Efficacy of bisphosphonates in detection of early enamel caries using NIR fluorescence imaging and inhibition of caries progression.

NIR fluorescence imaging using bisphosphonate-Indocyanine green has been indicated for early interproximal caries detection. This study assessed diagnostic accuracy of caries detection by NIR fluorescence imaging with OsteoSense 750® (OS750) in vitro and ex vivo, and to analyze the therapeutic efficacy of a bisphosphonate (Etidronate) in inhibiting enamel caries progression in vitro. Methods: Four experiments were conducted using extracted human teeth; 1) to calculate the infiltration rate of OS750 into interproximal white spot lesions using fluorescence microscope, 2) to assess diagnostic accuracy of interproximal natural white spot lesions using desktop NIR fluorescence imaging device in vitro setting, 3) to assess diagnostic accuracy of artificially created deeper enamel carious lesion (0.5 mm~1.0 mm) using NIR fluorescence image through the head-mount display in ex vivo setting, 4) to compare the progression on the enamel caries lesions treated by Etidronate, NaF and distilled-water. Diagnostic accuracy was analyzed using sensitivity, specificity and receiver operating curves (ROC). The caries progression was calculated with micro-CT and was statistically analyzed using a two-way ANOVA and the Tukey HDS post-hoc test. Results: 1) The infiltration rate of OS750 was 101.83% ± 8.66 (Min: 90.10%, Max: 133.94%). 2) The average of sensitivity and specificity in vitro setting experiments were 86.7% ± 4.4% and 70% ± 11%, respectively. The average of area under the ROC curves (AUC) was 0.883 ± 0.059 indicating excellent performance. 3) The mean sensitivity and specificity in ex vivo setting was 82.97% ± 15% and 76.78% ± 13.27% respectively. 4) The carious lesion volume treated by Etidronate was significantly smaller at post treatment-1 (p<0.05) and treatment-2 (p<0.01) than the control. There was no significant difference in lesion volume in the Etidronate and NaF group at the time point of post treatment-1. Conclusion: This study suggests that bisphosphonates contribute to both early diagnosis of enamel caries and inhibition of caries progression.

The effect of etidronate on choroidal neovascular activity in patients with pseudoxanthoma elasticum.

AIM: To assess the effect of the bisphosphonate etidronate on choroidal neovascular (CNV) activity in patients with pseudoxanthoma elasticum (PXE). METHODS: This is an ancillary study in a single center, randomized, double-blind placebo-controlled trial (RCT) in which 74 patients with PXE were assigned to either one-year etidronate or placebo treatment. Spectral domain optical coherence tomography (SD-OCT) imaging and color fundus photography were performed every three months for one year and were systematically assessed on signs of CNV activity. RESULTS: In the etidronate group, 11 (30%) of the patients had CNV activity at baseline, compared to 25 (67%) of the patients in the placebo group (P = 0.005). The proportion of eyes with CNV activity during the study ranged from 18-33% in the etidronate group and 42-56% in the placebo group and no significant difference in improvement or worsening of CNV activity was found (P = 0.168). Using a generalized mixed model for repeated measures, there was a protective effect of etidronate in crude analysis (RR 0.86, 95% CI 0.75-0.98) that disappeared when adjusting for baseline CNV activity (RR 0.97, 95% CI 0.84-1.13). CONCLUSION: In this post-hoc RCT analysis we did not observe a protecting or deteriorating effect of etidronate on CNV activity in patients with PXE after adjustment for baseline CNV.

Qualitative analysis of smear layer treated with different etidronate concentrations: A scanning electron microscopy study.

The aim of this study was to examine the smear layer removal capacity of various etidronate treatments. Seventy-eight roots were instrumented up to apical size X4 and randomly divided into five treatment groups and a positive control group (n = 13). Groups were as follows: irrigation with 5 ml of sterile saline (control) for 3 min, 5 ml of 17% ethylenediaminetetraacetic acid (EDTA) for 3 min, 5 ml of 9% A1-hydroxyethylidene-1,1-bisphosphonate (HEBP) for 3 min, 5 ml of 18% HEBP for 3 min, irrigation with 5 ml of 1% sodium hypochlorite (NaOCl) + 9% HEBP for 3 min, and 5 ml of 2% NaOCl + 18% HEBP for 3 min. The roots were examined using a scanning electron microscope. The smear layer scores in the 2% NaOCl + 18% HEBP group were lower than those in the other treatment groups and the control group (p < .05). There were no significant differences among the treatment groups in the smear layer scores of the coronal and middle thirds. However, the smear layer scores in the 2% NaOCl + 18% HEBP treatment group were lower those in the 9% HEBP and 18% HEBP treatment groups in the apical third (p < .05). In the clinical setting, the recommended concentration of HEBP is 18%, and it should be used with an oxidizing agent to ensure optimum smear layer removal.

Bisphosphosphonate-calcium phosphate cement composite and its properties.

Calcium phosphate cement (CPC) has been studied extensively due to its bioactivity and biodegradability. CPC is typically made by a combination of multiple calcium phosphates that form a paste that sets and hardens in the body after being combined with either water or an aqueous solution. It is highly moldable and easily manipulated, and CPCs possess osteoconductive properties. Due to these characteristics, CPCs offer great promise in bone grafting applications. CPC combined with drugs has a great potential as drug delivery system and has been studied extensively. In this review we have focused on Bisphosphonate-CPC drug delivery system. In addition, we introduce and discuss the potential of studying other bisphosphonates.

Influence of dentine debris and organic tissue on the properties of sodium hypochlorite solutions.

AIM: To determine the free available chlorine of 2.5% sodium hypochlorite (NaOCl) alone and combined with 9% etidronic acid (HEDP) in the presence of inhibitors, organic tissue and organic tissue plus dentine debris; to evaluate the influence of dentine debris on the tissue-dissolving capacity of both NaOCl solutions; and to determine the antimicrobial action of these solutions when in contact with organic tissue and organic tissue plus dentine debris. METHODOLOGY: The available chlorine of the solutions over time in the absence and presence of the inhibitors was measured using a titration method. The organic tissue dissolution by the solutions alone and in the presence of dentine powder was evaluated by weighing bovine tissue specimens before and after exposure to the solutions for 3 and 10 min. For the antimicrobial activity, biofilms of Enterococcus faecalis were exposed to the solutions for 3 min in the absence and presence of organic tissue and organic tissue + dentine debris. The biovolume and percentage of damaged membrane cells of the biofilm were measured by means of confocal microscopy and the live/dead technique. Nonparametric tests were used to determine statistical differences (P < 0.05). RESULTS: Both inhibitors consumed the free available chlorine of the solutions over time. The presence of dentine debris significantly reduced the tissue dissolution capacity of the NaOCl solutions (P < 0.05). The percentages of biovolume reduction were not affected by the presence of the inhibitors in the two NaOCl solutions, whereas the percentage of damaged membrane cells was significantly reduced (P < 0.001). Overall, a similar behaviour was observed in the NaOCl and NaOCl/HEDP groups. CONCLUSIONS: The presence of organic tissue and organic tissue + dentine debris favoured rapid consumption of the free chlorine of NaOCl and NaOCl/HEDP. This resulted in a decreased ability to dissolve organic tissue without affecting the short-term antimicrobial activity.

Etidronate-zinc Complex Ameliorated Cognitive and Synaptic Plasticity Impairments in 2-Vessel Occlusion Model Rats by Reducing Neuroinflammation.

As one of the bisphosphonate derivatives, etidronate has proved to be beneficial to spatial learning and memory deficits caused by two-vessel occlusion (2-VO). In this study, the novel drug etidronate-zinc complex (Eti-Zn) was used to detect its role in synaptic plasticity and learning and memory functions in a rat model of 2-VO. Chronic cerebral hypoperfusion was induced by permanent occlusion of the common carotid artery bilaterally in adult Sprague-Dawley rats. Eti-Zn (20 mg/kg/day, tail vein injection) was administered for 7 days after a two-week operation. After treatment, a series of tests were carried out. Here, we found that Eti-Zn could reduce spatial learning and memory impairments in 2-VO model rats via the Morris water maze test. We also found that animals treated with Eti-Zn showed preference for the new-object in the novel object recognition test. In addition, the long-term potentiation and depotentiation from the Schaffer collaterals to the CA1 region in the hippocampus were enhanced by Eti-Zn treatment in 2-VO model rats. Furthermore, Eti-Zn significantly up-regulated NMDA receptor (NR) 2A, NR2B, postsynaptic density protein 95 and synaptophysin levels and prevented the destruction of dendritic spines. Moreover, Eti-Zn treatment reduced both the over-activation of microglia and the expressions of neuroinflammatory cytokines (TNF-α, IL-1ß and IL-6) in the hippocampus. The increased NF-κB signaling pathway in the hippocampus of 2-VO rats was reversed after Eti-Zn treatment. In summary, these findings suggest that Eti-Zn could ameliorate the synaptic plasticity and cognitive impairments by reducing neuroinflammation in 2-VO model rats.

Etidronate prevents dystrophic cardiac calcification by inhibiting macrophage aggregation.

Cardiovascular calcification is associated with high risk of vascular disease. This involves macrophage infiltration of injured vascular tissue and osteoclast-related processes. Splenic monocytes from mice, that are predisposed (C3H) or resistant (B6) to calcification, were isolated and differentiated in vitro with M-CSF to generate macrophages, which aggregate to form multinucleated (MN) cells in the presence of RANKL. MN cell formation was significantly decreased in monocytes from resistant compared with calcifying mice. Conditioned media from C3H macrophages strongly induced calcification in vitro. However, medium from B6 macrophages inhibited calcification. An increase in ICAM-1 was detected in conditioned media from C3H macrophages compared with B6, suggesting a key role for this molecule in calcification processes. Due to natural genetic loss of Abcc6, the causal gene for cardiac calcification, C3H mice have reduced plasma levels of inorganic pyrophosphate (PPi), a potential calcification inhibitor. Supplementation of C3H mice with PPi or Etidronate prevented but did not completely reverse cardiac calcification. Our data provide strong evidence of the pathogenesis of macrophages and MNs during tissue calcification and suggest PPi or its analogue Etidronate as a potential inhibitor of MN formation and calcification. Furthermore, the adhesion molecule ICAM-1 was shown to play a key role in calcification.

Etidronate for Prevention of Ectopic Mineralization in Patients With Pseudoxanthoma Elasticum.

BACKGROUND: In pseudoxanthoma elasticum (PXE), low pyrophosphate levels may cause ectopic mineralization, leading to skin changes, visual impairment, and peripheral arterial disease. OBJECTIVES: The authors hypothesized that etidronate, a pyrophosphate analog, might reduce ectopic mineralization in PXE. METHODS: In the Treatment of Ectopic Mineralization in Pseudoxanthoma Elasticum trial, adults with PXE and leg arterial calcifications (n = 74) were randomly assigned to etidronate or placebo (cyclical 20 mg/kg for 2 weeks every 12 weeks). The primary outcome was ectopic mineralization, quantified with 18fluoride positron emission tomography scans as femoral arterial wall target-to-background ratios (TBRfemoral). Secondary outcomes were computed tomography arterial calcification and ophthalmological changes. Safety outcomes were bone density, serum calcium, and phosphate. RESULTS: During 12 months of follow-up, the TBRfemoral increased 6% (interquartile range [IQR]: -12% to 25%) in the etidronate group and 7% (IQR: -9% to 32%) in the placebo group (p = 0.465). Arterial calcification decreased 4% (IQR: -11% to 7%) in the etidronate group and increased 8% (IQR: -1% to 20%) in the placebo group (p = 0.001). Etidronate treatment was associated with significantly fewer subretinal neovascularization events (1 vs. 9, p = 0.007). Bone density decreased 4% ± 12% in the etidronate group and 6% ± 9% in the placebo group (p = 0.374). Hypocalcemia (<2.20 mmol/l) occurred in 3 versus 1 patient (8.1% vs. 2.7%, p = 0.304). Eighteen patients (48.6%) treated with etidronate, compared with 0 patients treated with placebo (p < 0.001), experienced hyperphosphatemia (>1.5 mmol/l) and recovered spontaneously. CONCLUSIONS: In patients with PXE, etidronate reduced arterial calcification and subretinal neovascularization events but did not lower femoral 18fluoride sodium positron emission tomography activity compared with placebo, without important safety issues. (Treatment of Ectopic Mineralization in Pseudoxanthoma elasticum; NTR5180).

Phase I/II trials of 186Re-HEDP in metastatic castration-resistant prostate cancer: post-hoc analysis of the impact of administered activity and dosimetry on survival.

PURPOSE: To investigate the role of patient-specific dosimetry as a predictive marker of survival and as a potential tool for individualised molecular radiotherapy treatment planning of bone metastases from castration-resistant prostate cancer, and to assess whether higher administered levels of activity are associated with a survival benefit. METHODS: Clinical data from 57 patients who received 2.5-5.1 GBq of 186Re-HEDP as part of NIH-funded phase I/II clinical trials were analysed. Whole-body and SPECT-based absorbed doses to the whole body and bone lesions were calculated for 22 patients receiving 5 GBq. The patient mean absorbed dose was defined as the mean of all bone lesion-absorbed doses in any given patient. Kaplan-Meier curves, log-rank tests, Cox's proportional hazards model and Pearson's correlation coefficients were used for overall survival (OS) and correlation analyses. RESULTS: A statistically significantly longer OS was associated with administered activities above 3.5 GBq in the 57 patients (20.1 vs 7.1 months, hazard ratio: 0.39, 95 % CI: 0.10-0.58, P = 0.002). A total of 379 bone lesions were identified in 22 patients. The mean of the patient mean absorbed dose was 19 (±6) Gy and the mean of the whole-body absorbed dose was 0.33 (±0.11) Gy for the 22 patients. The patient mean absorbed dose (r = 0.65, P = 0.001) and the whole-body absorbed dose (r = 0.63, P = 0.002) showed a positive correlation with disease volume. Significant differences in OS were observed for the univariate group analyses according to disease volume as measured from SPECT imaging of 186Re-HEDP (P = 0.03) and patient mean absorbed dose (P = 0.01), whilst only the disease volume remained significant in a multivariable analysis (P = 0.004). CONCLUSION: This study demonstrated that higher administered activities led to prolonged survival and that for a fixed administered activity, the whole-body and patient mean absorbed doses correlated with the extent of disease, which, in turn, correlated with survival. This study shows the importance of patient stratification to establish absorbed dose-response correlations and indicates the potential to individualise treatment of bone metastases with radiopharmaceuticals according to patient-specific imaging and dosimetry.

Histological evaluation of symptomatic ossification of the anterior longitudinal ligament treated with etidronate disodium: a case report.

BACKGROUND: Here we report the first autopsied case involving pathological examination after two resections of symptomatic ossification of the anterior longitudinal ligament with anterior osteophytes and etidronate treatment with more than 8 years of follow-up. CASE PRESENTATION: A 51-year-old Japanese man complained of severe dysphagia due to esophageal compression by ossification of his anterior longitudinal ligament with anterior cervical osteophytes. Although surgical removal of the anterior cervical osteophytes was performed following etidronate treatment (800 mg/day for 6 months), dysphagia occurred secondary to recurrent ossification of his anterior longitudinal ligament with anterior osteophytes 7 years after the initial resection. A second resection of the anterior cervical osteophytes was performed, and cyclic administration of etidronate disodium (1000 mg/day, 3-month administration and 3-month cessation) did not result in re-outgrowth of ossification of his anterior longitudinal ligament with anterior osteophytes. At 1 year and 6 months after the second surgery, he suddenly died. The pathological findings associated with the ossification of his anterior longitudinal ligament during etidronate therapy showed no recurrence of ossification of the anterior longitudinal ligament with anterior osteophytes. CONCLUSION: A recurrence of ossification of the anterior longitudinal ligament with anterior osteophytes formation, which caused dysphagia, was not observed with the cyclic administration of etidronate disodium at a dose of 1000 mg/day every 3 months for a period of 1 year and 5 months in the present case.

Effects of Dentin Debris on the Antimicrobial Properties of Sodium Hypochlorite and Etidronic Acid.

INTRODUCTION: The purpose of this study was to determine the influence of dentin powder on the concentration, pH, and antimicrobial activity of sodium hypochlorite (NaOCl) alone and combined with etidronic acid (HEBP). METHODS: Biofilms of Enterococcus faecalis were grown on the surface of dentin blocks for 5 days and then exposed to 1% and 2.5% NaOCl alone or combined with 9% HEBP for 3 minutes in the absence and presence of dentin powder. The biovolumes of the biofilm were measured using confocal microscopy and the live/dead technique. The available chlorine and pH of the solutions were also measured. Nonparametric tests were used to determine statistical differences (P < .05). RESULTS: The presence of dentin powder resulted in a reduction of the free available chlorine and pH in all the irrigating solutions; 1% NaOCl lost its antimicrobial activity completely in the presence of dentin powder. The antimicrobial activity was significantly reduced in the 2.5% NaOCl and 1% NaOCl/HEBP groups, and it was not affected in the 2.5% NaOCl/HEBP group. CONCLUSIONS: The presence of dentin powder significantly decreased the available chlorine and antimicrobial activity of 1% NaOCl, 2.5% NaOCl, and 1% NaOCl/HEBP irrigating solutions. The antimicrobial activity of 2.5% NaOCl/HEBP was not affected by the dentin powder after a 3-minute contact time against E. faecalis biofilms.

Fabrication of pluronic and methylcellulose for etidronate delivery and their application for osteogenesis.

Novel hydrogels were prepared by blending 4% (w/w) methylcellulose (MC) with various concentrations of 12, 14, 16, 18 and 20% (w/w) pluronic F127 (PF) to form injectable implant drug delivery systems. The blends formed gels using lower concentrations of PF compared to when using PF alone. Etidronate sodium (EDS) at a concentration of 4×10(-3)M was loaded into these blends for producing an osteogenesis effect. The pure gels or EDS loaded gels exhibited cytocompatibility to both the osteoblast (MC3T3-E1) and myoblast (C2C12) cell lines whereas the gels of 16PF, 18PF and 20PF were very cytotoxic to the cells. The EDS loaded gels demonstrated significantly greater alkaline phosphatase (ALP) activities compared to the pure gels. The longer exposure time periods of the samples to the cells, the greater was the ALP activity. These EDS loaded gels significantly increased proliferation of both cell lines thus indicating a bone regeneration effect. The PF/MC blends prolonged the in vitro release of EDS for more than 28 days. Based on the in vitro degradation test, the MC extensively improved the gel strength of the PF and delayed the degradation of the gels thus making them more functional for a sustained drug delivery for osteogenesis.

Epidemiología, farmacología y caracterización clínica de la osteonecrosis de los maxilares. Un estudio retrospectivo de 70 casos / Epidemiology, pharmacology and clinical characterization of bisphosphonate-related osteonecrosis of the jaw. A retrospective study of 70 cases

Introducción y objetivos: Los bisfosfonatos son fármacos con un amplio espectro de indicaciones cuya principal capacidad es la inhibición de la función osteoclástica. En el año 2003 se ha descrito una complicación asociada a su empleo, la osteonecrosis de los maxilares por bisfosfonatos (ONMB). Los objetivos del presente estudio son identificar los casos recogidos de ONMB en un hospital de tercer nivel durante 8 años, evaluando las principales variables en relación con la enfermedad, el bisfosfonato empleado y los factores de riesgo locales o generales que pudieran actuar como desencadenante en la patogénesis de la ONMB. Material y método: Se procedió a la selección los pacientes diagnosticados de ONMB en un centro de referencia para una población de 1.100.000 habitantes. Las variables analizadas se dividieron en 3 grupos: pacientes, fármaco (incluyendo el análisis de la dosis aplicada y la ponderación dosis/potencia) y osteonecrosis. Resultados: Se recogieron 70 casos (44 mujeres y 26 varones), con una media de 66,8 años. Dieciocho pacientes habían recibido un aminobisfosfonato oral y 52 por vía intravenosa. El tiempo medio de administración fue de 26,53 meses. En el 67,1% de los pacientes se pudo identificar un factor local desencadenante, siendo el más frecuente la exodoncia (48,6%). Aunque la exposición ósea estaba presente en el 75,7% de los casos, 8 enfermos padecieron una osteonecrosis sin exposición, manifestando la presencia de dolor y/o fístula crónica. El 58,6% experimentaron una resolución completa con un tiempo medio de control de 16,28 meses. Conclusiones: El 25% de las ONMB en nuestra serie se relacionaron con la administración de un bisfosfonato oral, especialmente el alendronato. El ácido zoledrónico es el agente que menos miligramos precisa para desarrollar la enfermedad. La exposición ósea solitaria fue el dato clínico más habitual, afectando especialmente a sectores posteriores mandibulares en pacientes con enfermedad metastásica (AU)

Background and objectives: Bisphosphonates are widely prescribed drugs whose principal capacity is inhibiting the osteoclast function. In 2003 a complication related to their administration, bisphosphonate-related osteonecrosis of the jaw (BRONJ), was described. The objectives of this study were to identify diagnosed cases of BRONJ in a third-level hospital over 8 years, evaluating the main features in relation to the disease, the bisphosphonate and the presence of local or general risk factors that could trigger the BRONJ. Material and method: Patients diagnosed with BRONJ in a centre of reference for a population of 1,100,000 inhabitants were selected. Variables analysed were classified into 3 groups: patients, bisphosphonate (focusing on dose and weighting dose/potency) and osteonecrosis. Results: Seventy cases were studied —44 women and 26 men—, with a mean age of 66.8 years. Eighteen patients received bisphosphonates orally and 52, intravenously. The mean time of administration was 26.53 months. In 67.1% of the patients it was possible to identify a local trigger, with the most common being tooth extraction (48.6%). Bone exposure was present in 89.2% of the cases, while 12 patients developed BRONJ without exposed bone, with only pain and/or chronic sinus tracts. Complete resolution was achieved in 58.6% of the patients, with a mean time of control of 16.28 months. Conclusions: 25% of the BRONJ cases were related to the administration of oral bisphosphonates, especially alendronate. Zoledronic acid was the bisphosphonate that required the fewest milligrams to induce osteonecrosis. Single bone exposure was the most common clinical finding, especially in the molar mandibular region in patients with metastatic disease (AU)

Risedronate as an intra-abdominal sepsis mimic: a case report.

UNLABELLED: This case report highlights the potential severity of bisphosphonate-associated reactions. CASE REPORT: A 76-year-old lady underwent several hospital admissions for investigation of fever associated with rigors, abdominal pain, and vomiting. DISCUSSION: Despite multiple investigations, no cause was found, but the timing of the symptoms coincided with monthly risedronate administration.

Compliance, persistence, and preference outcomes of postmenopausal osteoporotic women receiving a flexible or fixed regimen of daily risedronate: A multicenter, prospective, parallel group study.

OBJECTIVE: The aim of this study was to examine the level of compliance and persistence in patients with postmenopausal osteoporosis (OP) receiving daily risedronate (5 mg) with either fixed dosing of three different timing regimens (A: before breakfast; B: in-between meals; C: before bedtime) or with flexible dosing and the effect on urinary N-terminal telopeptide of Type 1 collagen (NTX-1). METHODS: The study included 448 patients with postmenopausal OP. Patients were randomly assigned into six treatment groups each with a permutation of the treatment sequence (ABC, BCA, etc.) in the crossover phase (3 x 1 week) and randomized to 23 weeks of either the daily flexible (either regimen A, B or C) or fixed timing (only regimen A, B, or C) in the patient's preference phase. Urinary NTX-1 was tested. RESULTS: A total of 433 patients participated in the patient's preference phase (49.7% preferred flexible and 50.3% fixed timing). There was no significant difference between the proportion of responders who were both compliant and persistent in the flexible (54.4%) and fixed regimens (53.7%) (p=0.8803). A significant difference between the flexible and fixed regimens was seen in persistence in favor of the flexible regimen (p=0.0306). There was no significant difference between the flexible and fixed regimens in terms of compliance (p=0.4611). Change in urinary NTX-1 did not show any difference between the two regimens. At the final visit, 51% of patients in the flexible and 55% in the fixed regimen group considered the used risedronate regimen as excellent or very good (p=0.1440). CONCLUSION: A flexible dosing with daily risedronate appears be a valuable option in terms of compliance and persistence for patients with postmenopausal OP.

Cranial base pathology in pediatric osteogenesis imperfecta patients treated with bisphosphonates.

OBJECT: Cranial base pathology is a serious complication of osteogenesis imperfecta (OI). Our aim was to analyze whether bisphosphonate treatment, used to improve bone strength, could also prevent the development of craniocervical junction pathology (basilar impression, basilar invagination, or platybasia) in children with OI. METHODS: In this single-center retrospective study the authors analyzed the skull base morphology from lateral skull radiographs and midsagittal MR images (total of 94 images), obtained between the ages of 0 and 25 years in 39 bisphosphonate-treated OI patients. The results were compared with age-matched normative values and with findings in 70 OI patients who were not treated with bisphosphonates. In addition to cross-sectional data, longitudinal data were available from 22 patients with an average follow-up period of 7.6 years. The patients, who had OI types I, III, IV, VI, and VII, had been treated with zoledronic acid, pamidronate, or risedronate for 3.2 years on average. RESULTS: Altogether 33% of the 39 bisphosphonate-treated patients had at least 1 cranial base anomaly, platybasia being the most prevalent diagnosis (28%). Logistic regression analysis suggested a higher risk of basilar impression or invagination in patients with severe OI (OR 22.04) and/or older age at initiation of bisphosphonate treatment (OR 1.45), whereas a decreased risk was associated with longer duration of treatment (OR 0.28). No significant associations between age, height, or cumulative bisphosphonate dose and the risk for cranial base anomaly were detected. In longitudinal evaluation, Kaplan-Meier curves suggested delayed development of cranial base pathology in patients treated with bisphosphonates but the differences from the untreated group were not statistically significant. CONCLUSIONS: These findings indicate that cranial base pathology may develop despite bisphosphonate treatment. Early initiation of bisphosphonate treatment may delay development of craniocervical junction pathology. Careful followup of cranial base morphology is warranted, particularly in patients with severe OI.

Timing of the initiation of bisphosphonates after surgery for fracture healing: a systematic review and meta-analysis of randomized controlled trials.

SUMMARY: We performed a systematic review and meta-analysis of randomized clinical trials. Early administration of bisphosphonates (BPs) after surgery did not appear to delay fracture healing time either radiologically or clinically. Furthermore, the anti-resorptive efficacy of BPs given immediately after surgical repair should positively affect the rate of subsequent fractures. INTRODUCTION: Bisphosphonates (BPs) are widely used in the prophylaxis and treatment of osteoporosis. However, early administration of BPs after surgical repair of a fracture may limit the reserve capacity of bone to heal. The aim of this review and meta-analysis was to analyze the benefits and adverse effects of early administration of BPs and give recommendations regarding when BPs should be utilized. METHODS: We identified randomized controlled trials comparing the early administration of BPs to placebo, delayed BP treatment, or no therapy in adult patients after surgery. The search was performed in PubMed, the Cochrane Library, and Embase. RESULTS: Ten studies with 2888 patients were included. Four trials used alendronate, three trials used zoledronic, two trials used risedronate, and one trial used etidronate. Early administration of BPs was considered less than 3 months after surgery. Patients treated with BP therapy had no significant differences in radiological fracture healing times compared with patients in the control group (mean difference [MD] 0.47, 95% confidence interval [CI] -2.75 to 3.69). There were also no significant differences in the rate of delay or nonunion of fracture healing (odds ratio [OR] 0.98, 95% CI 0.64 to 1.50). However, the bone mineral density (BMD) of total hips did significantly improve after 12 months of treatment with BPs. And most bone turnover markers of patients in the study group were significantly decreased. CONCLUSIONS: Early administration of BPs after surgery did not appear to delay fracture healing time either radiologically or clinically. Furthermore, according to the changes in BMD and bone turnover markers, the anti-resorptive efficacy of BPs given immediately after surgical repair should positively affect the rate of subsequent fractures.

Epidemiology, pharmacology and clinical characterization of bisphosphonate-related osteonecrosis of the jaw. A retrospective study of 70 cases.

BACKGROUND AND OBJECTIVES: Bisphosphonates are widely prescribed drugs whose principal capacity is inhibiting the osteoclast function. In 2003 a complication related to their administration, bisphosphonate-related osteonecrosis of the jaw (BRONJ), was described. The objectives of this study were to identify diagnosed cases of BRONJ in a third-level hospital over 8 years, evaluating the main features in relation to the disease, the bisphosphonate and the presence of local or general risk factors that could trigger the BRONJ. METHODS: Patients diagnosed with BRONJ in a centre of reference for a population of 1,100,000 inhabitants were selected. Variables analysed were classified into 3 groups: patients, bisphosphonate (focusing on dose and weighting dose/potency) and osteonecrosis. RESULTS: Seventy cases were studied -44 women and 26 men-, with a mean age of 66.8 years. Eighteen patients received bisphosphonates orally and 52, intravenously. The mean time of administration was 26.53 months. In 67.1% of the patients it was possible to identify a local trigger, with the most common being tooth extraction (48.6%). Bone exposure was present in 89.2% of the cases, while 12 patients developed BRONJ without exposed bone, with only pain and/or chronic sinus tracts. Complete resolution was achieved in 58.6% of the patients, with a mean time of control of 16.28 months. CONCLUSIONS: 25% of the BRONJ cases were related to the administration of oral bisphosphonates, especially alendronate. Zoledronic acid was the bisphosphonate that required the fewest milligrams to induce osteonecrosis. Single bone exposure was the most common clinical finding, especially in the molar mandibular region in patients with metastatic disease.

Bone safety with risedronate: histomorphometric studies at different dose levels and exposure.

UNLABELLED: This report describes bone safety and histomorphometric data across different dose levels and dosing frequencies of risedronate. Normal bone structure and histomorphometric data were observed, with ongoing bone remodeling and mineralization regardless of dose. These data are reassuring and do not suggest compromised bone remodeling during treatment with established risedronate regimens. INTRODUCTION: The efficacy and bone safety of risedronate 5 mg daily were established in pivotal phase III randomized, placebo-controlled clinical studies. Histomorphometric analysis of paired biopsies demonstrated bone safety as reflected by presence of fluorescent tetracycline double-labels in all evaluable biopsies. This report describes bone safety and histomorphometric data across studies of various dose regimens of risedronate. METHODS: Bridging studies, with bone mineral density as the primary endpoint, demonstrated non-inferiority of risedronate 35 mg and 50 mg once a week, risedronate 150 mg once a month, and a risedronate 75-mg dose on two consecutive days a month versus risedronate 5 mg daily. The low oral bioavailability and known dosing limitations due to food interactions of bisphosphonates have led to development of an oral delayed-release dose form of risedronate 35 mg to be taken weekly, before or after breakfast. Bone biopsies were collected at 24 months in studies involving these risedronate dosing regimens; bone safety and histomorphometric data were evaluated. RESULTS: Qualitative bone histology showed normal mineralization of newly formed bone without evidence of pathological findings, such as osteomalacia, bone marrow dyscrasia, or bone marrow fibrosis. Importantly, ongoing bone remodeling, based on fluorochrome labeling, was observed in all patients regardless of dose and exposure. Key histomorphometric variables were comparable to those observed with the risedronate 5 mg daily dose and were within the range seen in healthy pre- and post-menopausal women. CONCLUSIONS: Overall, the results are reassuring with respect to bone safety and histomorphometric data, and do not suggest oversuppression of bone remodeling during treatment with these established risedronate regimens.

Residual effect after oral bisphosphonate treatment and healthy adherer effects--the Swedish Adherence Register Analysis (SARA).

UNLABELLED: Little is known of the effect of alendronate and risedronate on osteoporotic fractures after discontinuation of therapy. We found that time on treatment was significantly inversely associated with the incidence of hospitalized fractures during posttreatment follow-up. Our results will inform health economic analysis of osteoporosis interventions. INTRODUCTION: Real-world persistence to treatment of osteoporosis is well-understood, but little is known of the posttreatment residual effect on fractures. The objective of this study was to investigate the residual effect of alendronate and risedronate on fractures and assess whether a healthy adherer effect confounds the association between persistence and residual anti-fracture effect. METHODS: A treatment-naïve cohort from the Swedish Prescribed Drug Register was identified through prescriptions for alendronate or risedronate between 2005 and 2009. Persistence was estimated, and patients were stratified by time on treatment (<1 month, 1-6 months, 7-12 months, and >12 months). Survival analysis was used to study hospitalized fractures and mortality up to 18 months after treatment discontinuation. RESULTS: The crude incidence proportion of fractures the first 6 months after treatment discontinuation ranged from 2.26% (<1 month of treatment) to 1.16% (>12 months). The corresponding estimates for month 7 to 12 after discontinuation was 3.18 to 1.96%, and for month 13 to 18 after discontinuation 2.69 to 1.95%. Adjusted regression results showed that patients persisting with therapy for >12 months had 60% lower fracture risk the first six months after treatment discontinuation (RR 0.40, p = 0.001). Patient characteristics, including prevalent fractures and co-morbidities, and posttreatment mortality were comparable across persistence durations, and we found no evidence of a healthy adherer effect. CONCLUSIONS: Time on bisphosphonate treatment was significantly inversely associated with the incidence of hospitalized fractures during posttreatment follow-up. We found no evidence of a healthy adherer effect confounding the relationship between treatment persistence and fracture risk.