Update on Rare Adverse Events from Osteoporosis Therapy and Bisphosphonate Drug Holidays

Osteonecrosis: A disabling disease not to be ignored in asthma and atopic conditions

Osteonecrosis, also referred to as avascular necrosis, is a disease characterized by necrosis or death of a bone secondary to impairment in blood supply. The condition affects the epiphyseal ends of the bones such as the femur and the humerus, but it can also involve the metacarpal and metatarsal bones, the patella, the knee, the vertebrae, and the jaw. A plethora of inflammatory, autoimmune, hematological, thrombotic, and vascular diseases can lead to osteonecrosis. Corticosteroids are intimately linked to the development of osteonecrosis. The frequent use of systemic corticosteroids in patients with asthma, eczema, nasal polyposis, sinusitis, urticaria and angioedema, or anaphylaxis makes this disease of great relevance to the practicing allergist and pulmonologist. Untreated, bone necrosis leads to frustrated bone remodeling and angiogenesis, leading to subchondral fractures and collapse of the articular heads of the bones, and culminating in debilitating osteoarthritis, often requiring arthroplasty. Recent studies have shed light on the molecular mechanisms underlying osteonecrosis and on the role of glucocorticoids. The gold standard test in patients suspected of having the disease is magnetic resonance imaging scanning, with plain radiographs having a lower sensitivity and specificity. Early diagnosis and intervention are essential. The allergist should avoid the frequent use of glucocorticoids and consider early introduction of steroid-sparing alternatives for asthma or sinusitis. Smoking and alcohol ingestion need to be addressed, and the management of glucocorticoid-induced osteoporosis may be helpful. It is essential for allergists to familiarize themselves with the disease and its diagnosis and to consider early referral to an orthopedic surgeon for surgical intervention.

Local radiographic risk factors for MRONJ in osteoporotic patients undergoing tooth extraction

OBJECTIVE

To identify local radiographic risk factors for Medication-Related Osteonecrosis of the Jaws (MRONJ) in osteoporotic patients treated with antiresorptive drugs (ARD) and undergoing tooth extraction.

MATERIAL AND METHODS

Patients were included in this retrospective, longitudinal, case-control study, if having at least one administration of ARD, underwent tooth extraction(s), and had pre- and post-operative panoramic radiographs. Additionally, a matched control group was selected. Three calibrated, blinded, and independent observers assessed each tooth extraction site. Statistical analysis compared control against study group, and within the latter, sites MRONJ+ and MRONJ-.

RESULTS

In total, 120 patients (99 females/21 males) with 354 tooth extractions were included, from which nine patients (7.5%) and eleven tooth extraction sites (3.1%) developed MRONJ. When comparing control with study group, the latter showed significantly more thickened lamina dura, persistence of the alveolar socket, heterogeneous bone patterns, and sequestrum formation. In the study group, MRONJ developed significantly more in males (19%, p = 0.049), smokers (25%, p = 0.008), in the mandible (82%, p = 0.027), when identifying a radiolucent or sclerotic trabecular pattern (p = 0.004) or when extracting teeth with furcation involvement (p < 0.001), root remnants (p = 0.017), or unrestored caries lesions (p = 0.005).

CONCLUSIONS

Tooth extraction sites showing radiographic signs of chronic dental infection are prone to MRONJ.

Towards understanding how bisphosphonate-dependent alterations to nutrient canal integrity can contribute to risk for atypical femoral fractures: Biomechanical considerations and potential relationship to a real-world analogy

Bisphosphonates are a class of drugs which have shown good efficacy in the treatment of post-menopausal osteoporosis, as well as a good safety profile. However, side-effects such as risk for atypical femoral fractures (AFF) have appeared, leading to a decline in use of the drugs by many patients who would benefit from the treatment. While patient characteristics have contributed to improved understanding of risk factors, the mechanisms involved that explain AFF risk have not appeared. Recently, the possibility that the mechanism(s) involved drug-induced modification of cells of the nutrient canals of the femur and subsequent compromise in the bone matrix has been published. The present Hypothesis article builds on the concept presented earlier and expands into biomechanical considerations. An analogy of the mechanisms involved to a real-life scenario is also presented. While this analogy has limitations, consideration of the biomechanical implications of progressive alterations to defects presented by compromised nutrient canal-bone matrix also presents potential relationships with AFF risk.

Are secondary effects of bisphosphonates on the vascular system of bone contributing to increased risk for atypical femoral fractures in osteoporosis?

Osteoporosis (OP) is a bone disease which affects a number of post-menopausal females and puts many at risk for fractures. A large number of patients are taking bisphosphonates (BPs) to treat their OP and a rare complication is the development of atypical femoral fractures (AFF). No real explanations for the mechanisms underlying the basis for development of where AFF develop while on BPs has emerged. The present hypothesis will discuss the possibility that part of the risk for an AFF is a secondary effect of BPs on a subset of vascular cells in a genetically at-risk population, leading to localized deregulation of the endothelial cell (EC)-bone cell-matrix units in nutrient channels/canals of the femur and increased risk for AFF. This concept of targeting ECs is consistent with location of AFF in the femur, the bilateral risk for occurrence of AFF, and the requirement for long term exposure to the drugs.

A survey on brazilian dentists’ awareness, perception, and knowledge of bisphosphonates

Aim: The purpose of the study was to analyze the knowledge of dentists in Belo Horizonte, Brazil, about bisphosphonates and their clinical implications. Methods: A cross-sectional questionnaire-based study was conducted with a convenience sample of dentists in Belo Horizonte, in a period of 8 weeks. The questionnaire was self-applied and was structured with 10 items about the dentists’ demographic characteristics, professional profile, and knowledge about bisphosphonates. Associations in the data were analyzed by with the Fischer’s exact test with a significance level of 5%. Results: Of the 214 participating dentists, 163 (76.17%) were women, and 51 (23.83%) were men, with age ranged for 21 to 73 years (mean of 30 years) and mean of 6 years of professional activity. Nearly half (106/49.53%) reported having knowledge about bisphosphonates, and undergraduate courses were the primary source of such information (73/34.11%). Osteoporosis was the most identified indication for use (75/35.04%), although no participants correctly identified all indications. Regarding the drugs’ side effects, only three dentists (1.40%) could correctly identify all responses, with bone necrosis being recognized by the majority (88/41.12%). Sodium alendronate (54/25.23%) and sodium ibandronate (15/7.01%) were the most identified examples of bisphosphonates. Last, only nine dentists (4.20%) could identify all examples of the drugs, and their capacity was associated with self-reported knowledge (p<0.05). Conclusions: More information about bisphosphonates should be disseminated in Belo Horizonte, ideally via better approaches in local undergraduate and postgraduate courses. Until then, knowledge of the basic aspects of bisphosphonates will remain limited.

[Exogenously induced retinopathies]

Exogenously induced retinopathies can be caused by consumation of stimulating substances, systemic or ocular medications, vaccinations, light or irradiation. Some of the effects are transient, whereas other effects induce irreversible toxic reactions. Retinal damage may develop either acutely with obvious relation to the damaging cause, but often may take a long duration of repeated use of a substance or medication. External stimulants (e.g. nicotine, alcohol, poppers, methanol) are the most frequent cause of exogenously induced retinal damage. Side effects from systemic drugs (e.g. hydroxychloroquine, ethambutol, MEK-, ERK-, FLT3-, checkpoint inhibitors, didanosin, pentosanpolysulfat sodium) or intravitreally applied drugs (e.g. antibiotics, VEGF-inhibitors) are less frequent. Ocular side effects associated with vaccinations are rare. Ambient light sources induce no damaging effects on the retina. Incorrect use of technical or medical light sources (e.g. laser pointers) without adherence to safety recommendations or unshielded observation of the sun might induce permanent retinal damage. Local or external irradiation might induce retinal vascular damage resulting in radiation retinopathy.

Exogen bedingte Retinopathien

Exogen bedingte Retinopathien werden am häufigsten durch externe Stimulanzien, seltener durch unerwünschte Arzneimittelwirkungen systemisch oder intravitreal eingesetzter Medikamente und noch seltener durch Impfungen oder die Einwirkung von Lichtstrahlung verursacht. Die Kenntnis exogener Ursachen und ihre mögliche Symptomatik ist zur Prophylaxe oder zur Früherkennung schädigender Wirkungen und zur adäquaten Beratung der Patienten wichtig.

Epigenetic therapy targeting bone marrow mesenchymal stem cells for age-related bone diseases

As global aging accelerates, the prevention and treatment of age-related bone diseases are becoming a critical issue. In the process of senescence, bone marrow mesenchymal stem cells (BMSCs) gradually lose the capability of self-renewal and functional differentiation, resulting in impairment of bone tissue regeneration and disorder of bone tissue homeostasis. Alteration in epigenetic modification is an essential factor of BMSC dysfunction during aging. Its transferability and reversibility provide the possibility to combat BMSC aging by reversing age-related modifications. Emerging evidence demonstrates that epigenetic therapy based on aberrant epigenetic modifications could alleviate the senescence and dysfunction of stem cells. This review summarizes potential therapeutic targets for BMSC aging, introduces some potential approaches to alleviating BMSC aging, and analyzes its prospect in the clinical application of age-related bone diseases.

Bone health and glucocorticoid-containing lymphoma therapy - a review of risk factors and preventative measures

With survival outcomes ever improving for patients with a wide range of lymphoma histologies, the focus on reducing long-term complications of therapy has increased. Recently published, complimentary population and retrospective series have highlighted the importance of considering bone health in patients treated for lymphoma. Fracture-related events or the requirement for secondary bone prophylaxis, likely linked to glucocorticoid-induced osteoporosis (GIO) are substantial and clinically meaningful in a significant minority of patients following routinely employed steroid-containing immunochemotherapy. In this review, we describe the pathophysiology of GIO, the risk of GIO in observational front-line lymphoma studies and efficacy of prophylactic measures from several prospective clinical trials are summarized. Finally, areas of importance for future research are discussed and recommendations for GIO risk assessment and management in lymphoma are provided based on the current available literature.

Postmenopausal osteoporosis: risk evaluation and treatment options

Postmenopausal osteoporosis is a chronic progressive condition characterized by reduced bone mass and impaired bone quality, leading to an increased risk of fragility fractures. Osteoporotic fractures reduce quality of life and are associated with high morbidity, mortality and economic burden. Primary and secondary prevention interventions are always recommended starting from the premenopausal age, in women after menopause, however, it is essential to develop a long-term intervention strategy that allows to identify patients at high risk of fracture and the choice of therapy based on the estimated risk. This narrative review described the tools for layering the management approach in relation to low, high and very high fracture risk. Several medications are now available for the treatment of osteoporosis and the prevention of fractures; the knowledge of the efficacy, safety and additional benefits profile of the individual preparations allows an appropriate choice between the different drugs available and the possibility of adapting the prescription to the lifetime fracture risk spectrum. From the literature it emerges that menopausal hormone therapy (MHT), TSEC combination and SERMs can be drugs of choice to counteract postmenopausal bone loss in younger women or at low risk of fracture, while bisphosphonates and denosumab are appropriate for women with high risk or at an older age. Therapy with denosumab and anabolic agents such as teriparatide and romosozumab is particularly indicated for subjects with very high risk of fracture.