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.

The effects of etidronate on brain calcifications in Fahr's disease or syndrome: rationale and design of the randomised, placebo-controlled, double-blind CALCIFADE trial.

BACKGROUND: Fahr's disease and syndrome are rare disorders leading to calcification of the small arteries in the basal ganglia of the brain, resulting in a wide range of symptoms comprising cognitive decline, movement disorders and neuropsychiatric symptoms. No disease-modifying therapies are available. Studies have shown the potential of treatment of ectopic vascular calcifications with bisphosphonates. This paper describes the rationale and design of the CALCIFADE trial which evaluates the effects of etidronate in patients with Fahr's disease or syndrome. METHODS: The CALCIFADE trial is a randomised, placebo-controlled, double-blind trial which evaluates the effects of etidronate 20 mg/kg during 12 months follow-up in patients aged ≥ 18 years with Fahr's disease or syndrome. Etidronate and placebo will be administered in capsules daily for two weeks on followed by ten weeks off. The study will be conducted at the outpatient clinic of the University Medical Center Utrecht, the Netherlands. The primary endpoint is the change in cognitive functioning after 12 months of treatment. Secondary endpoints are the change in mobility, neuropsychiatric symptoms, volume of brain calcifications, dependence in activities of daily living, and quality of life. RESULTS: Patient recruitment started in April 2023. Results are expected in 2026 and will be disseminated through peer-reviewed journals as well as presentations at national and international conferences. CONCLUSIONS: Fahr's disease and syndrome are slowly progressive disorders with a negative impact on a variety of health outcomes. Etidronate might be a new promising treatment for patients with Fahr's disease or syndrome. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05662111. Registered 22 December 2022, https://clinicaltrials.gov/ct2/show/NCT01585402 .

Novel Treatments for PXE: Targeting the Systemic and Local Drivers of Ectopic Calcification.

Pseudoxanthoma elasticum (PXE) is a heritable multisystem ectopic calcification disorder. The gene responsible for PXE, ABCC6, encodes ABCC6, a hepatic efflux transporter regulating extracellular inorganic pyrophosphate (PPi), a potent endogenous calcification inhibitor. Recent studies demonstrated that in addition to the deficiency of plasma PPi, the activated DDR/PARP signaling in calcified tissues provides an additional possible mechanism of ectopic calcification in PXE. This study examined the effects of etidronate (ETD), a stable PPi analog, and its combination with minocycline (Mino), a potent inhibitor of DDR/PARP, on ectopic calcification in an Abcc6-/- mouse model of PXE. Abcc6-/- mice, at 4 weeks of age, before the development of ectopic calcification, were treated with ETD, Mino, or both for 18 weeks. Micro-computed tomography, histopathologic examination, and quantification of the calcium content in Abcc6-/- mice treated with both ETD and Mino revealed further reduced calcification than either treatment alone. The effects were associated with reduced serum alkaline phosphatase activity without changes in plasma PPi concentrations. These results suggest that ETD and Mino combination therapy might provide an effective therapeutic approach for PXE, a currently intractable disease.

Cost-effectiveness of weekly gastro-resistant risedronate 35 mg, compared with weekly alendronate 70 mg tablets, in the treatment of postmenopausal osteoporosis in Spain.

Aim: To estimate the cost-effectiveness of treating postmenopausal osteoporosis (PMO) with weekly gastro-resistant risedronate 35 mg gastro-resistant tablets (RIS-GR), compared with weekly alendronate 70 mg tablets (ALN) in Spain. Methods: A probabilistic analysis (second-order Monte Carlo simulation) was performed with a time horizon of 5 years, from the perspective of the Spanish National Health System. The bone fracture probabilities were obtained from a cohort study of 3614 women from USA with PMO treated with RIS-GR (1807) or ALN (1807) (Thomasius, 2022). The pharmacological cost and the cost of fractures were obtained from Spanish sources (€ 2022). The utilities of patients with and without fracture (quality-adjusted life years [QALYs]) were obtained from the medical literature. Results: Compared with ALN, treatment with RIS-GR can avoid 79 fractures (between 75 and 82) every 1000 patients treated, and 0.0119 QALYs would be gained (between 0.0098 and 0.0140) per patient. Additionally, GR-RIS would generate a cost saving per patient of €1994 (€1437-2904) with a probability of 99.7%. The scenario analyses confirmed the stability of the base case results. Conclusion: According to this study, RIS-GR would be the dominant treatment (lower costs with QALY gain) compared with ALN.

Fracture risk in women with osteoporosis initiated on gastro-resistant risedronate versus immediate release risedronate or alendronate: a claims data analysis in the USA.

The study results indicate that women with osteoporosis initiated on gastro-resistant risedronate have a lower risk of fracture than those initiated on immediate release risedronate or alendronate. A large proportion of women discontinued all oral bisphosphonate therapies within 1 year of treatment start. PURPOSE: Using a US claims database (2009-2019), we compared risk of fractures between women with osteoporosis initiated on gastro-resistant (GR) risedronate and those initiated on (a) immediate release (IR) risedronate or (b) immediate release alendronate. METHODS: Women aged ≥ 60 years with osteoporosis who had ≥ 2 oral bisphosphonate prescription fills were followed for ≥ 1 year after the first observed bisphosphonates dispensing (index date). Fracture risk was compared between the GR risedronate and IR risedronate/alendronate cohorts using adjusted incidence rate ratios (aIRRs), both overall and in subgroups with high fracture risk due to older age or comorbidity/medications. Site-specific fractures were identified based on diagnosis codes recorded on medical claims using a claims-based algorithm. Persistence on bisphosphonate therapy was evaluated for all groups. RESULTS: aIRRs generally indicated lower fracture risk for GR risedronate than IR risedronate and alendronate. When comparing GR risedronate to IR risedronate, statistically significant aIRRs (p < 0.05) were observed for pelvic fractures in the full cohorts (aIRRs = 0.37), for any fracture and pelvic fractures among women aged ≥ 65 years (aIRRs = 0.63 and 0.41), for any fracture and pelvic fractures among women aged ≥ 70 years (aIRRs = 0.69 and 0.24), and for pelvic fracture among high-risk women due to comorbidity/medications (aIRR = 0.34). When comparing GR risedronate to alendronate, statistically significant aIRRs were observed for pelvic fractures in the full cohorts (aIRR = 0.54), for any fracture and wrist/arm fractures among women aged ≥ 65 years (aIRRs = 0.73 and 0.63), and for any fracture, pelvic, and wrist/arm fractures among women aged ≥ 70 years (aIRRs = 0.72, 0.36, and 0.58). In all cohorts, ~ 40% completely discontinued oral bisphosphonates within 1 year. CONCLUSIONS: Discontinuation rates of oral bisphosphonate therapy were high. However, women initiated on GR risedronate had a significantly lower risk of fracture for several skeletal sites than women initiated on IR risedronate/alendronate, particularly those aged ≥ 70 years.

Beyond Antiresorptive Activity: Risedronate-Based Coordination Complexes To Potentially Treat Osteolytic Metastases.

Coordination of clinically employed bisphosphonate, risedronate (RISE), to bioactive metals, Ca2+, Mg2+, and Zn2+, allowed the formation of bisphosphonate-based coordination complexes (BPCCs). Three RISE-based BPCCs, RISE-Ca, RISE-Mg, and RISE-Zn, were produced, and their structures were elucidated by single crystal X-ray diffraction. Interestingly, the addition of an auxiliary ligand, etidronic acid (HEDP), resulted in the recrystallized protonated form of the ligand, H-RISE. The pH-dependent structural stability of the RISE-based BPCCs was measured by means of dissolution profiles under neutral and acidic simulated physiological conditions (PBS and FaSSGF, respectively). In comparison to RISE (Actonel), the complexes showed a lower equilibrium solubility (∼70-85% in 18-24 h) in PBS, while a higher equilibrium solubility (∼100% in 3 h) in acidic media. The results point to the capacity to release this BP in a pH-dependent manner from the RISE-based BPCCs. Subsequently, the particle size of RISE-Ca was reduced, from 300 µm to ∼350 d.nm, employing the phase inversion temperature (PIT)-nanoemulsion method, resulting in nano-Ca@RISE. Aggregation measurements of nano-Ca@RISE in 1% fetal bovine serum (FBS):H2O was monitored after 24, 48, and 72 h to study the particle size longevity in physiological media, showing that the suspended material has the potential to maintain its particle size over time. Furthermore, binding assays were performed to determine the potential binding of nano-Ca@RISE to the bone, where results show higher binding (∼1.7×) for the material to hydroxyapatite (HA, 30%) when compared to RISE (17%) in 1 d. The cytotoxicity effects of nano-Ca@RISE were compared to those of RISE against the human breast cancer MDA-MB-231 and normal osteoblast-like hFOB 1.19 cell lines by dose-response curves and relative cell viability assays in an in vitro setting. The results demonstrate that nano-Ca@RISE significantly decreases the viability of MDA-MB-231 with high specificity, at concentrations ∼2-3× lower than the ones reported employing other third-generation BPs. This is supported by the fact that when normal osteoblast cells (hFOB 1.19), which are part of the tissue microenvironment at metastatic sites, were treated with nano-Ca@RISE no significant decrease in viability was observed. This study expands on the therapeutic potential of RISE beyond its antiresorptive activity through the design of BPCCs, specifically nano-Ca@RISE, that bind to the bone and degrade in a pH-dependent manner under acidic conditions.

Real-Time Impedance-Based Monitoring of the Growth and Inhibition of Osteomyelitis Biofilm Pathogen Staphylococcus aureus Treated with Novel Bisphosphonate-Fluoroquinolone Antimicrobial Conjugates.

Osteomyelitis is a limb- and life-threatening orthopedic infection predominantly caused by Staphylococcus aureus biofilms. Bone infections are extremely challenging to treat clinically. Therefore, we have been designing, synthesizing, and testing novel antibiotic conjugates to target bone infections. This class of conjugates comprises bone-binding bisphosphonates as biochemical vectors for the delivery of antibiotic agents to bone minerals (hydroxyapatite). In the present study, we utilized a real-time impedance-based assay to study the growth of Staphylococcus aureus biofilms over time and to test the antimicrobial efficacy of our novel conjugates on the inhibition of biofilm growth in the presence and absence of hydroxyapatite. We tested early and newer generation quinolone antibiotics (ciprofloxacin, moxifloxacin, sitafloxacin, and nemonoxacin) and several bisphosphonate-conjugated versions of these antibiotics (bisphosphonate-carbamate-sitafloxacin (BCS), bisphosphonate-carbamate-nemonoxacin (BCN), etidronate-carbamate-ciprofloxacin (ECC), and etidronate-carbamate-moxifloxacin (ECX)) and found that they were able to inhibit Staphylococcus aureus biofilms in a dose-dependent manner. Among the conjugates, the greatest antimicrobial efficacy was observed for BCN with an MIC of 1.48 µg/mL. The conjugates demonstrated varying antimicrobial activity depending on the specific antibiotic used for conjugation, the type of bisphosphonate moiety, the chemical conjugation scheme, and the presence or absence of hydroxyapatite. The conjugates designed and tested in this study retained the bone-binding properties of the parent bisphosphonate moiety as confirmed using high-performance liquid chromatography. They also retained the antimicrobial activity of the parent antibiotic in the presence or absence of hydroxyapatite, albeit at lower levels due to the nature of their chemical modification. These findings will aid in the optimization and testing of this novel class of drugs for future applications to pharmacotherapy in osteomyelitis.

Impact of agitation/activation strategies on the antibiofilm potential of sodium hypochlorite/etidronate mixture in vitro.

BACKGROUND: To investigate the effect of a rotary agitation method or ultrasonically activated irrigation on the antibiofilm effect of a mixture of sodium hypochlorite (NaOCl) and etidronate (1-hydroxyethylidene-1,1-bisphosphonate, HEBP) using a dual-species biofilm model in root canal system. METHODS: Mature dual-species biofilms of Enterococcus faecalis and Streptococcus gordonii were formed in root canals of mandibular premolars. Teeth were randomly allotted (n = 12) to group 1, XP-endo Finisher (XPF); group 2, ultrasonically activated irrigation (UAI); group 3, syringe-and-needle irrigation (SNI). In all groups, canals were instrumented with a rotary instrument (XP-endo Shaper) prior to irrigant agitation/activation. A mixture containing 2.5% NaOCl and 9% HEBP was used throughout the experiment. Bacterial counts from the canal were determined using qPCR before preparation (S1), after preparation (S2), and after final irrigation agitation/activation (S3). Bacterial viability within the dentinal tubules in the coronal, middle and apical root-thirds was quantified using confocal microscopy after Live/Dead staining. The bacterial counts and viability were compared between groups using one-way ANOVA and post-hoc Tukey's tests. Paired t-test was used to compare the bacterial counts within groups. RESULTS: Instrumentation alone could significantly reduce the microbial counts in all the groups (P < 0.0001). Subsequent agitation/activation resulted in significant microbial reduction only in XPF and UAI (P < 0.05), both of which reduced significantly more microbial counts than SNI (P < 0.05). Live/Dead staining revealed that XPF and UAI showed significantly greater percentage of dead bacteria within the dentinal tubules than SNI in the coronal third (P < 0.05); UAI resulted in the significantly highest percentage of dead bacteria in the middle third (P < 0.05); while there was no significant difference between the groups in the apical third (P > 0.05). CONCLUSIONS: When using the sodium hypochlorite/etidronate mixture for irrigation, final irrigant agitation/activation with XP-endo Finisher or ultrasonic can improve disinfection of the main root canal space and the dentinal tubules in the coronal third, while ultrasonically activated irrigation appears to exhibit better disinfection within dentinal tubules in the middle third.

A Systematic Review of the Effectiveness of Bisphosphonates for Otosclerosis.

OBJECTIVE: To systematically review the evidence for the use of bisphosphonate therapy in otosclerosis through clinically relevant outcomes. DATABASES REVIEWED: MEDLINE, EMBASE, PubMed, and CINAHL databases were searched up to July 12, 2021. METHODS: RCTs and cohort studies investigating the effect of bisphosphate therapy on adults or children diagnosed with otosclerosis were included. The risk of bias within trials was examined using the ROB2 tool for RCTs, and the ROBINS-I for non-RCTs. RESULTS: Three studies reported over five publications were included in the systematic review. Data from one RCT at 6 months did not demonstrate any improvement nor deterioration in audiological outcomes in participants treated with Sodium Alendronate. Data from MRI in this group demonstrated improvements in the SI of the otosclerotic foci at the RAOW compared to participants taking placebo. In another RCT, improvements in audiological outcomes were seen at 12 and 24 months in individuals treated with Etidronate Sodium. Long-term data from a retrospective cohort study demonstrated stabilisation of hearing in individuals with otosclerosis and progressive SNHL. CONCLUSION: There is insufficient evidence to recommend the routine use of bisphosphonates in otosclerosis patients at present. Long-term retrospective data has suggested a role for bisphosphonates in the subset of patients with deteriorating sensorineural hearing loss with the aim of hearing stabilisation. Adequately powered RCTs with long term follow up will be required to evaluate this further.

Treatment of Temporomandibular Joint Heterotopic Ossification: A Novel Protocol With Multimodal Therapy Based on Literature Review and Presentation of a Unique Case Report.

PURPOSE: The purpose of this study was to create a treatment protocol for cases of heterotopic ossification (HO) of the temporomandibular joint (TMJ), particularly those refractory to current TMJ HO protocols. In addition, we demonstrate the success of this protocol on a unique case of recurrent HO that failed multiple TMJ HO protocols in the setting of an improvised explosive device (IED) blast in a wounded warrior. METHODS: An electronic literature review was conducted via PubMed and Web of Science. Twenty-five studies were identified to provide supporting evidence for a proposed, up-to-date protocol for the treatment of refractory TMJ HO. The authors present a case report of a wounded warrior with HO ankylosis of bilateral TMJs in the setting of IED blast and demonstrate successful use of our surgical and pharmacotherapeutic protocol. RESULTS: Based on the literature review, our proposed protocol consists of pharmacotherapy with celecoxib and etidronate, with weekly forced dilation (brisement) and home physical therapy with the TheraBite Jaw Motion Rehab System. Surgically, the TMJ should be treated with two-stage reconstruction using initial polymethyl methacrylate spacers and subsequent total joint replacement with custom prostheses, fat grafting, and 3-dimensional-navigated total resection of HO. This protocol was successfully utilized in our patient's refractory HO ankylosed TMJ secondary to IED blast, and the patient's maximal incisal opening was regained and has remained stable 2 years after surgery without recurrent HO. CONCLUSIONS: Our method for treatment in this case deviated from the standard TMJ Concepts HO protocol in that it included multimodal pharmacotherapy with celecoxib and etidronate. Based on our literature review and experience, we advise that clinicians utilize our protocol for the management of all craniofacial HO cases, particularly in cases of recurrent HO that fail conventional therapies and/or involving high-order blast trauma.

Bone-loading exercises versus risedronate for the prevention of osteoporosis in postmenopausal women with low bone mass: a randomized controlled trial.

PURPOSE: This randomized controlled trial compared changes in bone mineral density (BMD) and bone turnover in postmenopausal women with low bone mass randomized to 12 months of either risedronate, exercise, or a control group. METHODS: Two hundred seventy-six women with low bone mass, within 6 years of menopause, were included in analysis. Treatment groups were 12 months of (a) calcium and vitamin D supplements (CaD) (control), (b) risedronate + CaD (risedronate), or (c) bone-loading exercises + CaD (exercise). BMD and serum markers for bone formation (Alkphase B) and resorption (Serum Ntx) were analyzed at baseline, 6, and 12 months. RESULTS: Using hierarchical linear modeling, a group by time interaction was found for BMD at the spine, indicating a greater improvement in the risedronate group compared to exercise (p ≤ .010) or control groups (p ≤ .001). At 12 months, for women prescribed risedronate, changes in BMD at the spine, hip, and femoral neck from baseline were + 1.9%, + 0.9%, and + .09%; in exercise group women, + 0.2%, + 0.5%, and - 0.4%; and in control group women, - 0.7%, + 0.5%, and - 0.5%. There were also significant differences in reductions in Alkphase B (RvsE, p < .001, RvsC, p < .001) and Serum Ntx (RvsE, p = .004, RvsC, p = .007) in risedronate women compared to exercise and control groups. For risedronate, 12-month changes in Alkphase B and Serum Ntx were - 20.3% and - 19.0%; for exercise, - 6.7% and - 7.0%; and for control, - 6.3% and - 9.0%. CONCLUSION: Postmenopausal women with low bone mass should obtain adequate calcium and vitamin D and participate in bone-loading exercises. Additional use of BPs will increase BMD, especially at the spine.

Comparing the Efficacies of Bisphosphonates' Therapies for Osteoporosis Persistence and Compliance: A Systematic Review.

OBJECTIVES: Osteoporosis is the most prevalent metabolic bone disorder worldwide. This review was undertaken to compare the efficacies of bisphosphonates therapies for patient persistence and compliance for the treatment of osteoporosis. METHODS: A systematic review was performed in accordance with the available reporting items. MEDLINE and Cochrane library databases were applied for literature searched up to January 2020. All major studies such as prospective, retrospective and review articles that examined patient persistence or compliance to bisphosphonates for osteoporosis were included. RESULTS: The literature search found 656 relevant published reports, out of which 87 were included. The 10, 712, 176 osteoporotic patients were studied for patient persistence and 5, 875, 718 patients were studied for patient compliances. Analysis of all studied bisphosphonates showed almost similar patterns for patient persistence rates as it was decreased over the time following initial prescription, but persistence length was found to be significantly higher for alendronate therapy as compared to the other studied bisphosphonates (p<0.001), whereas the length of persistence of all other bisphosphonates (other than alendronate) were almost same (p>0.05). Analysis of patient compliances with etidronate therapy showed the highest percent medication possession ratio (MRP) at 12 months, followed by the MRPs of ibandronate, alendronate, risedronate, and clodronate. CONCLUSION: This is the first systematic review that shows the comparison of the efficiencies of bisphosphonates for patient persistence and compliance for the treatment of osteoporosis. The data showed that the length of patient persistence was highest for alendronate therapy, whereas patient compliance was highest for etidronate therapy for the treatment of osteoporosis.

Fracture rates and economic outcomes in patients with osteoporosis prescribed risedronate gastro-resistant versus other oral bisphosphonates: a claims data analysis.

Patients with osteoporosis prescribed risedronate gastro-resistant had a lower incidence of fractures versus those prescribed other oral bisphosphonates. Administration of risedronate gastric-resistant does not require fasting, and this more convenient dosing administration may explain its improved efficacy. PURPOSE: Up to half of patients do not follow complex dosing instructions of immediate-release bisphosphonates used for the prevention of osteoporotic fractures, which can result in suboptimal effectiveness. Risedronate gastro-resistant (GR) offers a more convenient dosing option by eliminating the need for fasting. This study compares fracture rates and outcomes between osteoporosis women treated with risedronate GR (GR cohort) versus other oral bisphosphonates (other cohort). METHODS: Claims from women with osteoporosis in the USA were analyzed. Patients were classified into the two cohorts based on the first oral bisphosphonate observed (index date) and matched 1:1 based on patient characteristics. Patients were observed for ≥ 2 years following the index date. Fracture rates, health care resource utilization and costs, and treatment persistence were compared. RESULTS: In total, 2,726 patients were selected in each cohort (median age: 60.0 years). The incidence of fractures was lower in the GR versus the other cohort for any fracture sites (incidence rate ratio, 95% CI: 0.83, 0.70-0.97) and spine fractures (0.71, 0.54-0.95), although the respective rate of medication discontinuation at 2 years was 80.5% and 74.4%. Time to first fracture was delayed for the GR cohort, reaching statistical significance after 36 months. The GR cohort incurred fewer hospitalizations (incidence rate per 1,000 patient-years: GR = 106.74; other = 124.20, p < 0.05) translating into lower hospitalization costs per patient per year (GR = $3,611; other = $4,603, p < 0.05). CONCLUSIONS: Patients prescribed risedronate GR versus other bisphosphonates had a lower incidence of fractures, which may be explained by the fact that the GR formulation is absorbed even when taken with food.

Case report: Osteomalacia due to bisphosphonate treatment in a patient on hemodialysis.

BACKGROUND: No publications have reported on osteomalacia in patients receiving intermittent cyclical therapy with etidronate (a bisphosphonate) and undergoing long-term hemodialysis (HD). CASE PRESENTATION: We report on a 46-year-old Japanese man admitted to our hospital for further examination of left forearm pain. Maintenance HD was started at age 24 years, and the man had been on HD since then. At age 38 years, surgical parathyroidectomy was performed for secondary hyperparathyroidism; iliac crest bone biopsy performed at the same time showed osteitis fibrosa. The active vitamin D3 preparation calcitriol was started, and intermittent cyclical etidronate therapy was introduced 2 years later for osteoporosis. At age 45 years, the patient stopped taking calcitriol because of hypercalcemia but continued with etidronate. At age 46 years, a pseudofracture with a Looser zone occurred in the left ulna, and left femur bone biopsy revealed osteomalacia. Etidronate was discontinued, and calcitriol was restarted; open reduction and internal fixation with an angular stability plate were performed. Union of the bone was achieved 10 months after the operation. At age 49 years, a lumber bone biopsy confirmed improved bone morphometry. CONCLUSIONS: We believe that intermittent cyclical etidronate therapy without administration of active vitamin D3 during long-term HD might have induced osteomalacia, resulting in the ulna insufficiency fracture. Therefore, we propose that administration of active vitamin D3 is essential to prevent osteomalacia in patients on long-term HD who are receiving bisphosphonates and have potential vitamin D3 deficiency.

Icariin reduces bone loss in a Rankl-induced transgenic medaka (Oryzias latipes) model for osteoporosis.

Given the limitations and side effects of many synthetic drugs, natural products are an important alternative source for drugs and medications for many diseases. Icariin (ICA), one of the main flavonoids from plants of the Epimedium genus, has been shown to ameliorate osteoporosis and improve bone health in preclinical studies. Those studies have used different in vivo models, mostly rodents, but the underlying mechanisms remain unclear. The present study shows, for the first time, that ICA reduces bone damage in a Rankl-induced medaka fish (Oryzias latipes), a non-rodent osteoporosis model. Live imaging was previously performed in this model to characterize antiresorptive and bone-anabolic properties of drugs. Here, a new quantification method (IM ) was established based on the length of mineralized neural arches to quantify levels of bone mineralization damage and protection in early post-embryonic fish. This method was validated by quantification of three levels of bone damage in three independent Rankl fish lines, and by the determination of different degrees of severity of osteoporosis-like phenotypes in one Rankl line exposed to variable Rankl induction schemes. IM was also used to quantify the efficacy of alendronate and etidronate, two common anti-osteoporotic bisphosphonates, and revealed comparable bone protective effects for ICA and alendronate in this fish osteoporosis model. This study's data support the value of the medaka fish model for bone research and establish a method to screen for novel osteoprotective compounds.

Bisphosphonates or RANK-ligand-inhibitors for men with prostate cancer and bone metastases: a network meta-analysis.

BACKGROUND: Different bone-modifying agents like bisphosphonates and receptor activator of nuclear factor-kappa B ligand (RANKL)-inhibitors are used as supportive treatment in men with prostate cancer and bone metastases to prevent skeletal-related events (SREs). SREs such as pathologic fractures, spinal cord compression, surgery and radiotherapy to the bone, and hypercalcemia lead to morbidity, a poor performance status, and impaired quality of life. Efficacy and acceptability of the bone-targeted therapy is therefore of high relevance. Until now recommendations in guidelines on which bone-modifying agents should be used are rare and inconsistent. OBJECTIVES: To assess the effects of bisphosphonates and RANKL-inhibitors as supportive treatment for prostate cancer patients with bone metastases and to generate a clinically meaningful treatment ranking according to their safety and efficacy using network meta-analysis. SEARCH METHODS: We identified studies by electronically searching the bibliographic databases Cochrane Controlled Register of Trials (CENTRAL), MEDLINE, and Embase until 23 March 2020. We searched the Cochrane Library and various trial registries and screened abstracts of conference proceedings and reference lists of identified trials. SELECTION CRITERIA: We included randomized controlled trials comparing different bisphosphonates and RANKL-inihibitors with each other or against no further treatment or placebo for men with prostate cancer and bone metastases. We included men with castration-restrictive and castration-sensitive prostate cancer and conducted subgroup analyses according to this criteria. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed the quality of trials. We defined proportion of participants with pain response and the adverse events renal impairment and osteonecrosis of the jaw (ONJ) as the primary outcomes. Secondary outcomes were SREs in total and each separately (see above), mortality, quality of life, and further adverse events such as grade 3 to 4 adverse events, hypocalcemia, fatigue, diarrhea, and nausea. We conducted network meta-analysis and generated treatment rankings for all outcomes, except quality of life due to insufficient reporting on this outcome. We compiled ranking plots to compare single outcomes of efficacy against outcomes of acceptability of the bone-modifying agents. We assessed the certainty of the evidence for the main outcomes using the GRADE approach. MAIN RESULTS: Twenty-five trials fulfilled our inclusion criteria. Twenty-one trials could be considered in the quantitative analysis, of which six bisphosphonates (zoledronic acid, risedronate, pamidronate, alendronate, etidronate, or clodronate) were compared with each other, the RANKL-inhibitor denosumab, or no treatment/placebo. By conducting network meta-analysis we were able to compare all of these reported agents directly and/or indirectly within the network for each outcome. In the abstract only the comparisons of zoledronic acid and denosumab against the main comparator (no treatment/placebo) are described for outcomes that were predefined as most relevant and that also appear in the 'Summary of findings' table. Other results, as well as results of subgroup analyses regarding castration status of participants, are displayed in the Results section of the full text. Treatment with zoledronic acid probably neither reduces nor increases the proportion of participants with pain response when compared to no treatment/placebo (risk ratio (RR) 1.46, 95% confidence interval (CI) 0.93 to 2.32; per 1000 participants 121 more (19 less to 349 more); moderate-certainty evidence; network based on 4 trials including 1013 participants). For this outcome none of the trials reported results for the comparison with denosumab. The adverse event renal impairment probably occurs more often when treated with zoledronic acid compared to treatment/placebo (RR 1.63, 95% CI 1.08 to 2.45; per 1000 participants 78 more (10 more to 180 more); moderate-certainty evidence; network based on 6 trials including 1769 participants). Results for denosumab could not be included for this outcome, since zero events cannot be considered in the network meta-analysis, therefore it does not appear in the ranking. Treatment with denosumab results in increased occurrence of the adverse event ONJ (RR 3.45, 95% CI 1.06 to 11.24; per 1000 participants 30 more (1 more to 125 more); high-certainty evidence; 4 trials, 3006 participants) compared to no treatment/placebo. When comparing zoledronic acid to no treatment/placebo, the confidence intervals include the possibility of benefit or harm, therefore treatment with zoledronic acid probably neither reduces nor increases ONJ (RR 1.88, 95% CI 0.73 to 4.87; per 1000 participants 11 more (3 less to 47 more); moderate-certainty evidence; network based on 4 trials including 3006 participants). Compared to no treatment/placebo, treatment with zoledronic acid (RR 0.84, 95% CI 0.72 to 0.97) and denosumab (RR 0.72, 95% CI 0.54 to 0.96) may result in a reduction of the total number of SREs (per 1000 participants 75 fewer (131 fewer to 14 fewer) and 131 fewer (215 fewer to 19 fewer); both low-certainty evidence; 12 trials, 5240 participants). Treatment with zoledronic acid and denosumab likely neither reduces nor increases mortality when compared to no treatment/placebo (zoledronic acid RR 0.90, 95% CI 0.80 to 1.01; per 1000 participants 48 fewer (97 fewer to 5 more); denosumab RR 0.93, 95% CI 0.77 to 1.11; per 1000 participants 34 fewer (111 fewer to 54 more); both moderate-certainty evidence; 13 trials, 5494 participants). Due to insufficient reporting, no network meta-analysis was possible for the outcome quality of life. One study with 1904 participants comparing zoledronic acid and denosumab showed that more zoledronic acid-treated participants than denosumab-treated participants experienced a greater than or equal to five-point decrease in Functional Assessment of Cancer Therapy-General total scores over a range of 18 months (average relative difference = 6.8%, range -9.4% to 14.6%) or worsening of cancer-related quality of life. AUTHORS' CONCLUSIONS: When considering bone-modifying agents as supportive treatment, one has to balance between efficacy and acceptability. Results suggest that Zoledronic acid likely increases both the proportion of participants with pain response, and the proportion of participants experiencing adverse events However, more trials with head-to-head comparisons including all potential agents are needed to draw the whole picture and proof the results of this analysis.

History of risedronate.

Herein we review the discovery, development, commercial history and legacy of risedronate or NE-58095, a potent N-containing bisphosphonate developed by scientists at the Cincinnati Miami Valley Laboratories and the Norwich Eaton Laboratories of Procter and Gamble. It is characterized by a hydroxyl substituent (R1) and a pyridyl-methylene substituent (R2) at the carbon bridging two phosphonate moieties. It was shown to have greater potency than alendronate in cell-based systems while binding affinity to bone matrix was lower than alendronate, accounting for the relatively rapid offset of bone turnover inhibition when therapy is discontinued. Risedronate was shown to significantly reduce serum alkaline phosphatase and clinical features in patients with Paget's disease and was approved for this indication, at a dose of 30 mg daily for 2 months, in 1998. Formal dose response testing for treatment of osteoporosis was not performed. In large Phase 3 studies, 5 mg risedronate daily increased bone mineral density more than did the 2.5 mg dose. As a result, the 2.5 mg dose was dropped from most of the Phase 3 studies after 12 months. The 5 mg daily dose was approved for treating and preventing postmenopausal osteoporosis and glucocorticoid-induced osteoporosis in 2000. The drug was subsequently approved for treating men with osteoporosis. Following the leads of other companies, weekly and monthly preparations were developed and approved, based on non-inferiority BMD studies vs the 5 mg daily oral dose as was a unique dosing regimen of 75 mg given on 2 consecutive days each month. Finally, to overcome the effect of food on limiting the already poor gastrointestinal absorption of the drug, a once-weekly oral preparation containing the chelating agent EDTA and with an enteric coating delaying dissolution until the tablet was in the small intestine was approved in 2010 to be administered after breakfast. The Alliance for Better Bone Health, a collaboration between Procter & Gamble Pharmaceuticals and sanofi-aventis U.S. was formed to market risedronate as Actonel® and, subsequently, Actonel-EC® or Atelvia®. These drugs are still marketed by sanofi-aventis in some countries. The sale of the pharmaceutical division of Procter & Gamble to Warner Chilcott (US) was based, in large part, on the perceived value and marketability of the risedronate drugs. When marketing targets of Warner-Chilcott were not met, the rights of risedronate were sold to Allergan USA, Inc. which never actively promoted the drug. Generic forms of risedronate were introduced into the United States in 2015 but are rarely used, although several generic forms are actively marketed in other countries.

[Basic Studies on the Mechanism, Prevention, and Treatment of Osteonecrosis of the Jaw Induced by Bisphosphonates].

Since the first report in 2003, bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been increasing, without effective clinical strategies. Osteoporosis is common in elderly women, and bisphosphonates (BPs) are typical and widely used anti-osteoporotic or anti-bone-resorptive drugs. BRONJ is now a serious concern in dentistry. As BPs are pyrophosphate analogues and bind strongly to bone hydroxyapatite, and the P-C-P structure of BPs is non-hydrolysable, they accumulate in bones upon repeated administration. During bone-resorption, BPs are taken into osteoclasts and exhibit cytotoxicity, producing a long-lasting anti-bone-resorptive effect. BPs are divided into nitrogen-containing BPs (N-BPs) and non-nitrogen-containing BPs (non-N-BPs). N-BPs have far stronger anti-bone-resorptive effects than non-N-BPs, and BRONJ is caused by N-BPs. Our murine experiments have revealed the following. N-BPs, but not non-N-BPs, exhibit direct and potent inflammatory/necrotic effects on soft-tissues. These effects are augmented by lipopolysaccharide (the inflammatory component of bacterial cell-walls) and the accumulation of N-BPs in jawbones is augmented by inflammation. N-BPs are taken into soft-tissue cells via phosphate-transporters, while the non-N-BPs etidronate and clodronate inhibit this transportation. Etidronate, but not clodronate, has the effect of expelling N-BPs that have accumulated in bones. Moreover, etidronate and clodronate each have an analgesic effect, while clodronate has an anti-inflammatory effect via inhibition of phosphate-transporters. These findings suggest that BRONJ may be induced by phosphate-transporter-mediated and infection-promoted mechanisms, and that etidronate and clodronate may be useful for preventing and treating BRONJ. Our clinical trials support etidronate being useful for treating BRONJ, although additional clinical trials of etidronate and clodronate are needed.

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.