Bisphosphonate Exposure Research Articles

Osteonecrosis of the Jaw and Nonmalignant Disease: Is There an Association with Rheumatoid Arthritis?

To review cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) occurring in association with benign disease and to describe and compare the clinical course and outcome for patients with BRONJ and rheumatoid arthritis (RA) or osteoporosis. We retrospectively reviewed observations of all patients referred for treatment and followup for BRONJ from January 2007 to December 2011. Only patients with malignant disease were excluded. Demographic data, medical history, maxillofacial findings, BRONJ treatment, and followup were reviewed for each case. Over a 5-year period, we diagnosed 112 patients with BRONJ. Among these patients, 15 received bisphosphonate (BP) treatment for nonmalignant disease (mean age 65.7 ± 19.8 yrs, 80% women). Patients received BP for a variety of reasons: 8 (53%) to prevent osteoporosis in association with underlying RA; 6 (40%) to prevent idiopathic osteoporosis; and 1 (7%) to treat ankle algodystrophy. The mean oral BP exposure period was 48.4 months (median 36 mo). In 13 cases (86.6%), BRONJ was diagnosed following dental extraction. Of the 8 patients with RA, 5 (62.5%) were taking prednisone at the time of the discovery of BRONJ. Major surgery, sequestrectomy, or alveolectomy was performed in 9 patients (60%), all of whom healed within 3 to 36 months (mean 11.5 mo). Comparative analysis of all the variables showed no statistically significant differences between patients with RA and others. ONJ is a rare adverse effect of BP therapy, especially when administered orally. Within the limits of our study, we were unable to demonstrate a difference in BRONJ disease spectrum, clinical course, or outcome between patients with and those without RA.

Bisphosphonates and risk of subtrochanteric, femoral shaft, and atypical femur fracture: A systematic review and meta-analysis

Although there is strong evidence that bisphosphonates prevent certain types of osteoporotic fractures, there are concerns that these medications may be associated with rare atypical femoral fractures (AFF). Recent published studies examining this potential association are conflicting regarding the existence and strength of this association. We conducted a systematic review and meta-analysis of published studies examining the association of bisphosphonates with subtrochanteric, femoral shaft, and AFF. The random-effects model was used to calculate the pooled estimates of adjusted risk ratios (RR). Subgroup analysis was performed by study design, for studies that used validated outcome definitions for AFF, and for studies reporting on duration of bisphosphonate use. Eleven studies were included in the meta-analysis: five case-control and six cohort studies. Bisphosphonate exposure was associated with an increased risk of subtrochanteric, femoral shaft, and AFF, with adjusted RR of 1.70 (95% confidence interval [CI], 1.22-2.37). Subgroup analysis of studies using the American Society for Bone and Mineral Research criteria to define AFF suggests a higher risk of AFF, with bisphosphonate use with RR of 11.78 (95% CI, 0.39-359.69) as compared to studies using mainly diagnosis codes (RR, 1.62; 95% CI, 1.18-2.22), although there is a wide confidence interval and severe heterogeneity (I(2) = 96.15%) in this subgroup analysis. Subgroup analysis of studies examining at least 5 years of bisphosphonate use showed adjusted RR of 1.62 (95% CI, 1.29-2.04). This meta-analysis suggests there is an increased risk of subtrochanteric, femoral shaft, and AFF among bisphosphonate users. Further research examining the risk of AFF with long-term use of bisphosphonates is indicated as there was limited data in this subgroup. The public health implication of this observed increase in AFF risk is not clear.

The effect of bisphosphonate therapy on neutrophil function: a potential biomarker

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) occurs subsequent to intravenous and oral bisphosphonate exposure in a small subset of patients. The identification of the pathophysiologic mechanisms has not been fully elucidated. Evidence of concurrent bacterial colonization at sites of bone necrosis, previous reports of neutrophil-related complications in some patients taking some bisphosphonates, along with perturbed neutrophil function in bisphosphonate-treated mice, suggest an innate immune role in the development of BRONJ. This study investigated neutrophil function in BRONJ patients to determine if neutrophil functional defects may serve as a potential biomarker for BRONJ susceptibility. Two populations were studied: patients with BRONJ and those beginning intravenous pamidronate. Healthy control patients were used for comparison. Twenty-three patients with BRONJ and five patients who were beginning pamidronate therapy provided neutrophil samples from the mouth (oral rinses) and from blood. Neutrophils from the population of patients with BRONJ and from those post-pamidronate treatment showed lower reactive-oxygen species production and impaired chemotaxis relative to controls. These data suggest that a compromise in neutrophil function may be a potential biomarker for BRONJ susceptibility.

Bisphosphonates as a risk factor for adverse orthodontic outcomes: A retrospective cohort study

Bisphosphonates are a class of drugs commonly prescribed to treat osteoporosis. They act by decreasing the resorption of bone. Since tooth movement depends on bone remodeling, these drugs can impact orthodontic treatment. The purpose of this study was to evaluate the extent to which bisphosphonate therapy is a risk factor for poor orthodontic outcomes. Orthodontists were invited to participate in the study by performing case reviews of women over age 50 who were treated from 2002 through 2008. Women who used bisphosphonates were compared with women who did not have a history of bisphosphonate use. Outcomes assessed included treatment time, osteonecrosis of the jaws, incisor alignment, incomplete space closure, and root parallelism. The records for 20 subjects with bisphosphonate exposure were collected, as well as records for 93 subjects without bisphosphonate exposure. In patients undergoing extractions, treatment times were significantly longer if they had a history of bisphosphonate use. No occurrences of osteonecrosis of the jaws were reported, nor did patients end treatment with incisor alignment discrepancies greater than 1 mm, regardless of bisphosphonate exposure. Among patients with extractions or initial spacing, there were higher odds of incomplete space closure (odds ratio, 13) and poor root parallelism (odds ratio, 26) at the end of treatment for patients using bisphosphonates. Bisphosphonate use is associated with longer treatment times among extraction patients, increased odds of poor space closure, and increased odds of poor root parallelism.

Microindentation for in vivo measurement of bone tissue material properties in atypical femoral fracture patients and controls

Atypical femoral fractures (AFF) associated with long-term bisphosphonates (LTB) are a growing concern. Their etiology is unknown, but bone material properties might be deteriorated. In an AFF series, we analyzed the bone material properties by microindentation. Four groups of patients were included: 6 AFF, 38 typical osteoporotic fractures, 6 LTB, and 20 controls without fracture. Neither typical osteoporotic fractures nor controls have received any antiosteoporotic medication. A general laboratory workup, bone densitometry by dual-energy X-ray absorptiometry (DXA), and microindentation testing at the tibia were done in all patients. Total indentation distance (Total ID), indentation distance increase (IDI), and creep indentation distance (Creep ID) were measured (microns). Age-adjusted analysis of covariance (ANCOVA) was used for comparisons. Controls were significantly younger than fracture groups. Bisphosphonate exposure was on average 5.5 years (range 5 to 12 years) for the AFF and 5.4 years (range 5 to 8 years) for the LTB groups. Total ID (microns) showed better material properties (lower Total ID) for controls 36 (± 6; mean ± SD) than for AFF 46 (± 4) and for typical femoral fractures 47 (± 13), respectively. Patients on LTB showed values between controls and fractures, 38 (± 4), although not significantly different from any of the other three groups. IDI values showed a similar pattern 13 (± 2), 16 (± 6), 19 (± 3), and 18 (± 5). After adjusting by age, significant differences were seen between controls and typical (p < 0.001) and atypical fractures (p = 0.03) for Total ID and for IDI (p < 0.001 and p < 0.05, respectively). There were no differences in Creep ID between groups. Our data suggest that patients with AFF have a deep deterioration in bone material properties at a tissue level similar to that for the osteoporotic fracture group. The LTB group shows levels that are in between controls and both type of fractures, although not statistically different. These results suggest that bisphosphonate therapy probably does not put the majority of patients at risk for AFF.

Incidence of atypical nontraumatic diaphyseal fractures of the femur

Bisphosphonates reduce the rate of osteoporotic fractures in clinical trials and community practice. "Atypical" nontraumatic fractures of the diaphyseal (subtrochanteric or shaft) part of the femur have been observed in patients taking bisphosphonates. We calculated the incidence of these fractures within a defined population and examined the incidence rates according to duration of bisphosphonate use. We identified all femur fractures from January 1, 2007 until December 31, 2011 in 1,835,116 patients older than 45 years who were enrolled in the Healthy Bones Program at Kaiser Southern California, an integrated health care provider. Potential atypical fractures were identified by diagnostic or procedure codes and adjudicated by examination of radiographs. Bisphosphonate exposure was derived from internal pharmacy records. The results showed that 142 patients had atypical fractures; of these, 128 had bisphosphonate exposure. There was no significant correlation between duration of use (5.5 ± 3.4 years) and age (69.3 ± 8.6 years) or bone density (T-score -2.1 ± 1.0). There were 188,814 patients who had used bisphosphonates. The age-adjusted incidence rates for an atypical fracture were 1.78/100,000/year (95% confidence interval [CI], 1.5-2.0) with exposure from 0.1 to 1.9 years, and increased to 113.1/100,000/year (95% CI, 69.3-156.8) with exposure from 8 to 9.9 years. We conclude that the incidence of atypical fractures of the femur increases with longer duration of bisphosphonate use. The rate is much lower than the expected rate of devastating hip fractures in elderly osteoporotic patients. Patients at risk for osteoporotic fractures should not be discouraged from initiating bisphosphonates, because clinical trials have documented that these medicines can substantially reduce the incidence of typical hip fractures. The increased risk of atypical fractures should be taken into consideration when continuing bisphosphonates beyond 5 years.

Incidence of osteonecrosis of the jaw among users of bisphosphonates with selected cancers or osteoporosis

To quantify the incidence of osteonecrosis of the jaw (ONJ) by bisphosphonate exposure among two cohorts of patients. In a retrospective cohort study, we identified cohort members via health insurance claim diagnosis codes and identified potential cases of ONJ that were confirmed with medical record review. One cohort included patients aged ≥40 years with breast or prostate cancer or multiple myeloma; the other cohort included men aged ≥60 years and women ≥50 years with osteoporosis. For each cohort, we calculated sex- and age-standardized incidence of ONJ by exposure to oral bisphosphonates and intravenous bisphosphonates. In the cancer cohort (n = 46 542), sex- and age-standardized incidence of ONJ (n = 26 probable or possible cases) adjusted for abstraction proportion was 0.29 per 1000 person-years (95% confidence interval [CI], 0.07-0.52) among those unexposed to bisphosphonates and 5.3 (95%CI, 1.9-8.7) after intravenous bisphosphonate use. Controlling for covariates, the rate ratio for intravenous use versus no use was 8.8 (95%CI, 2.0-38). Patients with multiple myeloma had a rate 4.5 times that of patients with breast cancer. In the osteoporosis cohort (n = 31 244), sex- and age-standardized ONJ (n = 11 probable or possible cases) incidence was 0.26 per 1000 person-years (95%CI, 0.06-0.47) among those unexposed to bisphosphonate and 0.15 (95%CI, 0.00-0.36) after oral bisphosphonate use. Among patients with selected cancers, incidence of ONJ was higher among those with multiple myeloma and users of intravenous bisphosphonates.

The outcomes of conservative and surgical treatment of stage 2 bisphosphonate-related osteonecrosis of the jaws: a case series

The purpose of the current retrospective chart review is to describe the outcomes of conservative or surgical treatment of stage 2 bisphosphonate-related osteonecrosis of the jaws (BRONJ). 14 charts (mean patient age 69.07±10.37 years) describing 19 BRONJ stage 2 sites were identified. According to the treatment protocol, all patients received conservative treatment. Surgical treatment was delivered only to sites that did not respond to conservative treatment. Conservative treatment alone was delivered to 11 sites in 8 patients (mean postoperative follow-up 17.6±9.4 months). Surgical treatment was delivered to 8 sites in 6 patients (mean postoperative follow-up 10.0±6.1 months). Bisphosphonate exposure ranged from 1 to 8 years. In most cases, tooth extractions and wearing dentures were reported as triggers for BRONJ. At the last follow-up, BRONJ stage 0 was noted in 7 sites that received conservative treatment and 5 sites that received surgical treatment. Within the limitations of the current chart review, the results showed that although conservative treatment for BRONJ stage 2 can provide favourable outcomes, surgical treatment represents a suitable alternative in non-responsive cases.

Bisphosphonate-Related Osteonecrosis of the Jaw in Patients With Oral Bisphosphonate Exposure: Clinical Course and Outcomes

To characterize the spectrum and outcomes of bisphosphonate-related osteonecrosis of the jaw (BRONJ) occurring with oral bisphosphonate therapy. We assembled a retrospective cohort of patients who had developed oral BRONJ according to the 2009 American Association of Oral and Maxillofacial Surgeons criteria and received care within Kaiser Permanente, Northern California, during 2004 to 2011. Patients with intravenous bisphosphonate exposure were excluded. The demographic factors, comorbidities, pharmacologic exposure, maxillofacial findings, and outcomes were ascertained from the clinical and radiologic records. We identified 30 cases of oral BRONJ (median age 77 years, 87% women). All had received oral bisphosphonate for osteoporosis/osteopenia (median duration 4.4 years, interquartile range 1.9 to 6.6). More than one half (57%) had comorbidities or relevant drug exposure, including rheumatoid arthritis, diabetes, glucocorticoid therapy, and disease-modifying antirheumatic medications. Extractions preceded BRONJ in 17 patients and trauma in 3; 10 developed BRONJ spontaneously. Overall, 83% had healed within 3 to 52 months, although the relative rate of healing varied by antecedent factor and/or the presence of comorbid conditions/exposures. Nearly all patients with trauma-related and spontaneous BRONJ healed within 1 year (median 7.0 and 7.5 months, respectively) compared with those developing BRONJ after extraction, in whom the median time to healing was 18 months (P < .0001). Patients with relevant comorbidities had a lower probability of healing (P = .0002) and a longer median time to healing (20 months) than patients without comorbidities (7.5 months). We found that postextraction patients and those with comorbid conditions/exposures showed refractory BRONJ with prolonged healing times. Practitioners should be aware that the BRONJ clinical course and outcome varies depending on the antecedent factor and comorbidity status.

Osteonecrosis of the Jaws Unrelated to Bisphosphonate Exposure: A Series of 4 Cases

Osteonecrosis of the jaws (ONJ) is an entity that has received much attention in recent years because of multiple case reports of exposed bone in patients with a history of bisphosphonate (BP) exposure. The term ONJ generally means death of bone without implying specific causation. The American Association of Oral and Maxillofacial Surgeons gives 3 criteria for the diagnosis of BP-related ONJ: 1) The patient must have a history of BP exposure. 2) The patient ust have an area of exposed bone in the maxillofaial region that has persisted for greater than 8 weeks. ) The patient must not have a history of radiation to he head and neck region. In our institutions, over the last year, we have had 4 patients referred for management of areas of exposed bone that have been refractory to conservative

“Atypical femoral fractures” during bisphosphonate exposure in adult hypophosphatasia

We report a 55-year-old woman who suffered atypical subtrochanteric femoral fractures (ASFFs) after 4 years of exposure to alendronate and then zolendronate given for "osteoporosis." Before alendronate treatment, she had low bone mineral density. After several months of therapy, metatarsal stress fractures began. Bisphosphonate (BP) administration was stopped following the ASFFs, and the adult form of hypophosphatasia (HPP) was diagnosed from low serum alkaline phosphatase (ALP) activity, high endogenous levels of two natural substrates for the "tissue-nonspecific" isoenzyme of ALP (TNSALP), and a heterozygous mutation within the gene that encodes this enzyme. Experience with other HPP families showed that her mutation (Arg71His) with a second defective TNSALP allele can cause severe HPP in infancy, and when heterozygous can cause mild HPP featuring premature loss of deciduous teeth in children. Because the skeletal disease of HPP results from extracellular accumulation of the TNSALP substrate inorganic pyrophosphate (PPi) and its inhibitory effect on mineralization, perhaps HPP patients or carriers will have adverse effects from BPs. BPs are analogues of PPi and can suppress bone turnover but also deactivate TNSALP. Our report is the first of BP exposure preceding ASFFs in adult HPP. To explore a potential role for TNSALP deactivation in ASFFs, mutation analysis of TNSALP should be studied in a cohort of these patients. Meanwhile, clinicians must suspect HPP when clinical or laboratory clues include premature loss of primary dentition, pseudofractures or recurrent poorly healing metatarsal stress fractures, a family history suggestive of HPP, or low serum ALP activity. If HPP is documented, BP treatment might be avoided. To establish the diagnosis of HPP, assays for two natural substrates for TNSALP and TNSALP mutation analysis are available in commercial laboratories. With positive findings, radiological or bone biopsy evidence of acquired osteomalacia would indicate the adult form of this inborn-error-of-metabolism.

Impact of dental care in the prevention of bisphosphonate-associated osteonecrosis of the jaw: a single-center clinical experience

Osteonecrosis of the jaw (ONJ) is associated with bisphosphonate (BP) therapy and invasive dental care. An Interdisciplinary Care Group (ICG) was created to evaluate dental risk factors and the efficacy of a preventive restorative dental care in the reduction of ONJ risk. This prospective single-center study included patients with bone metastases from solid tumors. Patients who received at least one BP infusion between October 2005 and 31 August 2009 underwent one or more ICG evaluation and regular dental examinations. We also retrospectively evaluated patients with bone metastases from solid tumors who did not undergo dental preventive measures. Of 269 patients, 211 had received at least one infusion of BP therapy: 62% were BP naive and 38% had previous BP exposure. Of these 211 patients followed for 47 months, 6 patients developed ONJ (2.8%). Of 200 patients included in the retrospective analysis, 11 patients developed ONJ (5.5%). In comparison with published ONJ rates and those extrapolated from the retrospective analysis, the observed ONJ rate in the prospective group was lower, suggesting that implementation of a preventive dental program may reduce the risk of ONJ in metastatic patients treated with i.v. BP therapy.

Zoledronate and pamidronate depress neutrophil functions and survival in mice

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been identified as a severe complication of patients previously treated with i.v. bisphosphonates. It has been noted that necrotic bone from BRONJ sites display signs of bacterial infection suggesting that an immune defect may play a role in the pathophysiology of BRONJ. Here, we have examined the effect of two potent bisphosphonates, zoledronate and pamidronate, on neutrophil function, differentiation and survival. The effect of bisphosphonates on chemotaxis, NADPH oxidase activity and neutrophil survival were assessed in vitro using bone marrow-derived primary neutrophils or in vitro differentiated haematopoetic progenitors from mice. The same parameters and the number of circulating neutrophils were quantified in neutrophils isolated from mice treated in vivo with zoledronate. In vivo recruitment of neutrophils was assessed by sodium periodate-induced peritonitis. Zoledronate and pamidronate inhibited in vitro neutrophil chemotaxis and NADPH oxidase activity in a dose-dependent manner. In vivo recruitment of neutrophils was also suppressed. Zoledronate did not affect in vitro differentiation of neutrophils but shortened their life span in a granulocyte-colony stimulating factor-dependent manner. fMLP-induced activation of RhoA activity was decreased by zoledronate treatment. Our results show that bisphosphonate exposure leads to impaired neutrophil chemotaxis, neutrophil NADPH oxidase activity and reduced circulating neutrophil counts. This work suggests that bisphosphonates have the potential to depress the innate immune system for a prolonged time, possibly contributing to the pathogenesis of BRONJ.

The use of bisphosphonates in women prior to or during pregnancy and lactation

The unique pharmacokinetics of bisphosphonates (BPs) in conjunction with their use by an increasing number of women at reproductive age has raised serious concerns about their safety during pregnancy and lactation. Bisphosphonates cross the placenta. Animal studies have shown adverse effects on both the fetus and the mother, mostly at doses much higher than those commonly used in humans. Protracted parturition, maternal mortality, embryolethality, severe general underdevelopment and marked skeletal retardation of the fetuses (increased amount of diaphyseal bone trabeculae, decreased diaphyseal length), small fetal weight and abnormal tooth growth have been observed. We conducted a thorough research of the literature in order to identify human studies concerning this issue. We identified a total of 78 cases involving fetuses whose mothers had been exposed to BPs before conception or during pregnancy, along with 7 cases of BPs exposure prior to or during lactation. The vast majority of mothers and infants did not demonstrate serious adverse effects. However, there were cases of shortened gestational age, low neonatal birth weight and transient hypocalcaemia of the newborns, while the very few reported cases of spontaneous abortions and congenital anomalies probably resulted from maternal underlying diseases and concomitant medication. The administration of bisphosphonates in pregnancy should be assessed in view of their potential hazardous effects on both mother and fetus. In cases of absolute or relative indications of BPs prior to pregnancy, close observation of the mother and the infant, especially during the first two weeks of life, is imperative for the successful outcome of pregnancy.

Mandibular fracture in a patient treated with long-term antiangiogenic therapy and previous bisphosphonate exposure

Mandibular fracture in a patient treated with long-term antiangiogenic therapy and previous bisphosphonate exposure

Oral Bisphosphonate Use Increases the Risk for Inflammatory Jaw Disease: A Cohort Study

The objective of this study was to address whether among people living in Denmark, those treated with medications to prevent osteoporosis have an increased risk for inflammatory jaw disease compared with those not treated. A historical cohort study was designed to compare the rate of inflammatory jaw-related events, ie, osteomyelitis, osteitis, periostitis, or sequestrum, between Danish patients who had been prescribed oral bisphosphonates (BP) and other drugs for the treatment of osteoporosis between 1996 and 2006 (the exposed group), and a random sample of the Danish population drawn from a nationwide registry who had not been prescribed oral BPs or other medications to treat osteoporosis (the nonexposed group). The nonexposed subjects were age- and gender-matched to the exposed subjects and randomly drawn from the general population at a ratio of 3 non-BP subjects to 1 BP subject. The primary explanatory variable was oral BP exposure status. Associations between BP treatment and inflammatory jaw events were ascertained using hazard ratios (HR) Cox proportional hazards models. The study sample was composed of 103,562 index subjects and 310,683 control subjects. After adjusting for other factors, including diabetes and chemotherapy, alendronate (HR = 3.15, 95% confidence interval 1.44-6.87) and etidronate (HR = 2.23, 95% confidence interval 1.15-4.31) were associated with an increased risk for inflammatory jaw events. There was no association between oral BP dose and risk for inflammatory jaw events. The oral BPs alendronate and etidronate were associated with an increased risk for inflammatory jaw events.

Oral Health Considerations in Older Women Receiving Oral Bisphosphonate Therapy

Recent reports of bisphosphonate-related osteonecrosis of the jaw (BRONJ) have increased awareness of oral health in patients receiving osteoporosis therapy. This study describes the demographic, oral health, and clinical characteristics of a contemporary population of women aged 50 and older undergoing oral bisphosphonate treatment who returned a mailed questionnaire pertaining to dental symptoms. The study, as previously reported, was conducted within Kaiser Permanente Northern California, a large, integrated healthcare delivery system. The cohort included 7,909 women with bisphosphonate exposure of at least 1 year, with a subset of 923 women reporting dental symptoms who underwent clinical examination. Overall, the average age was 71 ± 9; 70% were white, and 74% had at least some college education. Nearly two-thirds had received oral bisphosphonate therapy for 3 or more years. Most reported daily tooth brushing, 85% had had a dental examination in the past year, 22% reported denture use, and 6% reported moderate to severe periodontal disease. Oral healthcare patterns varied according to age and race and ethnicity. Five hundred seven (6.4%) women reported a tooth extraction in the prior year, of whom two developed BRONJ (0.4%). Tori or exostoses were found in 28% of examined participants with dental symptoms; these were predominantly in the lingual mandible and palate, with palatal BRONJ occurring in 1.6% of symptomatic participants with palatal tori. In summary, among older women with bisphosphonate exposure, oral health varied according to patient characteristics, and BRONJ occurred more frequently after tooth extraction or on palatal tori. These data support efforts to optimize oral health and to identify risk factors for BRONJ in older individuals receiving bisphosphonate drugs.

Alendronate and atrial fibrillation: a meta-analysis of randomized placebo-controlled clinical trials

SummaryIn this meta-analysis of all Merck-conducted, placebo-controlled clinical trials of alendronate, the occurrence of AF was uncommon, with most studies reporting two or fewer events. Across all studies, no clear association between overall bisphosphonate exposure and the rate of serious or non-serious AF was observed.IntroductionTo explore the incidence of atrial fibrillation (AF) and other cardiovascular endpoints in clinical trials of alendronate.MethodsAll double-blind, placebo-controlled studies of alendronate 5, 10, or 20 mg daily, 35 mg once-weekly, 35 mg twice-weekly, and 70 mg once-weekly of at least 3 months duration conducted by Merck were included in this meta-analysis. The primary method of analysis was exact Poisson regression. Estimated relative risk (RR) of alendronate versus placebo and the associated 95% confidence interval was derived from a model that included number of episodes with factors for treatment group and study and an offset parameter for number of person-years on study.ResultsOf 41 studies considered, 32 met all criteria for inclusion in the analysis (participants—9,518 alendronate, 7,773 placebo). Estimated RR for all AF events was 1.16 (95% CI = 0.87, 1.55; p = 0.33). Most trials had two or fewer AF events. The RR of AF classified as a serious adverse event was 1.25 (95% CI = 0.82, 1.93; p = 0.33), but became 0.97 (95% CI = 0.51, 1.85) when the clinical fracture cohort of the Fracture Intervention Trial was excluded, indicating that results were driven by events in that study. Estimated RRs for other cardiovascular endpoints were less than 1.ConclusionsThe incidence of atrial fibrillation was low in Merck clinical trials of alendronate and was not significantly increased in any single trial nor in the meta-analysis. Based on this analysis, alendronate use does not appear to be associated with an increased risk of atrial fibrillation.Electronic supplementary materialThe online version of this article (doi:10.1007/s00198-011-1546-9) contains supplementary material, which is available to authorized users.

Bisphosphonate Use and the Risk of Subtrochanteric or Femoral Shaft Fractures in Older Women

Osteoporosis is associated with significant morbidity and mortality. Oral bisphosphonates have become a mainstay of treatment, but concerns have emerged that long-term use of these drugs may suppress bone remodeling, leading to unusual fractures. To determine whether prolonged bisphosphonate therapy is associated with an increased risk of subtrochanteric or femoral shaft fracture. A population-based, nested case-control study to explore the association between bisphosphonate use and fractures in a cohort of women aged 68 years or older from Ontario, Canada, who initiated therapy with an oral bisphosphonate between April 1, 2002, and March 31, 2008. Cases were those hospitalized with a subtrochanteric or femoral shaft fracture and were matched to up to 5 controls with no such fracture. Study participants were followed up until March 31, 2009. The primary analysis examined the association between hospitalization for a subtrochanteric or femoral shaft fracture and duration of bisphosphonate exposure. To test the specificity of the findings, the association between bisphosphonate use and fractures of the femoral neck or intertrochanteric region, which are characteristic of osteoporotic fractures, was also examined. We identified 716 women who sustained a subtrochanteric or femoral shaft fracture following initiation of bisphosphonate therapy and 9723 women who sustained a typical osteoporotic fracture of the intertrochanteric region or femoral neck. Compared with transient bisphosphonate use, treatment for 5 years or longer was associated with an increased risk of subtrochanteric or femoral shaft fracture (adjusted odds ratio, 2.74; 95% confidence interval, 1.25-6.02). A reduced risk of typical osteoporotic fractures occurred among women with more than 5 years of bisphosphonate therapy (adjusted odds ratio, 0.76; 95% confidence interval, 0.63-0.93). Among 52,595 women with at least 5 years of bisphosphonate therapy, a subtrochanteric or femoral shaft fracture occurred in 71 (0.13%) during the subsequent year and 117 (0.22%) within 2 years. Among older women, treatment with a bisphosphonate for more than 5 years was associated with an increased risk of subtrochanteric or femoral shaft fractures; however, the absolute risk of these fractures is low.

Making a Case for Defining Osteonecrosis of the Jaw

Making a Case for Defining Osteonecrosis of the Jaw