The role of osteoanabolic agents in the management of patients with osteoporosis.

Reducing fracture risk is the objective of osteoporosis treatment. Bone-forming osteoporosis drugs increase bone mass, restore bone microarchitecture, and reduce fracture risk more effectively than oral bisphosphonates, providing strong justification for the use of these agents as the initial therapy or after anti-remodeling agents in patients at very high risk of fracture. At the end of a 12-to-24-month course of osteoanabolic therapy, transitioning to a potent anti-remodeling agent maintains and enhances the treatment benefit. This review describes the clinical applications of osteoanabolic therapy for osteoporosis.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS/AMERICAN COLLEGE OF ENDOCRINOLOGY CLINICAL PRACTICE GUIDELINES FOR THE DIAGNOSIS AND TREATMENT OF POSTMENOPAUSAL OSTEOPOROSIS-2020 UPDATE.

Objective: The development of these guidelines is sponsored by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPGs). Methods: Recommendations are based on diligent reviews of the clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols. Results: The Executive Summary of this 2020 updated guideline contains 52 recommendations: 21 Grade A (40%), 24 Grade B (46%), 7 Grade C (14%), and no Grade D (0%). These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world care of patients. The evidence base presented in the subsequent Appendix provides relevant supporting information for the Executive Summary recommendations. This update contains 368 citations: 123 (33.5%) evidence level (EL) 1 (highest), 132 (36%) EL 2 (intermediate), 20 (5.5%) EL 3 (weak), and 93 (25%) EL 4 (lowest). New or updated topics in this CPG include: clarification of the diagnosis of osteoporosis, stratification of the patient according to high-risk and very-high-risk features, a new dual-action therapy option, and transitions from therapeutic options. Conclusion: This guideline is a practical tool for endocrinologists, physicians in general, regulatory bodies, health-related organizations, and interested laypersons regarding the diagnosis, evaluation, and treatment of post-menopausal osteoporosis. Abbreviations: 25(OH)D = 25-hydroxyvitamin D; AACE = American Association of Clinical Endocrinologists; ACE = American College of Endocrinology; AFF = atypical femoral fracture; ASBMR = American Society for Bone and Mineral Research; BEL = best evidence level; BMD = bone mineral density; BTM = bone turnover marker; CI = confidence interval; CPG = clinical practice guideline; CTX = C-terminal telopeptide type-I collagen; DXA = dual-energy X-ray absorptiometry; EL = evidence level; FDA = U.S. Food and Drug Administration; FRAX® = Fracture Risk Assessment Tool; GI = gastrointestinal; HORIZON = Health Outcomes and Reduced Incidence with Zoledronic acid ONce yearly Pivotal Fracture Trial (zoledronic acid and zoledronate are equivalent terms); ISCD = International Society for Clinical Densitometry; IU = international units; IV = intravenous; LSC = least significant change; NOF = National Osteoporosis Foundation; ONJ = osteonecrosis of the jaw; PINP = serum amino-terminal propeptide of type-I collagen; PTH = parathyroid hormone; R = recommendation; ROI = region of interest; RR = relative risk; SD = standard deviation; TBS = trabecular bone score; VFA = vertebral fracture assessment; WHO = World Health Organization.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS/AMERICAN COLLEGE OF ENDOCRINOLOGY CLINICAL PRACTICE GUIDELINES FOR THE DIAGNOSIS AND TREATMENT OF POSTMENOPAUSAL OSTEOPOROSIS- 2020 UPDATE EXECUTIVE SUMMARY.

Objective: The development of these guidelines is sponsored by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPGs). Methods: Recommendations are based on diligent reviews of the clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols. Results: The Executive Summary of this 2020 updated guideline contains 52 recommendations: 21 Grade A (40%), 24 Grade B (46%), 7 Grade C (14%), and no Grade D (0%). These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world care of patients. The evidence base presented in the subsequent Appendix provides relevant supporting information for the Executive Summary recommendations. This update contains 368 citations: 123 (33.5%) evidence level (EL) 1 (highest), 132 (36%) EL 2 (intermediate), 20 (5.5%) EL 3 (weak), and 93 (25%) EL 4 (lowest). New or updated topics in this CPG include: clarification of the diagnosis of osteoporosis, stratification of the patient according to high-risk and very-high-risk features, a new dual-action therapy option, and transitions from therapeutic options. Conclusion: This guideline is a practical tool for endocrinologists, physicians in general, regulatory bodies, health-related organizations, and interested laypersons regarding the diagnosis, evaluation, and treatment of post-menopausal osteoporosis.

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.

Western Osteoporosis Alliance Clinical Practice Series: Treat-to-Target for Osteoporosis.

Patients often start treatment to reduce fracture risk because of a bone mineral density T-score consistent with osteoporosis (≤ -2.5). Others with a T-score above -2.5 may be treated when there is a history of fragility fracture or when a fracture risk algorithm categorizes them as having a high risk for fracture. It is common to initiate therapy with a generic oral bisphosphonate, unless contraindicated, and continue therapy if the patient is responding as assessed by stability or an increase in bone mineral density. However, some patients may respond well to an oral bisphosphonate, yet remain with an unacceptably high risk for fracture. Recognition of this occurrence has led to the development of an alternative strategy: treat-to-target. This involves identifying a biological marker (treatment target) that represents an acceptable fracture risk and then initiating treatment with an agent likely to reach this target. If the patient is on a path to reaching the target with initial therapy, treatment is continued. If it appears the target will not be reached with initial therapy, treatment is changed to an agent more likely to achieve the goal.

Proceedings of the 2017 Santa Fe Bone Symposium: Insights and Emerging Concepts in the Management of Osteoporosis.

The 18th Annual Santa Fe Bone Symposium was held on August 4-5, 2017, in Santa Fe, New Mexico, USA. The symposium convenes health-care providers and clinical researchers to present and discuss clinical applications of recent advances in research of skeletal diseases. The program includes lectures, oral presentations by endocrinology fellows, case-based panel discussions, and breakout sessions on topics of interest, with emphasis on participation and interaction of all participants. Topics included the evaluation and treatment of adult survivors with pediatric bone diseases, risk assessment and management of atypical femur fractures, nonpharmacologic strategies in the care of osteoporosis, and skeletal effects of parathyroid hormone with opportunities for therapeutic intervention. Management of skeletal complications of rheumatic diseases was discussed. Insights into sequential and combined use of antiresorptive agents were presented. Individualization of patient treatment decisions when clinical practice guidelines may not be applicable was covered. Challenges and opportunities with osteoporosis drug development were discussed. There was an update on progress of Bone Health TeleECHO (Bone Health Extension for Community Healthcare Outcomes), a teleconferencing strategy for sharing knowledge and expanding capacity to deliver best-practice skeletal health care.

Diagnosis and Treatment of Osteoporosis Before and After Fracture: A Side-by-Side Analysis of Commercially Insured and Medicare Advantage Osteoporosis Patients.

BACKGROUND: Although treatment for osteoporosis is recommended by U.S. clinical guidelines, a lack of diagnosis and treatment is common among patients with osteoporotic fractures. OBJECTIVE: To determine the rates of osteoporosis diagnosis and treatment before and after various types of fractures. METHODS: This was a retrospective claims analysis using data from the Humana Medicare Advantage claims (Medicare group) and Optum Insight Clinformatics Data Mart commercial claims (Commercial group). Patients included in the study had a claim for a qualifying fracture occurring between January 2008 and December 2013 (the index fracture), were continuously enrolled in the health plan for ≥ 1 year before and after the index fracture, and were aged ≥ 65 years in the Medicare group or ≥ 50 years in the Commercial group at the time of the index fracture. Fragility fractures and osteoporosis diagnoses were identified from ICD-9-CM codes. Treatment for osteoporosis included oral and injectable therapies identified by National Drug Code numbers and Healthcare Common Procedure Coding System codes. Diagnosis and treatment rates were assessed during the 1-year periods before and after the index fracture. All analyses were conducted by fracture type (vertebral, hip, nonhip/nonvertebral [NHNV], and multiple), with stratification by age and sex. No comparisons were made between the Medicare and Commercial groups; rather, McNemar tests were used to compare prefracture versus postfracture diagnosis and treatment rates within each group. RESULTS: For inclusion in the Medicare group, 45,603 patients were identified, and 54,145 patients were identified for the Commercial group. In the prefracture period, the osteoporosis diagnosis rates ranged from 12.0% (NHNV) to 21.5% (vertebral) in the Medicare group and from 5.3% (NHNV) to 12.1% (vertebral) in the Commercial group. In the postfracture period, diagnosis rates significantly increased (P < 0.001)-and nearly doubled-for all fracture types but did not exceed 42.1% (vertebral) in the Medicare group and 27.7% (vertebral) in the Commercial group. Pre-index treatment rates were similarly low, ranging from 9.4% (hip) to 16.6% (vertebral) among Medicare patients, and 7.5% (NHNV) to 14.4% (vertebral) in Commercial patients. Osteoporosis treatment rates improved significantly in the postfracture year, ranging from 12.5% (NHNV) to 26.5% (vertebral) among Medicare patients, and 8.3% (NHNV) to 21.4% (vertebral) in Commercial patients. Larger increases in diagnosis rates and smaller increases in treatment rates were observed in stratified analyses of men and women and of different age groups, with women and older patients having higher overall rates of diagnosis and treatment before and after fracture. CONCLUSIONS: In men and women, osteoporosis diagnosis rates were low before the index fracture and improved substantially after the fracture, yet still remained low overall (under 50%). Osteoporosis treatment rates among patients experiencing a fracture were low before the index fracture and improved only minimally afterwards. DISCLOSURES: This study was funded by Merck & Co. Other than through the employer relationship disclosed here, Merck & Co. did not have a role in the study design, data collection, interpretation of the data, in writing of the manuscript, or in the decision to submit the manuscript for publication. Weaver is an employee of Merck & Co. Sajjan was an employee of Merck & Co. and owned stock in the company at the time of the study. Lewiecki has received consulting and/or speaker honoraria from Merck & Co., AbbVie, AgNovos Healthcare, Alexion Pharmaceuticals, Amgen, Eli Lilly and Company, Radius Health, Shire, and TheraNova, along with research grant support from Merck & Co., Amgen, and Eli Lilly and Company, and serves as a board member for the National Osteoporosis Foundation, the International Society for Clinical Densitometry, and the Osteoporosis Foundation of New Mexico. Harris has received consulting honoraria from Merck & Co., Alexion Pharmaceuticals, Amgen, Eli Lilly and Company, Gilead Sciences, Primus Pharmaceuticals, and Radius Health. Study concept and design were contributed by Weaver and Sajjan. Sajjan collected the data, and data interpretation was performed by all the authors. The manuscript was written and revised by Weaver, Lewiecki, and Harris.

Prevalence and Cost of Subsequent Fractures Among U.S. Patients with an Incident Fracture.

BACKGROUND: The prevalence and cost of subsequent fractures among patients with an incident fracture are not well defined. OBJECTIVE: To assess the prevalence of, and costs associated with, subsequent fractures in the year after an incident fracture. METHODS: This was a retrospective claims database analysis using data from Humana Medicare Advantage claims (Medicare group) and Optum Insight Clinformatics Data Mart commercial claims (commercial group). Patients included in the study had a claim for a qualifying fracture occurring between January 2008 and December 2013 (index fracture), were continuously enrolled in the health plan for ≥ 1 year before and after the index fracture, and were aged ≥ 65 years in the Medicare group or ≥ 50 years in the commercial group at the time of the index fracture. Subsequent fractures were identified by ICD-9-CM codes and were defined as the second fracture occurring ≥ 3 to ≤ 12 months after the index fracture (≥ 6 to ≤ 12 months for fractures at the same site as the index fracture). Rates of subsequent fractures were calculated as the number of patients who had a subsequent fracture divided by the total sample size. After propensity matching of demographic and clinical variables, we determined the total medical and pharmacy costs accrued within 1 year of the index fracture by patients with and without a subsequent fracture. Health care costs were compared between patients with and without a subsequent fracture using McNemar's test. RESULTS: A total of 45,603 patients were included in the Medicare group, and 54,145 patients were included in the commercial group. In the Medicare group, 7,604 (16.7%) patients experienced a subsequent fracture. The proportion of patients with a subsequent fracture was highest among patients with multiple index fractures (26.2%, n = 905), followed by those with hip (25.5%, n = 1,280) and vertebral (20.2%, n = 1,908) index fractures. In the commercial group, 6,256 (11.6%) patients experienced a subsequent fracture. The proportion of patients with a subsequent fracture paralleled those observed in the Medicare group: 24.5% (n = 808) in patients with multiple index fractures, 22.0% (n = 525) in those with hip fracture, and 14.5% (n = 841) in those with vertebral fracture. For vertebral, hip, and nonhip nonvertebral fractures, subsequent fractures were most frequently of the same type as the index fracture. The mean total health care cost (sum of medical and pharmacy costs) in the year following the incident fracture for the Medicare group was $27,844 and differed significantly between patients with and without a subsequent fracture ($34,897 vs. $20,790; P < 0.001). The mean total health care cost in the year following the incident fracture for the commercial group was $29,316 and also differed significantly between patients with and without a subsequent fracture ($39,501 vs. $19,131; P < 0.001). CONCLUSIONS: Among patients with an incident fracture, those who experienced a subsequent fracture in the following year had significantly higher health care costs than those who did not. A subsequent fracture is most likely to be of the same type as the initial fracture. DISCLOSURES: This study was funded by Merck & Co. Other than through the employer relationships disclosed here, Merck & Co did not have a role in the study design, data collection, interpretation of the data, in writing of the manuscript, or in the decision to submit the manuscript for publication. Weaver and Marvos are employees of Merck & Co. Sajjan was an employee of Merck & Co. and owned stock in the company at the time of the study. Lewiecki has received consulting and/or speaker honoraria from Merck, AbbVie, AgNovos Healthcare, Alexion Pharmaceuticals, Amgen, Eli Lilly and Company, Radius Health, Shire, and TheraNova. Lewiecki has received research grant support from Merck, Amgen, and Eli Lilly and Company and serves as a board member for the National Osteoporosis Foundation, the International Society for Clinical Densitometry, and the Osteoporosis Foundation of New Mexico. Harris has received consulting honoraria from Merck, Alexion Pharmaceuticals, Amgen, Eli Lilly and Company, Gilead Sciences, Primus Pharmaceuticals, and Radius Health. Study concept and design were contributed by Weave and Sajjan. Lewiecki collected the data, and data interpretation was performed by all the authors. The manuscript was written and revised by Weaver, Lewiecki, and Harris.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY CLINICAL PRACTICE GUIDELINES FOR THE DIAGNOSIS AND TREATMENT OF POSTMENOPAUSAL OSTEOPOROSIS - 2016.

ABBREVIATIONS: AACE = American Association of Clinical Endocrinologists AFF = atypical femur fracture ASBMR = American Society for Bone and Mineral Research BEL = best evidence level BMD = bone mineral density BTM = bone turnover marker CBC = complete blood count CI = confidence interval DXA = dual-energy X-ray absorptiometry EL = evidence level FDA = U.S. Food and Drug Administration FLEX = Fracture Intervention Trial (FIT) Long-term Extension FRAX® = Fracture Risk Assessment Tool GFR = glomerular filtration rate GI = gastrointestinal HORIZON = Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly IOF = International Osteoporosis Foundation ISCD = International Society for Clinical Densitometry IU = international units IV = intravenous LSC = least significant change NBHA = National Bone Health Alliance NOF = National Osteoporosis Foundation 25(OH)D = 25-hydroxy vitamin D ONJ = osteonecrosis of the jaw PINP = serum carboxy-terminal propeptide of type I collagen PTH = parathyroid hormone R = recommendation RANK = receptor activator of nuclear factor kappa-B RANKL = receptor activator of nuclear factor kappa-B ligand RCT = randomized controlled trial RR = relative risk S-CTX = serum C-terminal telopeptide SQ = subcutaneous VFA = vertebral fracture assessment WHO = World Health Organization.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY CLINICAL PRACTICE GUIDELINES FOR THE DIAGNOSIS AND TREATMENT OF POSTMENOPAUSAL OSTEOPOROSIS - 2016--EXECUTIVE SUMMARY.

ABBREVIATIONS: AACE = American Association of Clinical Endocrinologists AFF = atypical femur fracture ASBMR = American Society for Bone and Mineral Research BEL = best evidence level BMD = bone mineral density BTM = bone turnover marker CBC = complete blood count CI = confidence interval DXA = dual-energy X-ray absorptiometry EL = evidence level FDA = U.S. Food and Drug Administration FLEX = Fracture Intervention Trial (FIT) Long-term Extension FRAX(®) = Fracture Risk Assessment Tool GFR = glomerular filtration rate GI = gastrointestinal HORIZON = Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly IOF = International Osteoporosis Foundation ISCD = International Society for Clinical Densitometry IU = international units IV = intravenous LSC = least significant change NBHA = National Bone Health Alliance NOF = National Osteoporosis Foundation 25(OH)D = 25-hydroxy vitamin D ONJ = osteonecrosis of the jaw PINP = serum carboxy-terminal propeptide of type I collagen PTH = parathyroid hormone R = recommendation RANK = receptor activator of nuclear factor kappa-B RANKL = receptor activator of nuclear factor kappa-B ligand RCT = randomized controlled trial RR = relative risk S-CTX = serum C-terminal telopeptide SQ = subcutaneous VFA = vertebral fracture assessment WHO = World Health Organization.

Relationship Between Gastrointestinal Events and Compliance With Osteoporosis Therapy: An Administrative Claims Analysis of the US Managed Care Population.

PURPOSE: A large proportion of women with osteoporosis do not comply with current osteoporosis therapies, resulting in diminished therapeutic effect. Noncompliance may be due to the occurrence of gastrointestinal (GI) events during the course of therapy. The objective of this study was to estimate the rate of GI events among women taking oral bisphosphonates and to determine the association between GI events and compliance with bisphosphonate therapy. METHODS: This was a retrospective analysis of data from a US Medicare claims database (HUMANA). The study period was from January 2007 to June 2013. The index date was the date of the first oral bisphosphonate prescription (alendronate, ibandronate, or risedronate) occurring between January 2008 and June 2012. The pre- and postindex periods were the 1-year periods before and after the index date, respectively. The analysis included women 65 years of age and older who were naïve to all osteoporosis treatments before the index date. GI events included nausea/vomiting; dysphagia; esophagitis; esophageal reflux; esophageal, gastric, duodenal, and peptic ulcer; stricture, perforation, or hemorrhage of the esophagus; acute gastritis; and GI hemorrhage. GI events were assessed during the preindex period and at 3, 6, and 12 months in the postindex period. Compliance was defined as a medication possession ratio of ≥80%. The medication possession ratio was calculated as the total days׳ supply of bisphosphonate in the postindex period divided by 365 days. The association of postindex GI events with compliance was assessed using multivariate logistic regression. FINDINGS: The analysis included 37,886 women initiating oral bisphosphonate therapy. In the preindex year, 37.5% of the women experienced a GI event, and in the postindex year, 38.9% had a GI event. Patients with preindex GI events had numerically higher rates of postindex GI events than patients without preindex GI events (61.8% vs 25.1% at 12 months postindex). Patients who experienced postindex GI events were less likely to be compliant with bisphosphonate therapy, with odds of compliance of 0.76 (95% CI, 0.72-0.80) after 12 months. IMPLICATIONS: Among US women who were prescribed oral bisphosphonates, on-treatment GI events were associated with decreased compliance at 1 year.

Bone mineral density in patients with alopecia areata treated with long-term intralesional corticosteroids.

BACKGROUND: Intralesional corticosteroid injections are a common treatment for patchy alopecia areata, the most prevalent subtype of this autoimmune hair disorder. To date, no studies have examined the potential adverse effects of this therapy on bone mineral density (BMD). METHODS: In this retrospective, cross-sectional case series, 18 patients with patchy alopecia areata treated at 4- to 8-week intervals with intralesional triamcinolone acetonide for at least 20 months were evaluated for BMD using dual-energy x-ray absorptiometry (DXA). Follow-up DXA measurements were obtained in those with abnormal findings. RESULTS: Nine out of 18 patients (50%) had abnormal DXA results. Patients with the following risk factors were more likely to have abnormal BMD: age older than 50 years, body mass index less than 18.5 kg/m2, lack of weight-bearing exercise, smoking history, postmenopausal status, past stress fracture, family history of osteopenia or osteoporosis, and a cumulative intralesional triamcinolone acetonide dose of greater than 500 mg. CONCLUSION: Patients with patchy alopecia areata who receive chronic intralesional triamcinolone acetonide therapy should be counseled on preventive measures for osteoporosis and monitored for effects on BMD.

Before the breaking point: reducing the risk of osteoporotic fracture.

Osteoporosis is a major cause of morbidity in the United States, resulting in approximately 2 million fractures and contributing to 65,000 deaths annually. Organizations have published guidelines for the diagnosis and management of the disease. However, a degree of conflict exists among some of the recommendations. Several screening tools have been developed to identify fracture risk, and although the Fracture Risk Assessment tool developed by the World Health Organization has been widely adopted, other screening tests are also potentially useful. A range of medications are available for the prevention of osteoporosis in individuals who are at high risk for the disease and for the treatment of individuals who already have osteoporosis. Although some of these medications are highly effective, all have adverse-effect profiles and other caveats that require both familiarity with the characteristics of the medication and detailed knowledge of patient needs and preferences. Effective therapy is only possible with strong patient adherence to the regimen, which in turn requires that the patient have an understanding of the risks and benefits and can participate in the treatment-selection process.

Bisphosphonate therapy for osteoporosis: benefits, risks, and drug holiday.

The amino-bisphosphonates are first-line therapy for the treatment of most patients with osteoporosis, with proven efficacy to reduce fracture risk at the spine, hip, and other nonvertebral skeletal sites. Further, bisphosphonates have been associated with a significant decrease in morbidity and increase in survival. Following the use of bisphosphonates in millions of patients in clinical practice, some unexpected possible adverse effects have been reported, including osteonecrosis of the jaw, atypical femur fractures, atrial fibrillation, and esophageal cancer. Because bisphosphonates are incorporated into the skeleton and continue to exert an antiresorptive effect for a period of time after dosing is discontinued, the concept of a drug holiday has emerged, whereby the risk of adverse effects might be decreased while the patient still benefits from antifracture efficacy. Patients receiving bisphosphonates who are not at high risk for fracture are potential candidates for a drug holiday, while for those with bone mineral density in the osteoporosis range or previous history of fragility fracture, the benefits of continuing therapy probably far outweigh the risk of harm.