Reduction in the risk of clinical fractures after a single dose of zoledronic Acid 5 milligrams

Zoledronic acid for hip fracture during initial hospitalization

Inpatient zoledronic acid (IP-ZA) administered during the initial fracture hospitalization significantly improves the osteoporosis treatment rate. Clinical outcomes of IP-ZA after hip fracture remain uncertain. Here we report a cohort study that emulated a randomized controlled trial using real-world data and evaluated the risk of all-cause-mortality and radiologically confirmed subsequent new fractures among patients hospitalized for a hip fracture who had received IP-ZA as compared with propensity-matched controls. A total of 654 patients who had received IP-ZA and 6877 controls (for whom anti-osteoporosis treatment was indicated but no IP-ZA started during index hospitalization) were included in the study. The primary cohort comprised 652 IP-ZA patients (IP-ZA group) and 1926 matched controls (untreated group), with 71.7% female 92.1% White participants, with a mean age of 80.9 years. Cumulative all-cause mortality over the 24-month follow-up for the IP-ZA group was 12.3% and 20.7% for the untreated group (hazard ratio [HR], 0.62; 95% CI, 0.49-0.78, p < .001). A total of 585 (89.7%) patients in IP-ZA group received only a single dose of ZA during the 24 months, and the death rate of this single dose group was 13.3%, which was significantly lower than that of the untreated group (HR, 0.70; 95% CI, 0.55-0.89, p = .003). Rates of radiologically confirmed cumulative subsequent new vertebral fractures were 2.0% in the IP-ZA group and 5.4% in the untreated group (HR, 0.40; 95% CI, 0.22-0.71, p = .001). A similarly lower rate of new vertebral fractures was seen in the single dose subgroup (1.9% vs 5.4%; HR, 0.44; 95% 0.24-0.82, p = .008). IP-ZA, administered during the initial hospitalization for hip fracture, was associated with lower all-cause-mortality and risk of radiologically confirmed subsequent new vertebral fractures, and thus offers a mechanism to narrow the treatment gap in patients having sustained a hip fragility fracture.

Intermittent dosing of zoledronic acid based on bone turnover marker assessment reduces vertebral and non-vertebral fractures

Previous studies have demonstrated that the administration of zoledronic acid (ZOL) once yearly for 3 years or once over 3 years, yields similar antifracture efficacy. Bone turnover markers can predict the antifracture efficacy of antiresorptive agents, with procollagen type 1 N-terminal propeptide (P1NP) being the most useful marker. In this retrospective cohort study, we explored the effects of intravenous dosing of ZOL guided by serum (S)-P1NP assessment on bone mineral density (BMD) and fractures. Consenting patients (N = 202, mean age 68.2 years) with osteoporosis were treated with ZOL for an average of 4.4 (range 2-8) years. S-P1NP and BMD were measured at baseline and every 1-2 years. We assessed the number of subsequent vertebral and nonvertebral fractures in the 2-year time periods. The number of patients assessed was 202, 147, 69, and 29 at years 1-2, 3-4, 5-6, and 7-8, respectively. A new ZOL infusion was given if S-P1NP exhibited values above 35 μg/L. BMD increased by 6.2% (SD 4.0) over the first 2 years and stabilized in years 2-8 (P <.05). Median S-P1NP exhibited an initial reduction from 58.0 to 31.3 μg/L at year 2 and then increased to 39.0 μg/L at years 7-8. Compared with fractures observed in the last 2 years before baseline, fracture rates exhibited consistent reductions, for vertebral fractures odds ratio (OR) [95% confidence interval] = 0.61 [0.47, 0.80], P <.001 and for nonvertebral fractures OR = 0.23 [0.18, 0.31], P <.001. In conclusion, intermittent dosing of intravenous ZOL based on the assessment of S-P1NP with cut-off at 35 μg/L resulted in an initial increase followed by a stable BMD, suppression of S-P1NP, and stable reduction of fractures for 8 years. Only 39% of patients needed more than one infusion. This approach reduces healthcare costs and might also reduce the risk of rare side effects such as osteonecrosis of the jaw and atypical femoral fracture.

Duration of fracture prevention after zoledronate treatment in women with osteopenia: observational follow-up of a 6-year randomised controlled trial to 10 years

BACKGROUND

We previously identified that zoledronate administered at 18-month intervals reduced fragility fractures by a third in a 6-year trial of women older than 65 years with osteopenia. This extension aims to identify the persistence of these effects.

METHODS

Of the 2000 ambulant, community dwelling, postmenopausal women older than 65 years recruited in Auckland, New Zealand, with T-scores at the total hip or femoral neck in the range -1·0 to -2·5, we invited participants who received four doses of intravenous zoledronate, completed follow-up to year 6 of the core trial, did not have metabolic bone disease (other than osteoporosis), and were not using bone-active drugs into this 4-year observational study extension, during which further treatment was at the discretion of their own doctors. Participants were asked to notify study staff of any new fractures and were telephoned at 7·5 years and 9·0 years to update their health status. Participants were then invited to an onsite visit at 10·0 years. Fractures and other health events were documented at each contact and analysed in all women who entered the extension, and bone mineral density (BMD; analysed in participants without notable use of bone-active medications who attended an onsite visit at 10 years) and turnover markers (measured from fasting morning blood in a random subset of 50 participants) were measured at year 10.

FINDINGS

Of the 1000 women randomly assigned to receive zoledronate in the core trial, 796 participants were eligible for the extension, of whom 762 (96%) entered the extension between Sept 24, 2015, and Dec 13, 2017. Mean follow-up duration was 4·24 years (SD 0·57, range 0·61-6·55; final follow-up on May 25, 2022). 727 (91%) of participants were assessed at 10 years. 25 women died during the extension, six withdrew for medical reasons, and four were lost to follow-up. 92 women suffered 114 non-vertebral fractures during the extension. Non-vertebral fracture rates increased from a nadir of 15 fractures per 1000 woman-years (95% CI 10-21) in the last 2 years of the core trial to 24 fractures (17-33) in years 6-8 and 42 fractures (32-53) in years 8-10, similar to that in the placebo group in the last 2 years of the core trial. Total hip BMD (relative risk per 0·1 g/cm2 0·73, 95% CI 0·57-0·93; p=0·011) and a previous history of non-vertebral fracture (1·74, 1·12-2·69; p=0·013) at year 6 predicted incident fractures but change in total hip BMD did not. Total hip BMD decreased from 4·2% above study baseline to 0·8% above baseline (p<0·0001) during the extension. Turnover markers were not useful for predicting BMD loss in individuals. Osteonecrosis of the jaw or atypical femoral fractures did not occur in any participants.

INTERPRETATION

The reduced fracture rates following zoledronate in the core trial were substantially maintained for 1·5-3·5 years after the last zoledronate infusion, but not thereafter.

FUNDING

Health Research Council of New Zealand.

Methodological guidance for the use of real-world data to measure exposure and utilization patterns of osteoporosis medications

Observational studies of osteoporosis medications can provide critical real-world evidence (RWE) that fills knowledge gaps left by clinical trials. However, careful consideration of study design is needed to yield reliable estimates of association. In particular, obtaining valid measurements of exposure to osteoporosis medications from real-world data (RWD) sources is complicated due to different medication classes, formulations, and routes of administration, each with different pharmacology. Extended half-lives of bisphosphonates and extended dosing of denosumab and zoledronic acid require particular attention. In addition, prescribing patterns and medication taking behavior often result in gaps in therapy, switching, and concomitant use of osteoporosis therapies. In this review, we present important considerations and provide specialized guidance for measuring osteoporosis drug exposures in RWD. First, we compare different sources of RWD used for osteoporosis drug studies and provide guidance on identifying osteoporosis medication use in these data sources. Next, we provide an overview of osteoporosis pharmacology and how it can influence decisions on exposure measurement within RWD. Finally, we present considerations for the measurement of osteoporosis medication exposure, adherence, switching, long-term exposures, and drug holidays using RWD. Ultimately, a thorough understanding of the differences in RWD sources and the pharmacology of osteoporosis medications is essential to obtain valid estimates of the relationship between osteoporosis medications and outcomes, such as fractures, but also to improve the critical appraisal of published studies.

Zoledronic acid sequential to teriparatide may promote greater inhibition of bone resorption than zoledronic acid alone

Background

Teriparatide (TPTD) should be followed by an antiresorptive to maximize bone mineral density gain and anti-fracture protection. Infrequent zoledronic acid (ZOL) administration has demonstrated effectiveness. The duration of ZOL effect following TPTD is unknown.

Objective

To evaluate the effect of ZOL on bone resorption marker in a post-TPTD versus ZOL-alone scenario in osteoporotic patients.

Design

Retrospective cohort study.

Methods

Patients treated with TPTD followed by ZOL (TPTD-ZOL) or with a single ZOL infusion were identified in the database of a tertiary referral center. Clinical and laboratory data, including C-terminal telopeptide of type I collagen (CTX) following ZOL treatment, were compared.

Results

Twenty-six patients (93% women) treated with TPTD-ZOL and 41 with ZOL were comparable in age (median 70.1 versus 69.6 years, p = 0.6) and sex. Timing of CTX measurement post-ZOL was the same, median 1.0 year. CTX was lower following TPTD-ZOL (median 142.1 versus 184.2 pg/mL, p = 0.005). In a multivariable regression model (controlled for baseline characteristics), pretreatment with TPTD strongly predicted CTX <150 pg/mL, 1 year following ZOL (odds ratio = 7.5, 95% CI 1.3-58.1, p = 0.03). In a subgroup with sequential CTX measurements following one ZOL, significantly lower levels persisted in the TPTD-ZOL group for a median of 4.4 years follow-up.

Conclusion

ZOL-administered sequential to TPTD yielded deeper and more prolonged bone resorption suppression than ZOL alone. Prospective data are needed to confirm whether in a sequential treatment scenario, subsequent ZOL dosing interval should be less frequent.

Safety of Inpatient Zoledronic Acid in the Immediate Postfracture Setting

CONTEXT

Zoledronic acid (ZA) administered during the initial hospitalization for a fragility fracture improves the osteoporosis pharmacotherapy rate. Distinguishing the safety profile of inpatient ZA (IP-ZA) in this context is crucial if this approach is to be widely adopted.

OBJECTIVE

To study the acute safety profile of IP-ZA.

METHODS

An observational study of patients admitted to the Massachusetts General Hospital with fragility fractures who were eligible to receive IP-ZA. Patients were treated with or without IP-ZA. Acetaminophen, either as a single pre-ZA dose or standing multiple-doses-per-day regimen for 48 hours or longer after ZA infusion, was also administered along with protocolized vitamin D and calcium supplementation. Changes in body temperature, serum creatinine, and serum calcium were measured.

RESULTS

A total of 285 consecutive patients, meeting inclusion and exclusion criteria, are included in this analysis; 204 patients received IP-ZA. IP-ZA treatment was associated with a transient mean rise of body temperature of 0.31 °C on the day following its administration. Temperatures above 38 °C were seen in 15% of patients in the IP-ZA group and 4% in the nontreated group. Standing multiple-doses-per-day but not a single pre-ZA dose of acetaminophen effectively prevented this temperature increase. IP-ZA did not affect serum creatinine levels. Mean levels of serum total calcium and albumin-corrected calcium decreased by 0.54 mg/dL and 0.40 mg/dL, respectively, at their nadirs (Day 5). No patient experienced symptomatic hypocalcemia.

CONCLUSION

IP-ZA along with standing multiple-doses-per-day acetaminophen, administered to patients in the immediate postfracture period, is not associated with significant acute adverse effects.

Call to action: a five nations consensus on the use of intravenous zoledronate after hip fracture

Currently in the UK and Ireland, after a hip fracture most patients do not receive bone protection medication to reduce the risk of refracture. Yet randomised controlled trial data specifically examining patients with hip fracture have shown that intravenous zoledronate reduces refracture risk by a third. Despite this evidence, use of intravenous zoledronate is highly variable following a hip fracture; many hospitals are providing this treatment, whilst most are currently not. A range of clinical uncertainties, doubts over the evidence base and practical concerns are cited as reasons. This paper discusses these concerns and provides guidance from expert consensus, aiming to assist orthogeriatricians, pharmacists and health services managers establish local protocols to deliver this highly clinically and cost-effective treatment to patients before they leave hospital, in order to reduce costly re-fractures in this frail population.

Inpatient Zoledronic Acid and Integrated Orthopedic and Fracture Liaison Services Improve Osteoporosis Treatment Rates

CONTEXT

Fragility fractures increase risks for future fractures, morbidity, and mortality. Available pharmacotherapy for underlying osteoporosis is safe and effective but underused.

OBJECTIVE

To improve pharmacotherapy rate representing secondary prevention of osteoporotic fractures.

METHODS

This single-center, observational, follow-up study included patients with fragility fractures admitted to the Massachusetts General Hospital between February 2016 and December 2019. For patients admitted to the orthopedics service with fragility fracture, the Massachusetts General Hospital Fracture Liaison Service (FLS) was systematically consulted. Initial outpatient follow-up with FLS was established in conjunction with the orthopedic postoperative follow-up visit. Patients at risk for failing timely outpatient follow-up were administered zoledronic acid (ZA) during the index fracture hospitalization. The main outcome measures were percentage of patients with fragility fracture(s) started on pharmacotherapy for osteoporosis and average length of stay and 30-day readmission rate of patients treated with ZA.

RESULTS

Compared with baseline (8-11%) and reference (5-20%) rates, integration of FLS to the orthopedics service, along with appropriate inpatient administration of ZA, increased the pharmacotherapy rate to 70% (412/589) among eligible patients with verified treatment status. Inpatient ZA administration neither affected the average length of stay nor 30-day readmission rate. Treatment status of 37.9% (471/1240) of the study patients remained unknown due to lack of or unknown follow-up.

CONCLUSION

Integration of a FLS and orthopedics services along with inpatient ZA administration improved the osteoporosis pharmacotherapy rate among patients with fragility fracture(s) who often had obstacles for outpatient follow-up.

Early bisphosphonate therapy post proximal femoral fracture fixation does not impact fracture healing: a systematic review and meta-analysis

BACKGROUND

There is conjecture on the optimal timing to administer bisphosphonate therapy following operative fixation of low-trauma hip fractures. Factors include recommendations for early opportunistic commencement of osteoporosis treatment, and clinician concern regarding the effect of bisphosphonates on fracture healing. We performed a systematic review and meta-analysis to determine if early administration of bisphosphonate therapy within the first month post-operatively following proximal femur fracture fixation is associated with delay in fracture healing or rates of delayed or non-union.

METHODS

We included randomized controlled trials examining fracture healing and union rates in adults with proximal femoral fractures undergoing osteosynthesis fixation methods and administered bisphosphonates within 1 month of operation with a control group. Data were pooled in meta-analyses where possible. The Cochrane Risk of Bias Tool and the GRADE approach were used to assess validity.

RESULTS

For the outcome of time to fracture union, meta-analysis of three studies (n = 233) found evidence for earlier average time to union for patients receiving early bisphosphonate intervention (MD = -1.06 weeks, 95% CI -2.01--0.12, I²  = 8%). There was no evidence from two included studies comprising 718 patients of any difference in rates of delayed union (RR 0.61, 95% CI 0.25-1.46). Meta-analyses did not demonstrate a difference in outcomes of mortality, function or pain.

CONCLUSIONS

We provide low-level evidence that there is no reduction in time to healing or delay in bony union for patients receiving bisphosphonates within 1 month of proximal femur fixation.

EXTENSIVE EXPERTISE IN ENDOCRINOLOGY: Osteoporosis management

Fractures occur in about half of older White women, and almost a third of older White men. However, 80% of the older individuals who have fractures do not meet the bone density definition of osteoporosis, suggesting that this definition is not an appropriate threshold for offering treatment. Fracture risk can be estimated based on clinical risk factors with or without bone density. A combination of calculated risk, fracture history, and bone density is used in treatment decisions. Medications available for reducing fracture risk act either to inhibit bone resorption or to promote bone formation. Romosozumab is unique in that it has both activities. Bisphosphonates are the most widely used interventions because of their efficacy, safety, and low cost. Continuous use of oral bisphosphonates for >5 years increases the risk of atypical femoral fractures, so is usually punctuated with drug holidays of 6-24 months. Denosumab is a further potent anti-resorptive agent given as 6-monthly s.c. injections. It is comparable to the bisphosphonates in efficacy and safety but has a rapid offset of effect after discontinuation so must be followed by an alternative drug, usually a bisphosphonate. Teriparatide stimulates both bone formation and resorption, substantially increases spine density, and reduces vertebral and non-vertebral fracture rates, though data for hip fractures are scant. Treatment is usually limited to 18-24 months, followed by the transition to an anti-resorptive. Romosozumab is given as monthly s.c. injections for 1 year, followed by an anti-resorptive. This sequence prevents more fractures than anti-resorptive therapy alone. Because of cost, anabolic drugs are usually reserved for those at very high fracture risk. 25-hydroxyvitamin D levels should be maintained above 30 nmol/L, using supplements if sunlight exposure is limited. Calcium intake has little effect on bone density and fracture risk but should be maintained above 500 mg/day using dietary sources.

Anti-Mullerian Hormone as Predictor of Future and Ongoing Bone Loss During the Menopause Transition

The menopause transition in women is a period of significant bone loss, with rapid declines in bone mineral density (BMD) commencing a year before the final menstrual period (FMP). Changes in menstrual bleeding patterns cannot reliably tell us if this rapid bone loss has begun or is imminent. We hypothesized that low circulating levels of anti-Mullerian hormone (AMH), which decline as women approach the FMP, would be associated with future and ongoing rapid bone loss. We used data from The Study of Women's Health Across the Nation, a multisite, multi-ethnic, prospective cohort study of the menopause transition to test this hypothesis. Adjusted for age, body mass index, race/ethnicity, and study site, every 50% decrement in AMH level in premenopause and early perimenopause was associated with 0.14% per year faster decline over the following 3 to 4 years in lumbar spine BMD and 0.11% per year faster decline in femoral neck BMD (p < 0.001 for both). AMH in late perimenopause was not associated with the rate of future BMD decline. AMH was also associated with the magnitude of ongoing bone loss, measured as percent of peak BMD lost by the end of the next 2 to 3 years. Every 50% decrement in AMH level was associated with 0.22% additional loss in spine BMD in premenopause, 0.43% additional loss in early perimenopause, and 0.50% additional loss in late perimenopause (p < 0.001 for all three). If a woman will lose more of her peak BMD than the site-specific least significant change (LSC) at either the lumbar spine or femoral neck by the next 2 to 3 years, then AMH below 100 pg/mL will detect it with sensitivity of 50% in premenopause, 80% in early perimenopause, and 98% in late perimenopause. These findings suggest that AMH measurement can help flag women at the brink of significant bone loss for early intervention. © 2022 American Society for Bone and Mineral Research (ASBMR).

New national osteoporosis guidance-implications for geriatricians

Fragility fractures are painful, debilitating, often life-changing and accounted for an estimated 2.4% of pre-pandemic health care spending in the UK. Those who are older, frail and multimorbid have the highest fracture risk and therefore the most to gain from anti-osteoporosis treatments to reduce this risk. Currently, an unacceptable treatment gap exists between those eligible for and those who receive treatment. This commentary discusses the major changes to the new, National Institute for Health and Care Excellence accredited, UK National Osteoporosis Guideline Group (NOGG) guidance (published March 2022) most relevant to the management of older people's bone health. Changes include intervention thresholds; using fracture probabilities from FRAX; for patients too frail to undergo DXA; greater emphasis on vertebral fracture detection and the use of intravenous zoledronate as a first-line anti-osteoporosis therapy; the new concept of 'very high fracture risk' which should prompt consideration of use of parenteral anti-osteoporosis therapy; new guidance regarding anabolic treatment options; concerns regarding denosumab cessation; and the urgent need to get patients with a fragility fracture onto treatment to reduce re-fracture risk with follow-up to check tolerance and ensure adherence.

Zoledronic Acid Ameliorates the Bone Turnover Activity and Periprosthetic Bone Preservation in Cementless Total Hip Arthroplasty

The administration of zoledronic acid (ZA) to patients who received cementless total hip arthroplasty (THA) has been reported to reduce bone turnover markers (BTMs) and increase bone mineral density (BMD). The effects of two-dose ZA versus placebo on cementless THA patients were analyzed in this five-year extension study. Alkaline phosphatase (ALP), osteocalcin (OC), procollagen 1 intact N-terminal propeptide (P1NP), serum calcium, renal function, radiological findings, and functional outcomes were compared in 49 patients, and the periprosthetic BMD of seven Gruen zones were compared in 19 patients. All the patients had normal renal function and calcium levels at their final follow-up. The mean ALP level in the ZA group was significantly lower at the fifth year, mean OC levels were significantly lower at the second and fifth year, and mean P1NP levels were significantly lower from 6 weeks to 5 years as compared with the control group. Fifth-year BMD levels were not found to be different between the ZA and control groups. The BMD Change Ratios in the ZA group were significantly increased in Gruen zone 6 at 1, 2, and 5 years. Our study results suggest that short-term ZA treatment with a subsequent 4-year drug holiday may inhibit serum BTMs and provide periprosthetic bone preservation at five years without adverse events.

Bone Mineral Density and Bone Turnover 10 Years After a Single 5 mg Dose or Two 5-Yearly Lower Doses of Zoledronate in Osteopenic Older Women: An Open-Label Extension of a Randomized Controlled Trial

Intravenous zoledronate reduces fracture risk (5 mg at 18-month intervals) and prevents bone loss (doses of 1 to 5 mg for 3 to >5 years), but the duration of action of a single 5 mg dose and the effects of lower doses beyond 5 years are unknown. We report the second open-label extension (years 5 to 10) of a 2-year randomized, multidose, placebo-controlled, double-blinded trial. A total of 116 older women who completed 5 years of participation either continued observation without further treatment (zoledronate 5 mg and placebo at baseline) or received repeat doses of 1 or 2.5 mg zoledronate (zoledronate 1 mg and zoledronate 2.5 mg at baseline, respectively). Outcomes were spine, hip, and total body bone mineral density (BMD) and serum markers of bone turnover. After a single 5 mg dose of zoledronate, mean BMD at the lumbar spine and total hip was maintained at or above baseline levels for 9 and 10 years, respectively. The mean level of the bone resorption marker β-C-terminal telopeptide of type I collagen (β-CTX) was at least 25% lower than that in the placebo group for 9 years. In women administered 5-yearly doses of 2.5 mg zoledronate, mean BMD at the total hip and lumbar spine was maintained at or above baseline levels for 9 and 10 years, respectively. Redosing with 1 or 2.5 mg zoledronate at 5 years reduced bone turnover markers for 3 to 4 years. BMD increased for 3 to 4 years after redosing with 1 mg zoledronate. In the group given 5-yearly 2.5 mg zoledronate, β-CTX was at least 20% lower than that in the placebo group for 10 years. Both a single baseline 5 mg dose of zoledronate and 5-yearly doses of 1 and 2.5 mg zoledronate prevented bone loss at hip and spine for 8 to 10 years in older postmenopausal women. Clinical trials to evaluate the effects on fracture risk of these very infrequent and lower doses of zoledronate are justified. © 2021 American Society for Bone and Mineral Research (ASBMR).

Cost-effectiveness of 3 versus 6 years of zoledronic acid treatment before bisphosphonate holiday for women with osteoporosis

We evaluated the cost-effectiveness of recurrent periods of 3 versus 6 years of zoledronic acid treatment prior to 3-year bisphosphonate holidays for US postmenopausal women with osteoporosis and femoral neck BMD T-scores between - 2.5 and - 3.5. We found that cycles of 3 years of treatment followed by holidays is likely to be the more cost-effective option.

INTRODUCTION

We compared the effectiveness and cost-effectiveness of cycles of 3 years versus 6 years of zoledronic acid treatment prior to 3-year bisphosphonate holidays for US postmenopausal women with osteoporosis.

METHODS

We developed an individual-level state-transition microsimulation cost-effectiveness model to compare treatment strategies over the lifetime of recurrent periods of 3 years of zoledronic acid followed by 3-year holidays (zoledronic acid 3/3), recurrent periods of 6 years of zoledronic acid followed by 3-year holidays (zoledronic acid 6/3), and no zoledronic acid treatment for women with osteoporosis and femoral neck BMD T-scores between - 2.5 and - 3.5.

RESULTS

Base-case analysis and all key parameter sensitivity analysis findings for every treatment initiation age evaluated (50, 60, 70, and 80) revealed that zoledronic acid 3/3 was consistently the most cost-effective strategy, assuming a willingness-to-pay of $100,000 per quality-adjusted life-year (QALY). In general, the zoledronic acid 3/3 and 6/3 strategies were relatively close in effectiveness (QALYs) over the lifetime; however, lifetime direct health care costs were on average approximately $2000 lower for the 3/3 strategy. Probabilistic sensitivity analysis results revealed that the zoledronic acid 3/3 strategy was favored in greater than 70% of the iterations for a willingness-to-pay threshold of $100,000/QALY for all treatment initiation ages evaluated.

CONCLUSIONS

After 3 years of zoledronic acid treatment for postmenopausal women with osteoporosis and femoral neck BMD T-scores between - 2.5 and - 3.5, taking 3-year holidays before restarting another treatment cycle is likely to be more cost-effective over the lifetime than cycles of 6 years of treatment prior to 3-year holidays.

All-cause mortality risk in aged femoral intertrochanteric fracture patients

Introduction

The 1-year mortality rate after femoral intertrochanteric fracture is higher than that of femoral neck fracture, which also belongs to hip fracture (Cui et al. in Arch Osteoporos 14(1):55, 2019). With the application of the concept of co-management model of orthopedics and geriatrics, the short-term and long-term mortality of all types of hip fractures has decreased (Van Heghe et al. in Calcif Tissue Int, 2021, https://doi.org/10.1007/s00223-021-00913-5). However, the mortality of Chinese femoral intertrochanteric fracture patients under this model has not been reported in the literatures.

Aim

This paper aims to study the risk factors of postoperative all-cause mortality in aged patients with femoral intertrochanteric fracture under the co-management model of orthopedics and geriatrics.

Materials and methods

This is a single-center prospective cohort study based on the real world, under the co-management of orthopedics and geriatrics, 363 patients aged ≥ 65 years with femoral intertrochanteric fracture were enrolled and followed up for 2–3 years; 52 patients were lost to follow up. Age, gender, body mass index (BMI), history of comorbidities, hip Bone Mineral Density (BMD), fracture history, 25(OH)D level, hemoglobin level, anti-osteoporosis treatment were risk factors to be tested. Kaplan–Meier survival curves and multivariate Cox proportional hazards models were constructed to analyze the impact of factors on all-cause mortality.

Results

(1) Most of the dead patients were older (the mean age was 83.4 years, compared with 79.8 years for surviving patients), with more complications and without anti-osteoporosis medication; gender, pre-fracture history, BMI, total hip BMD, hemoglobin, 25(OH)D had no difference between the dead and the living patients. (2) Elderly patients with Intertrochanteric fracture can benefit from the early treatment of Zoledronic Acid (within 3 days after the operation).

Conclusion

Under the co-management of orthopedics and geriatrics, to Chinese patients with Femoral Intertrochanteric fracture, Doctors should pay more attention to their age and chronic disease, and give anti-osteoporosis treatment if allowed.

The Effects of Osteoporotic and Non-osteoporotic Medications on Fracture Risk and Bone Mineral Density

Osteoporosis is a highly prevalent bone disease affecting more than 37.5 million individuals in the European Union (EU) and the  United States of America (USA). It is characterized by low bone mineral density (BMD), impaired bone quality, and loss of structural and biomechanical properties, resulting in reduced bone strength. An increase in morbidity and mortality is seen in patients with osteoporosis, caused by the approximately 3.5 million new osteoporotic fractures occurring every year in the EU. Currently, different medications are available for the treatment of osteoporosis, including anti-resorptive and osteoanabolic medications. Bisphosphonates, which belong to the anti-resorptive medications, are the standard treatment for osteoporosis based on their positive effects on bone, long-term experience, and low costs. However, not only medications used for the treatment of osteoporosis can affect bone: several other medications are suggested to have an effect on bone as well, especially on fracture risk and BMD. Knowledge about the positive and negative effects of different medications on both fracture risk and BMD is important, as it can contribute to an improvement in osteoporosis prevention and treatment in general, and, even more importantly, to the individual's health. In this review, we therefore discuss the effects of both osteoporotic and non-osteoporotic medications on fracture risk and BMD. In addition, we discuss the underlying mechanisms of action.

Faster Lumbar Spine Bone Loss in Midlife Predicts Subsequent Fracture Independent of Starting Bone Mineral Density

CONTEXT

Bone mineral density (BMD) decreases rapidly during menopause transition (MT), and continues to decline in postmenopause.

OBJECTIVE

This work aims to examine whether faster BMD loss during the combined MT and early postmenopause is associated with incident fracture, independent of starting BMD, before the MT.

METHODS

The Study of Women's Health Across the Nation, a longitudinal cohort study, included 451 women, initially premenopausal or early perimenopausal, and those transitioned to postmenopause. Main outcome measures included time to first fracture after early postmenopause.

RESULTS

In Cox proportional hazards regression, adjusted for age, body mass index, race/ethnicity, study site, use of vitamin D and calcium supplements, and use of bone-detrimental or -beneficial medications, each SD decrement in lumbar spine (LS) BMD before MT was associated with a 78% increment in fracture hazard (P = .007). Each 1% per year faster decline in LS BMD was related to a 56% greater fracture hazard (P = .04). Rate of LS BMD decline predicted future fracture, independent of starting BMD. Women with a starting LS BMD below the sample median, and an LS BMD decline rate faster than the sample median had a 2.7-fold greater fracture hazard (P = .03). At the femoral neck, neither starting BMD nor rate of BMD decline was associated with fracture.

CONCLUSION

At the LS, starting BMD before the MT and rate of decline during the combined MT and early postmenopause are independent risk factors for fracture. Women with a below-median starting LS BMD and a faster-than-median LS BMD decline have the greatest fracture risk.

Zoledronic acid for prevention of bone loss in patients receiving bariatric surgery

Purpose

Bariatric surgery is an effective treatment for severe obesity but causes substantial bone loss and increased risk of fractures. To date, there have been no studies examining whether pharmacologic treatments can prevent bone loss after bariatric surgery. We performed an exploratory study to examine the preliminary safety and efficacy of zoledronic acid (ZOL), a potent anti-resorptive bisphosphonate, to suppress bone turnover markers (BTM) and prevent declines in bone mineral density (BMD) after Roux-en-Y gastric bypass (RYGB) surgery.

Methods

We performed an open-label pilot study of pre-operative ZOL in postmenopausal women with obesity who were planning RYGB (n = 4). A single dose of zoledronic acid 5 mg was given intravenously prior to RYGB. Serum bone biochemistries including C-telopeptide (CTX) and procollagen type 1 N-terminal propeptide (P1NP) were measured at multiple timepoints throughout the 24-week study. BMD was also obtained at the spine and hip by dual-energy x-ray absorptiometry (DXA) and at the trabecular spine by quantitative computed tomography (QCT) at pre-operative baseline and 24 weeks. Results were compared against pre-operative baseline and against changes among RYGB historical controls (n = 10).

Results

At 2 weeks after RYGB, there was a nonsignificant trend for CTX and P1NP levels to be lower than baseline levels in the ZOL group. By 24 weeks after RYGB, however, participants who received ZOL had a significant increase in CTX above pre-operative baseline (+0.228 ± 0.117 ng/dL, p = 0.030) but this CTX rise was less than that observed in the controls (+0.601 ± 0.307 ng/dL, p = 0.042 between groups). Despite ZOL use, participants had significant areal BMD loss at the total hip as compared to pre-operative baseline (-4.2 ± 1.5%, p = 0.012) that was similar in magnitude to total hip BMD loss in the controls (-5.5 ± 3.9%, p = 0.005). There was a suggestion that the ZOL group might be protected against trabecular spine volumetric bone loss as compared to the control group (+4.8 ± 8.0% vs. -5.9 ± 7.0%, p = 0.075 between groups). Serum calcium, 25-hydroxyvitamin D, and parathyroid hormone did not change in either group. No hypocalcemia or serious adverse events were reported after ZOL.

Conclusion

In this proof of concept study, a single dose of ZOL prior to RYGB appeared to transiently mitigate but not fully prevent high bone turnover in the acute postoperative period. At 24 weeks after RYGB, our preliminary data suggest that ZOL was not sufficient to prevent bone loss at the hip, although it may preserve bone density at the trabecular spine. Further prospective, controlled studies are needed to confirm our findings and to identify the best strategies for preventing bone loss in bariatric patients receiving RYGB.

The TOPAZ study: a home-based trial of zoledronic acid to prevent fractures in neurodegenerative parkinsonism

The Trial of Parkinson’s And Zoledronic acid (TOPAZ, https://clinicaltrials.gov/ct2/show/NCT03924414) is a unique collaboration between experts in movement disorders and osteoporosis to test the efficacy of zoledronic acid, an FDA-approved parenteral treatment for osteoporosis, for fracture prevention in people with neurodegenerative parkinsonism. Aiming to enroll 3,500 participants age 65 years or older, TOPAZ is one of the largest randomized, placebo-controlled clinical trials ever attempted in parkinsonism. The feasibility of TOPAZ is enhanced by its design as a U.S.- wide home-based trial without geographical limits. Participants receive information from multiple sources, including specialty practices, support groups and websites. Conducting TOPAZ in participants’ homes takes advantage of online consent technology, the capacity to confirm diagnosis using telemedicine and the availability of research nursing to provide screening and parenteral therapy in homes. Home-based clinical research may provide an efficient, convenient, less expensive method that opens participation in clinical trials to almost anyone with parkinsonism.

Hormones and bone loss across the menopause transition

The menopause transition is a critical period for bone health in women, with rapid losses in bone mass and strength occurring over an approximately 3-year window bracketing the date of the final menstrual period. The onset of the rapid bone loss phase is preceded by large changes in sex steroid hormones, measurements of which may be clinically useful in predicting the onset of the rapid loss phase and identifying the women who will lose the most bone mass during this rapid bone loss phase. Here we summarize recent and new findings related to the ability of sex hormone levels to (1) determine if a woman in her 5th decade of life is about to enter or has already entered the rapid phase of bone loss, and (2) if she will lose more than the average amount of bone mass over the menopause transition.

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.

Joint position statement on management of patient with osteoporosis during COVID-19 contingency from the AMMOM, CONAMEGER, FELAEN, FEMECOG, FEMECOT, and ICAAFYD

Infection by SARS-Cov-2 (COVID-19) has affected practically all the world. This joint position statement of Latin American Medical Societies provides an updated guide for the prevention, diagnosis, and treatment of osteoporotic patients in the face of possible clinical scenarios posed by the COVID-19 health crisis.

BACKGROUND

Infection by SARS-Cov-2 (COVID-19) has affected practically all the world. Characterized by high contagiousness, significative morbidity, and mortality in a segment of those infected, it has overwhelmed health services and forced to redirect resources to the emergency while impacting the attention of acute non-COVID-19 and many chronic conditions.

OBJECTIVE

The objective of this study is to provide an updated guide for the prevention, diagnosis, and treatment of osteoporotic patients in the face of possible clinical scenarios posed by the COVID-19 health crisis.

METHODS

A task force, of bone specialists with a wide range of disciplines in the field of osteoporosis and fragility fracture, was convened with the representation of several professional associations, namely, the Mexican Association of Bone and Mineral Metabolism (AMMOM), the National College of Geriatric Medicine (CONAMEGER), the Latin American Federation of Endocrinology (FELAEN), the Mexican Federation of Colleges of Obstetrics and Gynecology (FEMECOG), the Mexican Federation of Colleges of Orthopedics and Traumatology (FEMECOT), and the Institute of Applied Sciences for Physical Activity and Sports of the University of Guadalajara (ICAAFYD). Clinical evidence was collated, and an evidence report was rapidly generated and disseminated. After finding the gaps in the available evidence, a consensus opinion of experts was made. The resulting draft was reviewed and modified accordingly, in 4 rounds, by the participants.

RESULTS

The task force approved the initial guidance statements, with moderate and high consensus. These were combined, resulting in the final guidance statements on the (1) evaluation of fracture risk; (2) stratification of risk priorities; (3) indications of bone density scans and lab tests; (4) initiation and continuation of pharmacologic therapy; (5) interruptions of therapy; (6) treatment of patients with incident fracture; (7) physical therapy and fall prevention; and (8) nutritional interventions.

CONCLUSION

These guidance statements are provided to promote optimal care to patients at risk for osteoporosis and fracture, during the current COVID-19 pandemic. However, given the low level of available evidence and the rapidly evolving literature, this guidance is presented as a "living document" and future updates are anticipated.

Benefits of Bisphosphonate Therapy: Beyond the Skeleton

PURPOSE OF REVIEW

Recent evidence from clinical trials and observational studies raises the possibility that bisphosphonate use might confer a lower risk of cardiovascular disease and cancer, resulting in a mortality benefit. This review summarizes clinical and preclinical studies examining the non-skeletal effects of bisphosphonates.

RECENT FINDINGS

Data from clinical trials are conflicting regarding whether or not bisphosphonates have beneficial effects on mortality, cardiovascular events, or cancer incidence. No clinical trials have assessed these outcomes as primary endpoints, and most trials were shorter than 4 years. Observational data suggest that bisphosphonate users may have lower mortality, delayed progression of vascular calcification and atherosclerotic burden, and reduced incidence of breast and colorectal cancer compared to non-users. Preclinical studies confirm that bisphosphonates can be taken up by macrophages and monocytes, and nitrogen-containing bisphosphonates have the ability to disrupt the mevalonate pathway within these cells. In this manner, bisphosphonates exert anti-atherogenic and anti-cancer effects. Bisphosphonates also appear to exert protective effects on vascular smooth muscle cells and endothelial cells and may have direct cytotoxic effects on cancer cells. The balance of evidence does not support bisphosphonate treatment for the primary purpose of improving non-skeletal outcomes, although appropriately designed controlled trials that further explore this possibility are both justified and required. Patients with skeletal indications for bisphosphonate therapy can be reassured that these agents are not associated with increased mortality, cardiovascular disease, or cancer incidence.

The Effect of Kinesitherapy on Bone Mineral Density in Primary Osteoporosis: A Systematic Review and Meta-Analysis of Randomized Controlled Trial

Objective

Osteoporosis (OP) is a well-established age-related disease, pathologically characterized by bone microarchitectural deterioration, increased fragility, and low BMD. Primary osteoporosis (POP) is the most common type of OP.

Methods

Publications pertaining to the effectiveness of kinesitherapy on BMD in POP from PubMed, SCI, Cochrane Library, Embase, VIP, CNKI, and Wanfang Database were retrieved from their inception to October 2019.

Results

A total of 21 studies with 1840 participants were included. The results of the meta-analysis revealed that kinesitherapy plus antiosteoporosis medications had a positive effect on lumbar spine BMD when the duration of intervention was 6 months (MD = 0.11 g/cm²; 95% CI: 0.06–0.15; P < 0.0001) or >6 months (MD = 0.04 g/cm²; 95% CI: 0.02–0.06; P < 0.0001) compared with antiosteoporosis medications alone. Additional kinesitherapy plus antiosteoporosis medications were associated with improved femoral neck BMD compared with antiosteoporosis medications alone (MD = 0.09 g/cm²; 95% CI: 0.03–0.16; P=0.004).

Conclusions

Kinesitherapy plus antiosteoporosis medications significantly improved lumbar spine and femoral neck BMD in the current low-quality evidence. Additional high-quality evidence is required to confirm the effect of kinesitherapy on BMD in patients with POP.

Zoledronate

Zoledronate is the most potent and most long-acting bisphosphonate in clinical use, and is administered as an intravenous infusion. Its major uses are in osteoporosis, Paget's disease, and in myeloma and cancers to reduce adverse skeletal related events (SREs). In benign disease, it is a first- or second-line treatment for osteoporosis, achieving anti-fracture efficacy comparable to that of the RANKL blocker, denosumab, over 3 years, and it reduces fracture risk in osteopenic older women. It is the preferred treatment for Paget's disease, achieving higher rates of remissions which are much more prolonged than with any other agent. Some trials have suggested that it reduces mortality, cardiovascular disease and cancer, but these findings are not consistent across all studies. It is nephrotoxic, so should not be given to those with significant renal impairment, and, like other potent anti-resorptive agents, can cause hypocalcemia in patients with severe vitamin D deficiency, which should be corrected before administration. Its most common adverse effect is the acute phase response, seen in 30-40% of patients after their first dose, and much less commonly subsequently. Clinical trials in osteoporosis have not demonstrated increases in osteonecrosis of the jaw or in atypical femoral fractures. Observational databases are currently inadequate to determine whether these problems are increased in zoledronate users. Now available as a generic, zoledronate is a cost-effective agent for fracture prevention and for management of Paget's disease, but wider provision of infusion facilities is important to increase patient access. There is a need to further explore its potential for reducing cancer, cardiovascular disease and mortality, since these effects could be substantially more important than its skeletal actions.

A broader strategy for osteoporosis interventions

Approximately 50% of women experience at least one bone fracture postmenopause. Current screening approaches target anti-fracture interventions to women aged >60 years who satisfy clinical risk and bone mineral density criteria for osteoporosis. Intervention is only recommended in 7-25% of those women screened currently, well short of the 50% who experience fractures. Large screening trials have not shown clinically significant decreases in the total fracture numbers. By contrast, six large clinical trials of anti-resorptive therapies (for example, bisphosphonates) have demonstrated substantial decreases in the number of fractures in women not identified as being at high risk of fracture. This finding suggests that broader use of generic bisphosphonates in women selected by age or fracture risk would result in a reduction in total fracture numbers, a strategy likely to be cost-effective. The utility of the current bone density definition of osteoporosis, which neither corresponds with who suffers fractures nor defines who should be treated, requires reappraisal.

The Association between Fast Increase in Bone Turnover During the Menopause Transition and Subsequent Fracture

CONTEXT

Bone turnover increases rapidly during the menopause transition (MT) and plateaus above premenopausal levels in early postmenopause. It is uncertain whether higher bone turnover is associated with fracture in midlife women with near-normal bone mineral density (BMD).

OBJECTIVE

Examine whether faster increases in bone turnover during the MT (2 years before to 2 years after the final menstrual period [FMP]), and greater bone turnover during early postmenopause (≥2 years after the FMP) are risk factors for subsequent fracture, accounting for BMD.

DESIGN AND SETTING

The Study of Women's Health Across the Nation, a longitudinal cohort study of the MT.

PARTICIPANTS

A total of 484 women (initially pre- or early perimenopausal, who transitioned to postmenopause) with bone turnover (urine collagen type I N-telopeptide), BMD, and fracture data.

MAIN OUTCOME MEASURE

Incident fracture after the MT.

RESULTS

Adjusting for age, race/ethnicity, fracture before the MT, cigarette use, body mass index, and study site in Cox proportional hazards regression, each SD increment in the rate of increase in bone turnover during the MT was associated with 24% greater hazard of incident fracture in postmenopause (P = .008). Accounting for the same covariates, each SD increment in bone turnover during early postmenopause was associated with a 27% greater hazard of fracture (P = .01). Associations remained significant after controlling for MT rate of change and early postmenopausal level of BMD.

CONCLUSION

Faster increases in bone turnover during the MT and greater bone turnover in early postmenopause forecast future fractures.

Ten Years of Very Infrequent Zoledronate Therapy in Older Women: An Open-Label Extension of a Randomized Trial

CONTEXT

Intravenous zoledronate prevents bone loss and reduces fracture risk in older adults but the optimal dosing strategy required to achieve each outcome is not known.

OBJECTIVE

To assess the effect of very infrequent zoledronate therapy on bone mineral density (BMD) and markers of bone turnover.

DESIGN AND PARTICIPANTS

An average of 5.5 years after randomization to either a single dose of 5 mg of zoledronateor placebo, 33 of the original cohort of 50 older women with osteopenia entered a 5-year open-label extension study.

SETTING

Academic research center.

INTERVENTION

A 5-mg dose of intravenous zoledronate was administered to all participants.

MAIN OUTCOME MEASURES

BMD and bone turnover were measured annually, generating data over almost 11 years in women who received 5 mg of zoledronate at 0 and 5.5 years (ZZ, n = 16), or placebo at baseline and 5 mg of zoledronate at 5.5 years (PZ, n = 17).

RESULTS

After redosing, BMD in ZZ remained stable, while BMD in PZ increased. At 11 years, changes from baseline BMD in ZZ and PZ were 3.8% (95% confidence interval (CI) 1.1,6.5) and 2.9% (0.3,5.5) at the lumbar spine (P = .61), 0.9% (-1.7,3.5) and -2.8% (-5.3,-0.3) at the total hip (P = .006), and 0.4% (-0.8,1.6) and -0.4% (-1.3,0.5) at the total body (P = .14). Bone turnover markers were similar in the PZ and ZZ groups throughout the 5 years after redosing.

CONCLUSIONS

These results suggest that zoledronate 5 mg administered at a 5.5-year interval prevents bone loss over almost 11 years. Clinical trials to investigate whether very infrequent treatment with zoledronate reduces fracture risk are justified.

Comparison of BMD Changes and Bone Formation Marker Levels 3 Years After Bisphosphonate Discontinuation: FLEX and HORIZON-PFT Extension I Trials

An ASBMR Task Force recommends a drug holiday for certain women treated for ≥5 years with oral alendronate or ≥3 years with intravenous zoledronic acid, with reassessment 2 to 3 years later. It is not known whether changes in bone mineral density (BMD) or bone turnover markers differ after oral or intravenous therapy. Our goal was to compare changes in BMD and procollagen type I N propeptide (PINP) after oral or intravenous bisphosphonate use. In the Fracture Intervention Trial Long-term Extension (FLEX), women who received a mean 5 years of alendronate were randomized to placebo or continued treatment. In the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly-Pivotal Fracture Trial Extension I (HORIZON-PFT E1), women who received 3 years of zoledronic acid were randomized to placebo or continued treatment. We examined the proportion of participants with BMD loss or PINP gain ≥ least significant change (LSC) and those whose values exceeded a threshold (T-score ≤-2.5 or PINP ≥36.0 ng/mL, a premenopausal median value). After 3 years of placebo, the FLEX group had greater mean total hip BMD decreases (-2.3% versus -1.2% in the HORIZON-PFT E1 group, p < 0.01) and greater rises in PINP (+11.6 ng/mL versus +6.7 ng/mL, p < 0.01). There was a greater proportion of individuals in FLEX with total hip BMD loss and PINP increases that exceeded LSC, and PINP values ≥36.0 ng/mL. In contrast, there were small changes in the proportion of women with femoral neck T-scores ≤-2.5 in both groups. In conclusion, 3 years after bisphosphonate discontinuation, a considerable proportion of former alendronate and zoledronic acid users had meaningful declines in total hip BMD and elevations in PINP. Despite a longer treatment course, alendronate may have a more rapid offset of drug effect than zoledronic acid. © 2018 American Society for Bone and Mineral Research.

Management of fracture risk in Parkinson's: A revised algorithm and focused review of treatments

INTRODUCTION

Falls and fractures are a cause of substantial morbidity in Parkinson's. Despite an excess risk of both falls and osteoporosis, people with Parkinson's perceive that they are less likely to fracture than their peers, despite actually being at higher fracture risk. Recognising this increased risk, in 2014 we published an algorithm to guide management of fracture risk in this high-risk population. Recently, the National Osteoporosis Guideline Group (NOGG) published new guidance revising the 10 year fracture probability intervention thresholds for those over 70 years old to 20.3% for major osteoporotic fracture and 5.4% for hip fracture.

METHODS

In light of the new guidance, we have reappraised the use of two fracture prediction tools, Qfracture and FRAX, and have updated the algorithm to guide the management of bone health and fracture risk in people with Parkinson's.

RESULTS

We outline the treatment options available with particular consideration given to Parkinson specific factors that influence treatment choices.

CONCLUSION

This guidance is relevant to all healthcare specialist managing Parkinson's including neurologists, geriatricians and primary care practitioners.

Treating osteoporosis to prevent fractures: current concepts and future developments

Antiresorptive drugs, such as the bisphosphonates and the RANKL inhibitor denosumab, are currently the most widely used osteoporosis medications. These drugs increase bone mineral density (BMD) and reduce the risk of vertebral (by 40-70%), nonvertebral (by 25-40%) and hip fractures (by 40-53%) in postmenopausal women with osteoporosis. Due to the risk of rare side-effects, the use of bisphosphonates has been limited to up to 10 years with oral bisphosphonates and 6 years with intravenous zoledronic acid. Despite their well-proven efficacy and safety, few women at high risk of fracture are started on treatment. Case finding strategies, such as fracture risk-based screening in primary care using the fracture risk assessment tool (FRAX) and Fracture Liaison Services, have proved effective in increasing treatment rates and reducing fracture rates. Recently, anabolic therapy with teriparatide was demonstrated to be superior to the bisphosphonate risedronate in preventing vertebral and clinical fractures in postmenopausal women with vertebral fracture. Treatment with the sclerostin antibody romosozumab increases BMD more profoundly and rapidly than alendronate and is also superior to alendronate in reducing the risk of vertebral and nonvertebral fracture in postmenopausal women with osteoporosis. For patients with severe osteoporosis and high fracture risk, bisphosphonates alone are unlikely to be able to provide long-term protection against fracture and restore BMD. For those patients, sequential treatment, starting with a bone-building drug (e.g. teriparatide), followed by an antiresorptive, will likely provide better long-term fracture prevention and should be the golden standard of future osteoporosis treatment.

Hip fracture rates and time trends in use of anti-osteoporosis medications in Denmark for the period 2005 to 2015: Missed opportunities in fracture prevention

BACKGROUND

Declining use of bisphosphonates (BP) in the United States and Europe may lead to a widening of the treatment gap for osteoporosis and an increase in fracture rates. However, a shift to non-bisphosphonates and to hospital administered i.v. BPs could lead to overestimation of the treatment gap if analyses are based exclusively on BP prescriptions. When a healthcare system successfully narrows the treatment gap by making appropriate use of anti-osteoporosis drugs, we would expect to see declining rates of osteoporotic fractures with much of the decrease being statistically attributable to medication uptake. We analysed a best-case scenario where all use of BPs, denosumab, raloxifene and PTH analogues - including the oncology area - was contrasted with the trend in hip fracture rates. This scenario also considered users of raloxifene and teriparatide as covered by osteoporosis drugs though the primary RCT for raloxifene showed no risk reduction in nonvertebral fractures and the RCT for teriparatide risk reductions for non-vertebral fractures but not hip fracture specifically. Sensitivity analyses were also done.

METHODS

We used aggregate statistics on hip fracture events and total use of the above medications estimating the number of persons potentially covered. The reduction in hip fracture rates attributable to treatment was estimated using the absolute risk reduction (ARR) found in real-world users of oral alendronate in Denmark with the ARR in the FIT primary prevention arm as an alternative scenario.

RESULTS

A plateau in use of osteoporosis medications occurred in 2014. Between 2005 and 2015, hip fracture rates declined by 30%. However, only up to 20% of the observed reduction in hip fracture rates was statistically attributable to treatment even in a best-case scenario. Sensitivity analyses where raloxifene and teriparatide were excluded did not impact on this finding.

DISCUSSION

Anti-osteoporosis treatment in Denmark reached a plateau in 2014 even in a best-case scenario where all dispensations were assumed to be for osteoporosis. Future studies may be able to distinguish between the oncology area and the osteoporosis indication as well as provide a delineation of age and gender demographics among users of hospital administered osteoporosis medications. About 80% of the decline in hip fracture rates appears to be due to factors other than osteoporosis medication. The plateau in use of osteoporosis treatment at a level that is too low to make a meaningful impact on societal fracture burden is problematic given the predicted increased age-specific hip fracture rates.

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.

Cost-effectiveness of single-dose zoledronic acid for nursing home residents with osteoporosis in the USA

OBJECTIVE

To evaluate the cost-effectiveness of routine administration of single-dose zoledronic acid for nursing home residents with osteoporosis in the USA.

DESIGN

Markov cohort simulation model based on published literature from a healthcare sector perspective over a lifetime horizon.

SETTING

Nursing homes.

PARTICIPANTS

A hypothetical cohort of nursing home residents aged 85 years with osteoporosis.

INTERVENTIONS

Two strategies were compared: (1) a single intravenous dose of zoledronic acid 5 mg and (2) usual care (supplementation of calcium and vitamin D only).

PRIMARY AND SECONDARY OUTCOME MEASURES

Incremental cost-effectiveness ratio (ICER), as measured by cost per quality-adjusted life year (QALY) gained.

RESULTS

Compared with usual care, zoledronic acid had an ICER of $207 400 per QALY gained and was not cost-effective at a conventional willingness-to-pay threshold of $100 000 per QALY gained. The results were robust to a reasonable range of assumptions about incidence, mortality, quality-of-life effects and the cost of hip fracture and the cost of zoledronic acid. Zoledronic acid had a potential to become cost-effective if a fracture risk reduction with zoledronic acid was higher than 23% or if 6-month mortality in nursing home residents was lower than 16%. Probabilistic sensitivity analysis showed that the zoledronic acid would be cost-effective in 14%, 27% and 44% of simulations at willingness-to-pay thresholds of $50 000, $100 000 or $200 000 per QALY gained, respectively.

CONCLUSIONS

Routine administration of single-dose zoledronic acid in nursing home residents with osteoporosis is not a cost-effective use of resources in the USA but could be justifiable in those with a favourable life expectancy.

A Review of Osteoporosis in the Older Adult: An Update

Osteoporosis in the elderly population is common. It results in more than 1.5 million fractures per year in the United States. The goal of managing osteoporosis is to prevent fractures. In men, osteoporosis is underrecognized and undertreated. More men than women die every year as a consequence of hip fractures. Bisphosphonates are the first-line treatment of men and women. In the past several years, advances in bone biology have resulted in major therapeutic advances. A review of diagnosis and treatment of osteoporosis is described.

A long-lasting bisphosphonate partially protects periprosthetic bone, but does not enhance initial stability of uncemented femoral stems: A randomized placebo-controlled trial of women undergoing total hip arthroplasty

Low bone quality may compromise the success of cementless total hip arthroplasty in high-risk patients such as elderly women. Zoledronic acid is a long-lasting antiresorptive agent, which is known to reduce short-term periprosthetic bone loss. However, its effect on femoral stem stability is not well known. Forty-nine female patients with a mean age of 68 years (range, 51-85 years) scheduled to undergo cementless total hip arthroplasty due to osteoarthritis were randomized in this double-blind, placebo-controlled trial to receive a single postoperative infusion of zoledronic acid or placebo. Patients were evaluated for up to four years postoperatively for femoral stem migration measured by radiostereometric analysis, bone mineral density (BMD) measured by dual X-ray absorptiometry, functional recovery, and patient-reported outcome scores. Implant survival was determined at nine years postoperatively. Zoledronic acid did not reduce the femoral stem migration that occurred predominantly during the settling period of the first 3-6 months. Subsequently, all femoral stems were radiographically osseointegrated. Zoledronic acid maintained periprosthetic BMD, while the expected loss of periprosthetic bone during the first 12 months was found in controls. Thereafter, periprosthetic BMD of Gruen zone 7 decreased even in the zoledronic acid group but remained 14.6% higher than that in the placebo group at four years postoperatively. Functional recovery was comparable across the groups. At nine years postoperatively, no revision arthroplasty had been performed. In conclusion, in women at high-risk for low BMD, zoledronic acid had a long-lasting, partially protective effect on periprosthetic bone loss, but the treatment did not enhance the initial femoral stem stability.

A Review of Osteoporosis in the Older Adult

Osteoporosis in the elderly population is common. It results in more than 1.5 million fractures per year in the United States. The goal of managing osteoporosis is to prevent fractures. In men, osteoporosis is underrecognized and undertreated. More men than women die every year as a consequence of hip fractures. A review of diagnosis and treatment of osteoporosis is described in this article. Bisphosphonates are the first-line treatment for men and women. In the past several years, advances in bone biology have resulted in major therapeutic advances.

Update on osteoporosis treatment

Treatment of osteoporosis should be directed primarily towards secondary prevention of fractures. The occurrence of drug-related adverse effects for the treatment of osteoporosis has led to a reevaluation of the indications, the duration of treatment and even withdrawal of some drugs from the market. This review has been made from different patient profiles that practitioners will find in usual practice; from patients with hip fracture with cognitive impairment, limitation of their day-to-day living activities and comorbidities, to active patients without any limitations; patients with vertebral fractures and non-vertebral fractures where secondary prevention is highly important. In general, antiresorptive drugs (alendronate and risedronate) will be the first choice. Zoledronate or denosumab will be indicated in cases of digestive intolerance, poor adherence or an increased risk of hip fracture. Teriparatide will be indicated to patients with 2or more previous vertebral fractures or very low bone density.

Duration of antiresorptive activity of zoledronate in postmenopausal women with osteopenia: a randomized, controlled multidose trial

BACKGROUND

Intravenous zoledronate 5 mg annually reduces fracture risk, and 5 mg every 2 years prevents bone loss, but the optimal dosing regimens for these indications are uncertain.

METHODS

We conducted a 3-year open-label extension of a 2-year randomized, placebo-controlled, double-blind study. Late postmenopausal women with osteopenia were assigned to receive a single baseline dose of 1 mg, 2.5 mg or 5 mg of zoledronate or placebo. The primary outcome was change in spine bone mineral density (BMD). Secondary outcomes were changes in hip BMD and serum markers of bone turnover.

RESULTS

The study involved 160 women. Zoledronate increased BMD and reduced markers of bone turnover in a dose-dependent manner. After 2 years, the 1-mg, 2.5-mg and 5-mg zoledronate doses increased spine BMD over placebo by 5.0% (95% confidence interval [CI] 3.0% to 7.0%), 5.7% (95% CI 3.7% to 7.7%) and 5.7% (95% CI 3.7% to 7.6%), respectively; after 5 years, the respective increases were 2.0% (95% CI -1.1% to 5.0%), 2.2% (95% CI -1.0% to 5.4%) and 5.1% (95% CI 2.2% to 8.1%). After 2 years, the 1-mg, 2.5-mg and 5-mg zoledronate doses increased total hip BMD over placebo by 2.6% (95% CI 1.3% to 3.9%), 4.1% (95% CI 2.9% to 5.4%) and 4.7% (95% CI 3.4% to 5.9%), respectively; after 5 years, the respective increases were 1.8% (95% CI -0.1% to 3.8%), 2.8% (95% CI 0.8% to 4.8%) and 5.4% (95% CI 3.5% to 7.3%). BMD remained above baseline values for 2-3 years in the 1-mg group, 3-4 years in the 2.5-mg group and at least 5 years in the 5-mg group.

INTERPRETATION

The antiresorptive activity of single zoledronate doses of 1-5 mg persist for at least 3 years in postmenopausal women with osteopenia. Clinical trials would be justified to evaluate the effects on fracture risk of less frequent or lower doses of zoledronate than are currently recommended.

TRIAL REGISTRATION

www.anzctr.org.au, no. ACTRN12607000576426.

Bone turnover and periprosthetic bone loss after cementless total hip arthroplasty can be restored by zoledronic acid: a prospective, randomized, open-label, controlled trial

Background

Although the loss of bone mineral density (BMD) after total hip arthroplasty (THA) is a known problem, it remains unresolved. This study prospectively examined the effect of zoledronic acid (ZA) on bone turnover and BMD after cementless THA.

Methods

Between January 2010 and August 2011, 60 patients who underwent cementless THA were randomly assigned to receive either ZA infusion or placebo (0.9% normal saline only) postoperatively. ZA was administered at 2 day and 1 year postoperatively. Periprosthetic BMD in seven Gruen zones was assessed preoperatively and at given time points for 2 years. Serum markers of bone turnover, functional scales, and adverse events were recorded.

Results

Each group contained 27 patients for the final analysis. The loss of BMD across all Gruen zones (significantly in zones 1 and 7) up to 2 years postoperatively was noted in the placebo group. BMD was significantly higher in the ZA group than in the placebo group in Gruen zones 1, 2, 6, and 7 at 1 year and in Gruen zones 1, 6, and 7 at 2 years (p < 0.05). Compared with baseline measures of BMD, the ZA group had increased BMD in zones 1, 2, 4, 5, 6, and 7 at 1 year and in zones 1, 4, 6, and 7 at 2 years (p < 0.05). Serum bone-specific alkaline phosphatase and N-telopeptide of procollagen I levels were significantly increased at 6 weeks in the placebo group and decreased after 3 months in the ZA group. A transient decrease in osteocalcin level was found at 6 months in the ZA group. Functional scales and adverse events were not different between the two groups.

Conclusions

The loss of periprosthetic BMD, especially in the proximal femur (zones 1 and 7), after cementless THA could be effectively reverted using ZA. In addition, bone turnover markers were suppressed until 2 years postoperatively following ZA administration.

Trial registration

Chang Gung Memorial Hospital Protocol Record 98-1150A3, Prevention of Periprosthetic Bone Loss After Total Hip Replacement by Annual Bisphosphonate Therapy, has been reviewed and will be made public on ClinicalTrials.gov. Trial registration number: NCT02838121. Registered on 19 July, 2016.

Risk of Jaw Osteonecrosis After Intravenous Bisphosphonates in Cancer Patients and Patients Without Cancer

OBJECTIVE

To compare the risk of jaw osteonecrosis after intravenous (IV) bisphosphonate administered to patients with cancer vs patients without cancer.

PATIENTS AND METHODS

We conducted a retrospective cohort study of a 5% national sample of Medicare patients administered IV bisphosphonate from January 1, 2008, through December 31, 2013, for cancer vs noncancer indications. Probable jaw osteonecrosis was estimated with an algorithm including diagnoses, surgical procedures, and imaging studies. A non-IV bisphosphonate comparison group included patients prescribed an oral bisphosphonate for 30 days or less.

RESULTS

During follow-up, 40 (0.42%) out of 9482 patients with cancer developed probable jaw osteonecrosis compared with 8 (0.05%) out of 16,046 patients without cancer. In a Cox multivariable survival analysis controlling for patient characteristics and number of IV zoledronic infusions, patients without cancer had a hazard ratio of 0.17 (95% CI, 0.06-0.46) for developing jaw osteonecrosis compared with those with cancer. The lower rate of jaw osteonecrosis in patients without cancer was also confirmed in a number of sensitivity analyses.

CONCLUSION

The low rate of jaw osteonecrosis in patients with osteoporosis who receive IV bisphosphonate should be weighed against the benefit of those agents in preventing hip and other fractures.

GRAND-4: the German retrospective analysis of long-term persistence in women with osteoporosis treated with bisphosphonates or denosumab

This retrospective database study assessed 2-year persistence with bisphosphonates or denosumab in a large German cohort of women with a first-time prescription for osteoporosis treatment. Compared with intravenous or oral bisphosphonates, 2-year persistence was 1.5-2 times higher and risk of discontinuation was significantly lower (P < 0.0001) with denosumab.

INTRODUCTION

Persistence with osteoporosis therapies is critical for fracture risk reduction. Detailed data on long-term persistence (≥2 years) with bisphosphonates and denosumab are sparse.

METHODS

From the German IMS® database, we included women aged 40 years or older with a first-time prescription for bisphosphonates or denosumab between July 2010 and August 2014; patients were followed up until December 2014. The main outcome was treatment discontinuation, with a 60-day permissible gap between filled prescriptions. Two-year persistence was estimated using Kaplan-Meier survival curves, with treatment discontinuation as the failure event. Denosumab was compared with intravenous (i.v.) and oral bisphosphonates separately. Cox proportional hazard ratios (HRs) for the 2-year risk of discontinuation were calculated, with adjustment for age, physician specialty, health insurance status, and previous medication use.

RESULTS

Two-year persistence with denosumab was significantly higher than with i.v. or oral bisphosphonates (39.8 % [n = 21,154] vs 20.9 % [i.v. ibandronate; n = 20,472] and 24.8 % [i.v. zoledronic acid; n = 3966] and 16.7-17.5 % [oral bisphosphonates; n = 114,401]; all P < 0.001). Patients receiving i.v. ibandronate, i.v. zoledronic acid, or oral bisphosphonates had a significantly increased risk of treatment discontinuation than did those receiving denosumab (HR = 1.65, 1.28, and 1.96-2.02, respectively; all P < 0.0001).

CONCLUSIONS

Two-year persistence with denosumab was 1.5-2 times higher than with i.v. or oral bisphosphonates, and risk of discontinuation was significantly lower with denosumab than with bisphosphonates. A more detailed understanding of factors affecting medication-taking behavior may improve persistence and thereby reduce rates of fracture.

Prevalence, pathogenesis, and treatment options for mastocytosis-related osteoporosis

Mastocytosis is a rare condition characterized by abnormal mast cell proliferation and a broad spectrum of manifestations, including various organs and tissues. Osteoporosis is one of the most frequent manifestations of systemic mastocytosis, particularly in adults. Osteoporosis secondary to systemic mastocytosis is a cause of unexplained low bone mineral density that should be investigated when accompanied by suspicious clinical elements. Bone involvement is often complicated by a high recurrence of fragility fractures, mainly vertebral, leading to severe disability. The mechanism of bone loss is the result of different pathways, not yet fully discovered. The main actor is the osteoclast with a relative or absolute predominance of bone resorption. Among the stimuli that drive osteoclast activity, the most important one seems to be the RANK-RANKL signaling, but also histamine and other cytokines play a significant role in the process. The central role of osteoclasts made bisphosphonates, as anti-resorptive drugs, the most rational treatment for bone involvement in systemic mastocytosis. There are a few small studies supporting this approach, with large heterogeneity of drug and administration scheme. Currently, zoledronate has the best evidence in terms of gain in bone mineral density and bone turnover suppression, two surrogate markers of anti-fracture efficacy.

Intravenous zoledronate for osteoporosis: less might be more

Annual administration of 5 mg intravenous zoledronate is moderately effective in reducing fracture risk in older adults, decreasing the relative risk of clinical fracture by 33%. However, almost 10 years after its approval for use in clinical practice there remain very substantial uncertainties about the optimal treatment regimen, that is, the lowest dose and/or longest dosing interval that is efficacious. Several pieces of clinical research suggest that the current recommendation for annual administration of 5 mg zoledronate might represent overtreatment. Clinical trials to clarify the optimal use of zoledronate for reduction of fracture risk should be undertaken.

A Retrospective Longitudinal Database Study of Persistence and Compliance with Treatment of Osteoporosis in Hungary

This study assessed persistence and compliance with anti-osteoporosis therapies, and associations between compliance and clinical outcomes (fracture, fracture-related hospitalization and death), in Hungarian women with postmenopausal osteoporosis. The study used the Hungarian National Health Insurance Fund Administration database and included women with PMO aged at least 50 years, for whom a prescription for anti-osteoporosis medication had been filled between 1 January 2004 and 31 December 2013 (index event). Persistence (prescription refilled within 8 weeks of the end of the previous supply) was evaluated over 2 years; good compliance (medication possession ratio ≥ 80 %) was evaluated at 1 year. Associations between compliance and clinical outcomes (data collected for up to 6 years) were assessed with adjustment for baseline covariates. A total of 296,300 women met the inclusion criteria (524,798 index events). Persistence and compliance were higher for less frequent and parenteral therapies (1- and 2-year persistence: half-yearly [parenteral] vs. daily/weekly/monthly [oral and parenteral], 81 and 38 % vs. 21-34 and 10-18 %, respectively; parenteral vs. oral, 75 and 36 % vs. 32 and 16 %; good compliance: half-yearly vs. daily/weekly/monthly, 70 vs. 24-39 %; parenteral vs. oral 78 vs. 36 %). Good compliance significantly reduced the risks of fracture, fracture-related hospitalization and death (relative risk vs. non-compliance [95 % confidence interval]: 0.77 [0.70-0.84], 0.72 [0.62-0.85] and 0.57 [0.51-0.64], respectively; P < 0.01). Improving compliance through long-interval parenteral therapies may result in clinical benefits for patients.

Management of bone mineral density in HIV-infected patients

INTRODUCTION

Loss of bone mineral density is an emerging problem in persons living with HIV infection. Earlier and more rapid bone demineralization has been attributed not only to the high prevalence of traditional risk factors, but also to specific HIV-related factors. The aim of this guidance is to stimulate an appropriate management of osteoporosis in this population, to identify patients at risk and to better manage them.

AREAS COVERED

Appropriate screening of HIV-infected subjects to identify those at risk for bone fractures is described, as well as the recommended interventions. American and European recommendations in HIV-infected and non-infected populations were considered. As the etiology of bone loss is multifactorial, many factors have to be addressed. Overall, recommendations on traditional risk factors are the same for HIV-infected and non-HIV-infected subjects. However, we should consider some specific factors in the HIV-infected population, including an appropriate antiretroviral therapy in patients with low bone mineral density, and probably novel strategies that could provide an additional benefit, such as anti-inflammatory drugs, although data supporting this approach are scant.

EXPERT OPINION

Some personal opinions are highlighted on the management of bone health in HIV-infected subjects, mainly on the use of FRAX(®) score and DXA scans. In addition, the need to implement new strategies to delay demineralization is remarked upon.

Reference intervals for bone turnover markers in Spanish premenopausal women

The aims of this study were to establish robust reference intervals and to investigate the factors influencing bone turnover markers (BTMs) in healthy premenopausal Spanish women.

A total of 184 women (35–45 years) from 13 centers in Catalonia were analyzed. Blood and second void urine samples were collected between 8 a.m. and 10 a.m. after an overnight fast. Serum procollagen type I amino-terminal propeptide (PINP) and serum cross-linked C-terminal telopeptide of type I collagen (CTX-I) were measured by two automated assays (Roche and IDS), bone alkaline phosphatase (bone ALP) by ELISA, osteocalcin (OC) by IRMA and urinary NTX-I by ELISA. PTH and 25-hydroxyvitamin D (25OHD) levels were measured. All participants completed a questionnaire on lifestyle factors.

Reference intervals were: PINP: 22.7–63.1 and 21.8–65.5 μg/L, bone ALP: 6.0–13.6 μg/L, OC: 8.0–23.0 μg/L, CTX-I: 137–484 and 109–544 ng/L and NTX-I: 19.6–68.9 nM/mM. Oral contraceptive pills (OCPs) influenced PINP (p=0.007), and low body mass index (BMI) was associated with higher BTMs except for bone ALP. Women under 40 had higher median values of most BTMs. CTX-I was influenced by calcium intake (p=0.010) and PTH (p=0.007). 25OHD levels did not influence BTMs. Concordance between the two automated assays for PINP and particularly CTX-I was poor.

Robust reference intervals for BTMs in a Southern European country are provided. The effects of OCPs and BMI on their levels are significant, whilst serum 25OHD levels did not influence BTMs. Age, calcium intake, BMI and PTH influenced CTX-I. The two automated assays for measuring PINP and CTX-I are not interchangeable.