87 resultados para bisphosphonate
Resumo:
Abstract: Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is characterized as exposed bone in the jaws for more than 8 weeks in patients with current or previous history of therapy with bisphosphonates (BPs) and no history of radiotherapy in the head and neck. We report a case series of 7 patients with BRONJ and analyze the variations of clinical and imaging signs, correlating them with the presence or absence of bone exposure. Among the patients, 6 were women and 1 was a man, aged 42–79 years. Five of the patients were using zoledronic acid and the other 2 alendronate. The use of BPs varied from 3 to 13 years. In 5 patients, tooth extraction was the triggering event of injuries. Panoramic radiographs and computed tomography (CT) were evaluated by a radiologist blinded to the cases. There were persistent unremodeled extraction socket even several months after tooth extraction in 3 of the cases that were consistent wit CT findings that also showed areas of osteosclerosis and osteolysis. Patients were treated according to the recommendations of the AAOMS, with surgical debridement and antibiotic coverage with amoxicillin in the symptomatic patients. The follow-up of these patients ranged from 8 to 34 months, with a good response to treatment. The image findings in this case series were not specific and showed no difference between each stages of BRONJ (AAOMS, 2009). The image features were similar in presence or absence of exposed bone.
Resumo:
A case is presented of extensive alveolar bone grafting in a patient with bilateral cleft lip and palate and polyostotic fibrous dysplasia. The patient previously underwent bisphosphonate therapy. Because of an abnormal and often decreased bone turnover caused by the fibrous dysplasia and the bisphosphonate therapy, bone grafting in such a patient poses several potential difficulties. In addition, the histomorphometric analysis of the bone grafts showed markedly decreased bone turnover. However, alveolar bone grafting using the iliac crest was performed successfully. Sufficient occlusion was achieved by postoperative low-loading orthodontic treatment.
Resumo:
A new technique was evaluated to identify changes in bone metabolism directly at high sensitivity through isotopic labeling of bone Ca. Six women with low BMD were labeled with 41Ca up to 700 days and treated for 6 mo with risedronate. Effect of treatment on bone could be identified using 41Ca after 4-8 wk in each individual. INTRODUCTION: Isotopic labeling of bone using 41Ca, a long-living radiotracer, has been proposed as an alternative approach for measuring changes in bone metabolism to overcome current limitations of available techniques. After isotopic labeling of bone, changes in urinary 41Ca excretion reflect changes in bone Ca balance. The aim of this study was to validate this new technique against established measures. Changes in bone Ca balance were induced by giving a bisphosphonate. MATERIALS AND METHODS: Six postmenopausal women with diagnosed osteopenia/osteoporosis received a single oral dose of 100 nCi 41Ca for skeleton labeling. Urinary 41Ca/40Ca isotope ratios were monitored by accelerator mass spectrometry up to 700 days after the labeling process. Subjects received 35 mg risedronate per week for 6 mo. Effect of treatment was monitored using the 41Ca signal in urine and parallel measurements of BMD by DXA and biochemical markers of bone metabolism in urine and blood. RESULTS: Positive response to treatment was confirmed by BMD measurements, which increased for spine by +3.0% (p = 0.01) but not for hip. Bone formation markers decreased by -36% for bone alkaline phosphatase (BALP; p = 0.002) and -59% for procollagen type I propeptides (PINP; p = 0.001). Urinary deoxypyridinoline (DPD) and pyridinoline (PYD) were reduced by -21% (p = 0.019) and -23% (p = 0.009), respectively, whereas serum and urinary carboxy-terminal teleopeptides (CTXs) were reduced by -60% (p = 0.001) and -57.0% (p = 0.001), respectively. Changes in urinary 41Ca excretion paralleled findings for conventional techniques. The urinary 41Ca/40Ca isotope ratio was shifted by -47 +/- 10% by the intervention. Population pharmacokinetic analysis (NONMEM) of the 41Ca data using a linear three-compartment model showed that bisphosphonate treatment reduced Ca transfer rates between the slowly exchanging compartment (bone) and the intermediate fast exchanging compartment by 56% (95% CI: 45-58%). CONCLUSIONS: Isotopic labeling of bone using 41Ca can facilitate human trials in bone research by shortening of intervention periods, lowering subject numbers, and having easier conduct of cross-over studies compared with conventional techniques.
Resumo:
Bone mass, bone geometry and its changes are based on trabecular and cortical bone remodeling. Whereas the effects of estrogen loss, rheumatoid arthritis (RA), glucocorticoid (GC) and bisphosphonate (BP) on trabecular bone remodeling have been well described, the effects of these conditions on the cortical bone geometry are less known. The present review will report current knowledge on the effects of RA, GC and BP on cortical bone geometry and its clinical relevance. Estrogen deficiency, RA and systemic GC lead to enhanced endosteal bone resorption. While in estrogen deficiency and under GC therapy endosteal resorption is insufficiently compensated by periosteal apposition, RA is associated with some periosteal bone apposition resulting in a maintained load-bearing capacity and stiffness. In contrast, BP treatment leads to filling of endosteal bone cavities at the epiphysis; however, periosteal apposition at the bone shaft seems to be suppressed. In summary, estrogen loss, RA and GC show similar effects on endosteal bone remodeling with an increase in bone resorption, whereas their effect on periosteal bone remodeling may differ. Despite over 50 years of GC therapy and over 25 years of PB therapy, there is still need for better understanding of the skeletal effects of these drugs as well as of inflammatory disease such as RA on cortical bone remodeling.
Resumo:
Bisphosphonates represent a unique class of drugs that effectively treat and prevent a variety of bone-related disorders including metastatic bone disease and osteoporosis. High tolerance and high efficacy rates quickly ranked bisphosphonates as the standard of care for bone-related diseases. However, in the early 2000s, case reports began to surface that linked bisphosphonates with osteonecrosis of the jaw (ONJ). Since that time, studies conducted have corroborated the linkage. However, as with most disease states, many factors can contribute to the onset of disease. The aim of this study was to determine which comorbid factors presented an increased risk for developing ONJ in cancer patients.^ Using a case-control study design, investigators used a combination of ICD-9 codes and chart review to identify confirmed cases of ONJ at The University of Texas M. D. Anderson Cancer Center (MDACC). Each case was then matched to five controls based on age, gender, race/ethnicity, and primary cancer diagnosis. Data querying and chart review provided information on variables of interest. These variables included bisphosphonate exposure, glucocorticoids exposure, smoking history, obesity, and diabetes. Statistical analysis was conducted using PASW (Predictive Analytics Software) Statistics, Version 18 (SPSS Inc., Chicago, Illinois).^ One hundred twelve (112) cases were identified as confirmed cases of ONJ. Variables were run using univariate logistic regression to determine significance (p < .05); significant variables were included in the final conditional logistic regression model. Concurrent use of bisphosphonates and glucocorticoids (OR, 18.60; CI, 8.85 to 39.12; p < .001), current smokers (OR, 2.52; CI, 1.21 to 5.25; p = .014), and presence of diabetes (OR, 1.84; CI, 1.06 to 3.20; p = .030) were found to increase the risk for developing ONJ. Obesity was not associated significantly with ONJ development.^ In this study, cancer patients that received bisphosphonates as part of their therapeutic regimen were found to have an 18-fold increase in their risk of developing ONJ. Other factors included smoking and diabetes. More studies examining the concurrent use of glucocorticoids and bisphosphonates may be able to strengthen any correlations.^
Resumo:
This paper reports the use of X-ray photoelectron spectroscopy (XPS) to investigate bisphosphonate (BP) adsorption onto plasma sprayed hydroxyapatite (HA) coatings commonly used for orthopaedic implants. BPs exhibit high binding affinity for the calcium present in HA and hence can be adsorbed onto HA-coated implants to exploit their beneficial properties for improved bone growth at the implant interface. A rigorous XPS analysis of pamidronate, a commonly used nitrogenous BP, adsorbed onto plasma sprayed HA-coated cobalt-chromium substrates has been carried out, aimed at: (a) confirming the adsorption of this BP onto HA; (b) studying the BP diffusion profile in the HA coating by employing the technique of XPS depth profiling; (c) confirming the bioactivity of the adsorbed BR XPS spectra of plasma sprayed HA-coated discs exposed to a 10 mM aqueous BP solution (pamidronate) for periods of 1, 2 and 24 h showed nitrogen and phosphorous photoelectron signals corresponding to the BP confirming its adsorption onto the HA substrate. XPS depth profiling of the 2 h BP-exposed HA discs showed penetration of the BP into the HA matrix to depths of at least 260 nm. The bioactivity of the adsorbed BP was confirmed by the observed inhibition of osteoclast (bone resorbing) cell activity. In comparison to the HA sample, the HA sample with adsorbed BP exhibited a 25-fold decrease in primary osteoclast cells. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
International audience
Resumo:
Os bisfosfonatos são um grupo de medicamentos utilizados no tratamento de doenças malignas metastáticas e em outras doenças ósseas como osteoporose e doença de Paget. A despeito dos seus benefícios, uma importante complicação denominada de osteonecrose dos maxilares vem sendo observada nos pacientes usuários crônicos dos bisfosfonatos que se caracteriza clinicamente por exposições ósseas na região maxilofacial persistente, acompanhadas de osteomielite, geralmente sintomáticas e cujo tratamento é complexo. Este estudo tem por objetivo revisar a literatura sobre a osteonecrose associada ao uso dos bisfosfonatos, em especial, em oncologia, no período de 2003 a 2008. Serão apresentados e discutidos os fatores de risco, aspectos etiopatogênicos, clínicos, imagenológicos, terapêuticos e preventivos desta doença. Devido à dificuldade de tratamento da osteonecrose associada aos bisfosfonatos, o foco deve ser a prevenção, sendo o ideal a eliminação de quadros infecciosos orais antes da terapia com os bisfosfonatos ter sido iniciada e minimizar traumas em boca após o uso destes medicamentos.
Resumo:
Objectives This study evaluated the influence of oestrogen deficiency and its therapies on bone tissue around osseointegrated implants. Methods Implants were placed in 66 female rats tibiae. The animals were assigned into five groups: control (CTL), sham, ovariectomy (OVX), oestrogen (EST), and alendronate (ALE). While CTL was sacrificed 60 days after implant placement, other groups were subjected to ovariectomy or sham surgery according to group and euthanized after 90 days. Blood and urine samples were collected at sacrifice day for osteocalcin (OCN) and deoxypyridinoline (DPD) quantification. Densitometry of femur and lumbar vertebrae was performed in order to evaluate rats` skeletal impairment. Non-decalcified sections were referred to fluorescent and light microscopy for analyses of mineral apposition rate (MAR), eroded and osteoclastic surfaces, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO). Results Results from the OVX group showed significantly lower bone mineral density (BMD), BIC, BAFO, and MAR, while OCN, deoxipiridinoline, eroded surface and ostecoclastic surface were increased compared with the other groups of the study. ALE reduced OCN and DPD concentrations, MAR, osteoclastic and eroded surfaces, and no difference was in BIC and BAFO relative to SHAM. EST and CTL showed similar results to SHAM for measurements. Conclusions Oestrogen deficiency exerted a negative influence on bone tissue around implants, while oestrogen replacement therapy and alendronate were effective against its effects. Although alendronate therapy maintained the quantity of bone around implants, studies evaluating bone turnover kinetics are warranted. To cite this article:Giro G, Coelho PG, Pereira RMR, Jorgetti V, Marcantonio E Jr, Orrico SRP. The effect of oestrogen and alendronate therapies on postmenopausal bone loss around osseointegrated titanium implants.Clin. Oral Impl. Res. 22, 2011; 259-264.doi: 10.1111/j.1600-0501.2010.01989.x.
Resumo:
Osteonecrosis of the jaw (ONJ), previously an entity associated with radiation therapy to the head and neck, has been observed in patients treated with bisphosphonates. Patients with metastatic breast cancer and myelomatous bone disease, commonly treated with high-potency nitrogen-containing bisphosphonates for a prolonged period of time, have the greatest risk of ONJ development. The reported frequency of ONJ ranges from 0.6% to 6.2% in breast cancer and from 1.7% to 15% in patients with multiple myeloma. Osteonecrosis of the jaw has also been observed in patients with other cancers such as prostate cancer and in benign bone disorders such as osteoporosis and Paget`s disease in which the incidence is low. Risk factors associated with the development of ONJ include dental extractions, length of bisphosphonate treatment, and the type of bisphosphonate used. In this review, we summarize the reported incidence and risk factors associated with ONJ.
Resumo:
We recently demonstrated that suppression of bone remodeling allows microdamage to accumulate, leading to reduced bone toughness in the rib cortex of dogs. This study evaluates the effects of reduced bone turnover produced by bisphosphonates on microdamage accumulation and biomechanical properties at clinically relevant skeletal sites in the same dogs. Thirty-six female beagles, 1-2 years old, were divided into three groups. The control group was treated daily for 12 months with saline vehicle (CNT), The remaining two groups were treated daily with risedronate at a dose of 0.5 mg/kg per day (RIS), or alendronate at 1.0 mg/kg per day (ALN) orally, The doses of these bisphosphonates were six times the clinical doses approved for treatment of osteoporosis in humans. After killing, the L-1 vertebra was scanned by dual-energy X-ray absorptiometry (DXA), and the L-2 vertebra and right ilium were assigned to histomorphometry, The L-3 vertebra, left ilium, Th-2 spinous process, and right femoral neck were used for microdamage analysis. The L-4 vertebra and Th-1 spinous process were mechanically tested to failure in compression and shear, respectively. One year treatment with risedronate or alendronate significantly suppressed trabecular remodeling in vertebrae (RIS 90%, ALN 95%) and ilium (RIS 76%, ALN 90%) without impairment of mineralization, and significantly increased microdamage accumulation in all skeletal sites measured. Trabecular bone volume and vertebral strength increased significantly following 12 month treatment. However, normalized toughness of the L-4 vertebra was reduced by 21% in both RIS (p = 0.06) and ALN (p = 0.05) groups. When the two bisphosphonate groups were pooled in a post hoc fashion for analysis, this reduction in toughness reached statistical significance (p = 0.02), This study demonstrates that suppression of trabecular bone turnover by high doses of bisphosphonates is associated with increased vertebral strength, even though there is significant microdamage accumulation and a reduction in the intrinsic energy absorption capacity of trabecular bone. (C) 2001 by Elsevier Science Inc. All rights reserved.