cycloaddition of azomethine ylide generated in situ to tetraethyl vinylidenebisphosphonate (VBP) catalyzed by cerium(iv) oxide

Higly regio-selective heterocyclic bisphosphonates are obtained in moderate yields (30–70%). The structures of the targeted molecules are characterized by NMR (such as COSY, HSQC, and HMBC), IR and MS.

Interventions to improve osteoporosis medication adherence and persistence: a systematic review and literature appraisal by the ISPOR Medication Adherence & Persistence Special Interest Group

This study aims to systematically review, critically appraise and identify from the published literature, the most effective interventions to improve medication adherence in osteoporosis. A literature search using Medline, EMBASE, Cochrane library, and Cumulative Index to Nursing and Allied Health Literature was undertaken to identify prospective studies published between January 1, 1999 and June 30, 2012. We included studies on adult users of osteoporosis medications that tested a patient adherence intervention (e.g., patient education, intensified patient care, different dosing regimens) and reported quantitative results of adherence. The Delphi list was modified to assess the quality of studies. Of 113 articles identified, 20 studies fulfilled the inclusion criteria. The most frequent intervention was education (n = 11) followed by monitoring/supervision (n = 4), drug regimens (n = 2), drug regimens and patient support (n = 1), pharmacist intervention (n = 1), and electronic prescription (n = 1). Although patient education improved medication adherence in four studies, two large-scale randomized studies reported no benefits. Simplification of dosing regimens (with and without patient support program) was found to have a significant clinical impact on medication adherence and persistence. Monitoring/supervision showed no impact on medication persistence while electronic prescription and pharmacist intervention increased medication adherence or persistence. In conclusion, this review found that simplification of dosing regimens, decision aids, electronic prescription, or patient education may help to improve adherence or persistence to osteoporosis medications. We identified wide variation of quality of studies in the osteoporosis area. The efficacy of patient education was variable across studies, while monitoring/supervision does not seem an effective way to enhance medication adherence or persistence.

New horizons in fracture risk assessment

Fracture is the clinical outcome of concern in osteoporosis, a disease variably defined over the last 30 years, mostly in terms of bone mineral density (BMD). However, an 'osseocentric' view of the condition may have hampered our understanding of how best to identify patients at the greatest risk of fragility fracture. More recently, the identification of a number of clinical risk factors for fragility fracture and the creation of fracture risk assessment tools, such as FRAX®, QFracture and Garvan have helped in a move towards clinically useful definitions, using the common currency of 10-year major osteoporotic and 10-year hip fracture risks. However, there are a large number of available fracture risk assessment tools and there remain few validation studies comparing their performance. The National Institute for Health and Clinical Excellence has recently advocated the use of these methods in case finding and studies are underway in their clinical application. It seems likely that the operational definition of osteoporosis must now include fracture risk, which will never replace fracture incidence as a measure of clinical efficacy but may be used in future studies to define patient groups likely to benefit from intervention. We still need to understand more about the performance of these tools, particularly in the context of specific patient groups, such as those with vertebral osteoporosis, the frail, those who fall and patients with secondary osteoporosis.

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.

Proportion of osteoporotic post-menopausal women at increased risk for upper GI adverse events associated with bisphosphonate therapy

Background- The bisphosphonate alendronate has been associated with higher rates of adverse oesophageal effects when used in the community setting compared to what was observed in the clinical trials. Patients with a history of gastroesophageal problems or who are concurrently using an NSAID therapy may be at increased risk for the gastroesophageal problems associated with alendronate use. This study assesses the proportion of post-menopausal women in the community with osteoporosis that are at increased risk for gastroesophageal adverse effects associated with alendronate.Methods- The administrative database for the Quebec government drug benefit program was used to identify a cohort of 5400 post menopausal women aged 65 years or older who were using the bisphosphonate etidronate for the treatment of osteoporosis. Patients were evaluated for the presence of either risk factor, chronic GI drug therapy use (a marker for prior gastroesophageal problems) or chronic NSAID use.Findings- 31% of women taking etidronate were also chronically using GI drug therapies and 50% were using NSAIDs; 18% of the women were using all three drugs.Interpretation- Many osteoporosis patients in the community setting who are candidates for bisphosphonate therapy might be considered at increased risk for alendronate's gastroesophageal adverse effects. This may account for differences in pre-marketing and postmarketing event rates. Copyright (c) 2000 John Wiley & Sons, Ltd.

A Bayesian analysis of bisphosphonate effects and cost-effectiveness in post-menopausal osteoporosis

Objective - Effects of oral bisphosphonates on the rate of vertebral fractures in post-menopausal osteoporotic women have been found in clinical trials. We wanted to compare the effects of two bisphosphonates, alendronate and etidronate, and calculate the price difference that would give the same cost-effectiveness for the two drugs. We also intended to give, by means of Bayesian statistics, probability distributions and point and interval estimates for key parameters.Methods - We used published, double-blind, randomized placebo controlled studies describing the results of occurrence of vertebral fractures at 3-year follow-up in post-menopausal women taking bisphosphonates. Four studies were identified, including altogether 3510 women. The women had either suffered a fracture at entry or had a bone density at least 2.5 SD below the mean value for young women. Two of the studies dealt with alendronate and two with etidronate.Results - According to three of the studies, the number of women out of 100 avoiding vertebral fractures during a 3-year observation period varied from two to seven. The fourth study did not contain the necessary data. The four studies showed that, for the incidence rate, the multiplicative treatment effects were respectively 0.45, 0.74, 0.40 and 0.36, where values less than 1 indicate positive treatment effects. Using data from all four studies, a comparison of the two drugs gave a point estimate of 0.247 with 95% credibility interval (CI): -0.051 to 0.496 for a difference in effect in favour of alendronate measured in terms of risk ratio of fracture and 0.302 (CI: 0.099 to 0.539) measured as incidence rate ratio. Based on two studies, showing about the same prevalence of fractures in the control groups, the difference in the risk difference between the two drugs was 0.028 (CI: -0.039 to 0.079).Conclusions - Bisphosphonates effectively reduce risk of new vertebral fractures, but alendronate is somewhat more effective than etidronate. To obtain equal cost-effectiveness alendronate should be priced 40 - 70% higher than etidronate. Copyright (c) 2000 John Wiley & Sons, Ltd.

Downregulation of the inflammatory response by CORM-3 results in protective effects in a model of postmenopausal arthritis

CO-releasing molecules (CORMs) are a new class of drugs able to release small amounts of CO in biological systems. We have shown previously that one of these molecules, CORM-3, exerts anti-inflammatory effects in animal models. The aim of this study was to assess the effects of CORM-3 on bone metabolism in a model of postmenopausal rheumatoid arthritis osteoporosis. Ovariectomy was followed by collagen-induced arthritis in female DBA-1/J mice. Animals showing arthritis on day 22 after immunization were then randomized into control and treatment groups. CORM-3 was administered at 10 mg/kg, intraperitoneally, once a day. Alendronate was administered at 100 μg/kg, orally, once a day. On days 36 and 50 after immunization, animals were killed and tissues analyzed. The arthritic score was significantly reduced by CORM-3 but not by alendronate treatment. Histopathological analyses indicated that both compounds reduced cellular infiltration and cartilage degradation. Local bone erosion and reduction in TNFα levels were seen for CORM-3 on day 50 and for alendronate on day 36. Serum levels of COMP, IL-6, MMP-3, CTX-I, alkaline phosphatase, and osteocalcin were decreased by both treatments, whereas TNFα levels were reduced by CORM-3 and TRAP-5b by alendronate. Micro-computed tomographic analysis showed protective effects on trabecular bone, which were more prominent for CORM-3 on day 36 and for alendronate on day 50. Our results suggest that CORMs represent a novel anti-inflammatory strategy to counteract joint bone erosion with partial protective effects on systemic bone loss in postmenopausal rheumatoid arthritis.

Quantitative PET Imaging Using (18)F Sodium Fluoride in the Assessment of Metabolic Bone Diseases and the Monitoring of Their Response to Therapy

Studies of bone remodeling using bone biopsy and biochemical markers of bone turnover measured in serum and urine are important for investigating how new treatments for osteoporosis affect bone metabolism. Positron emission tomography with (18)F sodium fluoride ((18)F NaF PET) for studying bone metabolism complements these conventional methods. Unlike biochemical markers, which measure the integrated response to treatment across the whole skeleton, (18)F NaF PET can distinguish changes occurring at sites of clinically important osteoporotic fractures. Future studies using (18)F NaF PET may illuminate current clinical problems, such as the possible association between long-term treatment with bisphosphonates and atypical fractures of the femur.

Osteoporosis imaging: state of the art and advanced imaging

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures.

Osteoporosis imaging: state of the art and advanced imaging

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures.

The relative efficacy of nine osteoporosis medications for reducing the rate of fractures in post-menopausal women

BACKGROUND

In the absence of head-to-head trials, indirect comparisons of randomized placebo-controlled trials may provide a viable option to assess relative efficacy. The purpose was to estimate the relative efficacy of reduction of fractures in post-menopausal women, and to assess robustness of the results.

METHODS

A systematic literature review of multiple databases identified randomized placebo-controlled trials with nine drugs for post-menopausal women. Odds ratio and 95% credibility intervals for the rates of hip, non-vertebral, vertebral, and wrist fractures for each drug and between drugs were derived using a Bayesian approach. A drug was ranked as the most efficacious if it had the highest posterior odds ratio, or had the highest effect size.

RESULTS

30 studies including 59,209 patients reported fracture rates for nine drugs: alendronate (6 studies), denosumab (1 study), etidronate (8 studies), ibandronate (4 studies), raloxifene (1 study), risedronate (7 studies), strontium (2 study), teriparatide (1 study), and zoledronic acid (1 study). The drugs with the highest probability of reducing non-vertebral fractures was etidronate and teriparatide while the drugs with the highest probability of reducing vertebral, hip or wrist fractures were teriparatide, zoledronic acid and denosumab. The drugs with the largest effect size for vertebral fractures were zoledronic acid, teriparatide and denosumab, while the drugs with the highest effect size for non-vertebral, hip or wrist fractures were alendronate or risedronate. Estimates were consistent between Bayesian and classical approaches.

CONCLUSION

Teriparatide, zoledronic acid and denosumab have the highest probabilities of being most efficacious for non-vertebral and vertebral fractures, and having the greatest effect sizes. The estimates from indirect comparisons were robust to differences in methodology.