Management of the adverse effects associated with intravenous bisphosphonates

Current concepts and trends in the treatment of bone metastases in patients with advanced prostate cancer

Bone metastases have a major impact on quality of life and survival of patients with advanced prostate cancer. In the last decade, the development and approval of substances inhibiting the vicious cycle of bone metastases have enabled the reduction of complications caused by bone metastases in patients with castration-resistant prostate cancer. These drugs have raised awareness of the importance of skeletal-related events which in the meantime represent an important end point also in trials using agents not specifically designed for bone lesions. Second-generation antihormonal drugs such as enzalutamide or abiraterone have been shown to have a positive impact on the incidence of skeletal complications and therefore provide an important tool in the armamentarium used for treating bone metastases. Radiopharmaceuticals such as radium-223 dichloride ([223Ra]) have been demonstrated not only to reduce skeletal-related events and bone-related pain, but also to prolong overall survival, thereby being the first bone-targeting agent showing a survival benefit. As previous studies have not provided an obvious benefit of bone-targeted lesions in castration-sensitive disease, the use of these agents is not recommended. In oligometastatic prostate cancer, the role of local treatment of metastases using stereotactic radiation or radiosurgery is a matter of intense debates and may play an increasing role in the future.

Bisphosphonates in multiple myeloma: an updated network meta-analysis

BACKGROUND

Bisphosphonates are specific inhibitors of osteoclastic activity and are used in the treatment of patients with multiple myeloma (MM). While bisphosphonates are shown to be effective in reducing vertebral fractures and pain, their role in improving overall survival (OS) remains unclear. This is an update of a Cochrane review first published in 2002 and previously updated in 2010 and 2012.

OBJECTIVES

To assess the evidence related to benefits and harms associated with use of various types of bisphosphonates (aminobisphosphonates versus non-aminobisphosphonates) in the management of patients with MM. Our primary objective was to determine whether adding bisphosphonates to standard therapy in MM improves OS and progression-free survival (PFS), and decreases skeletal-related morbidity. Our secondary objectives were to determine the effects of bisphosphonates on pain, quality of life, incidence of hypercalcemia, incidence of bisphosphonate-related gastrointestinal toxicities, osteonecrosis of jaw (ONJ) and hypocalcemia.

SEARCH METHODS

We searched MEDLINE, Embase (September 2011 to July 2017) and the CENTRAL (2017, Issue 7) to identify all randomized controlled trial (RCT) in MM up to July 2017 using a combination of text and MeSH terms.

SELECTION CRITERIA

Any randomized controlled trial (RCT) comparing bisphosphonates versus placebo/no treatment/bisphosphonates and observational studies or case reports examining bisphosphonate-related ONJ in patients with MM were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors extracted the data. Data were pooled and reported as hazard ratio (HR) or risk ratio (RR) using a random-effects model. We used meta-regression to explore statistical heterogeneity. Network meta-analysis using Bayesian approach was conducted.

MAIN RESULTS

In this update, we included four new studies (601 participants), resulting in a total of 24 included studies.Twenty RCTs compared bisphosphonates with either placebo or no treatment and four RCTs involved another bisphosphonate as a comparator. The 24 included RCTs enrolled 7293 participants. Pooled results showed that there was moderate-quality evidence of a reduction in mortality with on OS from 41% to 31%, but the confidence interval is consistent with a larger reduction and small increase in mortality compared with placebo or no treatment (HR 0.90, 95% CI 0.76 to 1.07; 14 studies; 2706 participants). There was substantial heterogeneity among the included RCTs (I² = 65%) for OS. To explain this heterogeneity we performed a meta-regression assessing the relationship between bisphosphonate potency and improvement in OS, which found an OS benefit with zoledronate but limited evidence of an effect on PFS. This provided a further rationale for performing a network meta-analyses of the various types of bisphosphonates that were not compared head-to-head in RCTs. Results from network meta-analyses showed evidence of a benefit for OS with zoledronate compared with etidronate (HR 0.56, 95% CI 0.29 to 0.87) and placebo (HR 0.67, 95% CI 0.46 to 0.91). However, there was no evidence for a difference between zoledronate and other bisphosphonates.The effect of bisphosphonates on disease progression (PFS) is uncertain. Based on the HR of 0.75 (95% CI 0.57 to 1.00; seven studies; 908 participants), 47% participants would experience disease progression without treatment compared with between 30% and 47% with bisphosphonates (low-quality evidence). There is probably a similar risk of non-vertebral fractures between treatment groups (RR 1.03, 95% CI 0.68 to 1.56; six studies; 1389 participants; moderate-quality evidence). Pooled analysis demonstrated evidence for a difference favoring bisphosphonates compared with placebo or no treatment on prevention of pathological vertebral fractures (RR 0.74, 95% CI 0.62 to 0.89; seven studies; 1116 participants; moderate-quality evidence) and skeletal-related events (SREs) (RR 0.74, 95% CI 0.63 to 0.88; 10 studies; 2141 participants; moderate-quality evidence). The evidence for less pain with bisphosphonates was of very low quality (RR 0.75, 95% CI 0.60 to 0.95; eight studies; 1281 participants).Bisphosphonates may increase ONJ compared with placebo but the confidence interval is very wide (RR 4.61, 95% CI 0.99 to 21.35; P = 0.05; six studies; 1284 participants; low-quality evidence). The results from the network meta-analysis did not show any evidence for a difference in the incidence of ONJ (eight RCTs, 3746 participants) between bisphosphonates. Data from nine observational studies (1400 participants) reported an incidence of 5% to 51% with combination of pamidronate and zoledronate, 3% to 11% with zoledronate alone, and 0% to 18% with pamidronate alone.The pooled results showed no evidence for a difference in increase in frequency of gastrointestinal symptoms with the use of bisphosphonates compared with placebo or no treatment (RR 1.23, 95% CI 0.95 to 1.59; seven studies; 1829 participants; low-quality evidence).The pooled results showed no evidence for a difference in increase in frequency of hypocalcemia with the use of bisphosphonates compared with placebo or no treatment (RR 2.19, 95% CI 0.49 to 9.74; three studies; 1090 participants; low-quality evidence). The results from network meta-analysis did not show any evidence for differences in the incidence of hypocalcemia, renal dysfunction and gastrointestinal toxicity between the bisphosphonates used.

AUTHORS' CONCLUSIONS

Use of bisphosphonates in participants with MM reduces pathological vertebral fractures, SREs and pain. Bisphosphonates were associated with an increased risk of developing ONJ. For every 1000 participants treated with bisphosphonates, about one patient will suffer from the ONJ. We found no evidence of superiority of any specific aminobisphosphonate (zoledronate, pamidronate or ibandronate) or non-aminobisphosphonate (etidronate or clodronate) for any outcome. However, zoledronate was found to be better than placebo and first-generation bisposphonate (etidronate) in pooled direct and indirect analyses for improving OS and other outcomes such as vertebral fractures. Direct head-to-head trials of the second-generation bisphosphonates are needed to settle the issue if zoledronate is truly the most efficacious bisphosphonate currently used in practice.

Long-Term Bisphosphonate Therapy in Osteogenesis Imperfecta

PURPOSE OF REVIEW

Osteogenesis imperfecta (OI) is a genetic bone disorder resulting in bone fragility. It has a heterogeneous phenotype which typically includes reduced bone mass, multiple fractures, deformity, and chronic disability. Bisphosphonate treatment remains the first-line medical management, but there is still debate on aspects of its effectiveness. This review summarizes current knowledge about long-term bisphosphonate use in OI with recommendations on clinical application.

RECENT FINDINGS

Bisphosphonates increase bone mineral density, most notably of the vertebrae, and reduce fracture risk in the pediatric OI population. Gains in strength and mobility, together with the permissive effect on orthopedic surgery (e.g., in combination with intramedullary rodding) and physiotherapy, have resulted in improved quality of life for those with OI. As experience in its use continues, the risks and benefits of long-term bisphosphonate treatment in OI are slowly emerging. Patient registries containing data on genotype, phenotype, fractures, bisphosphonate treatment, orthopedic intervention, and functional outcomes are essential for systematic evaluation given the lack of large multi-centered randomized control trials.

Use of Adjuvant Bisphosphonates and Other Bone-Modifying Agents in Breast Cancer: A Cancer Care Ontario and American Society of Clinical Oncology Clinical Practice Guideline

Purpose To make recommendations regarding the use of bisphosphonates and other bone-modifying agents as adjuvant therapy for patients with breast cancer. Methods Cancer Care Ontario and ASCO convened a Working Group and Expert Panel to develop evidence-based recommendations informed by a systematic review of the literature. Results Adjuvant bisphosphonates were found to reduce bone recurrence and improve survival in postmenopausal patients with nonmetastatic breast cancer. In this guideline, postmenopausal includes patients with natural menopause or that induced by ovarian suppression or ablation. Absolute benefit is greater in patients who are at higher risk of recurrence, and almost all trials were conducted in patients who also received systemic therapy. Most studies evaluated zoledronic acid or clodronate, and data are extremely limited for other bisphosphonates. While denosumab was found to reduce fractures, long-term survival data are still required. Recommendations It is recommended that, if available, zoledronic acid (4 mg intravenously every 6 months) or clodronate (1,600 mg/d orally) be considered as adjuvant therapy for postmenopausal patients with breast cancer who are deemed candidates for adjuvant systemic therapy. Further research comparing different bone-modifying agents, doses, dosing intervals, and durations is required. Risk factors for osteonecrosis of the jaw and renal impairment should be assessed, and any pending dental or oral health problems should be dealt with prior to starting treatment. Data for adjuvant denosumab look promising but are currently insufficient to make any recommendation. Use of these agents to reduce fragility fractures in patients with low bone mineral density is beyond the scope of the guideline. Recommendations are not meant to restrict such use of bone-modifying agents in these situations. Additional information at www.asco.org/breast-cancer-adjuvant-bisphosphonates-guideline , www.asco.org/guidelineswiki , https://www.cancercareontario.ca/guidelines-advice/types-of-cancer/breast .

Design and Biological Evaluation of Delivery Systems Containing Bisphosphonates

Bisphosphonates have found application in the treatment of reoccurrence of bone diseases, breast cancer, etc. They have also been found to exhibit antimicrobial, anticancer and antimalarial activities. However, they suffer from pharmacological deficiencies such as toxicity, poor bioavailability and low intestinal adsorption. These shortcomings have resulted in several researchers developing delivery systems that can enhance their overall therapeutic effectiveness. This review provides a detailed overview of the published studies on delivery systems designed for the delivery of bisphosphonates and the corresponding in vitro/in vivo results.

Crocin inhibits RANKL-induced osteoclast formation and bone resorption by suppressing NF-κB signaling pathway activation

Crocin is a dietary compound with antioxidant and anti-inflammatory properties, but its effects on bone resorption have not been well characterized. Here we address this issue by examining the direct effects of crocin on osteoclast cells in vitro. Osteoclastogenesis was induced by RANKL (receptor activator of NF-κB ligand) in mouse bone marrow-derived macrophages in the absence or presence of crocin at various concentrations. Further, the bone resorption activity of mature osteoclast treated with crocin was assessed by pit assay. Without altering cell viability, crocin was shown to inhibit the differentiation and function of osteoclast cells in a dose-dependent manner. Mechanistically, RANKL-induced NF-κB and NFATc1 activation, the critical signaling pathways for osteoclast differentiation and function, were both repressed by crocin in bone marrow-derived macrophages. Thus, crocin suppresses osteoclastogenesis through direct inhibition of intracellular molecular pathways, which may contribute to future development of anti-bone resorption treatment.

Treatment of bone marrow edema of the talus with pulsed electromagnetic fields: outcomes in six patients

BACKGROUND

Bone marrow edema (BME) of the talus is a rare, mostly self-limiting cause of foot and ankle pain. We sought to investigate in patients with idiopathic BME of the talus the effectiveness of pulsed electromagnetic fields and to determine the effect of this therapy on magnetic resonance imaging findings.

METHODS

Six patients with BME of the talus confirmed by magnetic resonance imaging were enrolled. Pain was quantified with a visual analog scale from 0 (no pain) to 10 (the worst pain imaginable). The clinical outcome was assessed using the American Orthopaedic Foot and Ankle Society scoring system. Treatment consisted of pulsed electromagnetic field stimulation 8 h/d for 30 days. The device used generated pulses 1.3 milliseconds in duration, with a frequency of 75 Hz and a mean ± SD induced electric field of 3.5 ± 0.5 mV.

RESULTS

The mean American Orthopaedic Foot and Ankle Society score improved from 59.4 (range, 40-66) before treatment to 94 (range, 80-100) at the last follow-up. The visual analog scale score decreased significantly from 5.6 (range, 4-7) before treatment to 1 (range, 0-2) at the last follow-up. Magnetic resonance imaging showed that BME improved after 1 month of treatment and resolved completely within 3 months in 5 patients, with normal signal intensity and no signs of progression to avascular necrosis.

CONCLUSIONS

A significant reduction in BME area was associated with a significant decrease in pain within 3 months of beginning treatment.

Extravasation reactions associated with the administration of pamidronate: 11 cases (2008-2013)

Pamidronate is a bisphosphonate drug widely utilized in veterinary oncologic practice for the palliation of malignant osteolysis. Pamidronate has not been previously reported to cause tissue injury upon extravasation in dogs. The medical records of 11 client-owned dogs undergoing palliative treatment for primary bone tumors with known or suspected pamidronate extravasation reactions were reviewed. The majority of adverse events were low grade in nature, however in some cases, the reactions were severe and led to euthanasia in one instance. Time to complete resolution of lesions ranged from within several days to greater than one and a half months. Aside from the dog that was euthanized, no long-term sequelae of extravasation were identified. Treatments employed to address the reactions varied widely. Pamidronate extravasation reaction appears to be an uncommon, but potentially serious complication of intravenous administration.

Electrolyte disorders associated with the use of anticancer drugs

The use of anticancer drugs is beneficial for patients with malignancies but is frequently associated with the occurrence of electrolyte disorders, which can be hazardous and in many cases fatal. The review presents the electrolyte abnormalities that can occur with the use of anticancer drugs and provides the related mechanisms. Platinum-containing anticancer drugs induce hypomagnesemia, hypokalemia and hypocalcemia. Moreover, platinum-containing drugs are associated with hyponatremia, especially when combined with large volumes of hypotonic fluids aiming to prevent nephrotoxicity. Alkylating agents have been linked with the occurrence of hyponatremia [due to syndrome of inappropriate antidiuretic hormone secretion (SIADH)] and Fanconi's syndrome (hypophosphatemia, aminoaciduria, hypouricemia and/or glucosuria). Vinca alkaloids are associated with hyponatremia due to SIADH. Epidermal growth factor receptor monoclonal antibody inhibitors induce hypomagnesemia, hypokalemia and hypocalcemia. Other, monoclonal antibodies, such as cixutumumab, cause hyponatremia due to SIADH. Tyrosine kinase inhibitors are linked to hyponatremia and hypophosphatemia. Mammalian target of rapamycin inhibitors induce hyponatremia (due to aldosterone resistance), hypokalemia and hypophosphatemia. Other drugs such as immunomodulators or methotrexate have been also associated with hyponatremia. The administration of estrogens at high doses, streptozocin, azacitidine and suramin may induce hypophosphatemia. Finally, the drug-related tumor lysis syndrome is associated with hyperphosphatemia, hyperkalemia and hypocalcemia. The prevention of electrolyte derangements may lead to reduction of adverse events during the administration of anticancer drugs.

Hypercalcemia of malignancy and new treatment options

Hypercalcemia of malignancy affects up to one in five cancer patients during the course of their disease. It is associated with both liquid malignancies, commonly multiple myeloma, leukemia, and non-Hodgkins lymphoma and solid cancers, particularly breast and renal carcinomas as well as squamous cell carcinomas of any organ. The clinical manifestations of hypercalcemia are generally constitutional in nature and not specific to the inciting malignancy. Such physical manifestations can range from malaise to lethargy and confusion. Constipation and anorexia are common. Acute kidney injury is likely the most frequently encountered manifestation of end organ damage. Symptomatology is closely linked to both the absolute elevation of serum calcium levels and the rapidity of calcium rise. The majority of cases are humoral in etiology and related to parathyroid hormone-related protein (PTHrP). Approximately 20% of cases are the result of direct bone metastasis with extra-renal 1,25-dihydroxyvitamin D (calcitriol) and ectopic parathyroid hormone production likely accounting for less than 1% of cases. The diagnosis of hypercalcemia of malignancy is confirmed either by an elevated PTHrP or by an evidence of bone metastasis in the appropriate clinical setting. Treatment is predicated on the patient’s symptoms and absolute serum calcium level. Interventions are aimed at lowering the serum calcium concentration by inhibiting bone resorption and increasing urinary calcium excretion, the former accomplished via bisphosphonate therapy and the latter with aggressive hydration. Novel therapies for refractory disease include denosumab, a monoclonal antibody against the receptor activator of nuclear factor κB ligand, and the calcimimetic cinacalcet. Finally, anti-PTHrP antibodies have been successfully deployed in animal models of disease. Despite the efficacy of the above therapies, hypercalcemia of malignancy portends an ominous prognosis, indicating advanced and often refractory cancer with survival on the order of months.

Severe polyarthritis secondary to zolendronic acid: a case report and literature review

Intravenous zolendronic acid is an established anti-resorptive treatment for post-menopausal osteoporosis and is usually well tolerated. Common side effects, including the classical 'acute phase response', are consented for prior to treatment. However, rare but serious adverse reactions to zolendronic acid have been described. We report the case of an older patient with osteoporosis and osteoarthritis who presented within 12 hours of her first zolendronic acid infusion with evidence of a severe acute polyarthritis affecting her peripheral appendicular skeleton, in joints affected by pre-existing osteoarthritis. Despite the prevalence of osteoarthritis, this is the most severe case of polyarthritis following intravenous zolendronic acid to date and only the second reported case. We remind prescribing physicians treating patients with intravenous bisphosphonates, to bear in mind possible rare serious adverse reactions as well as common benign side effects. We postulate age-associated frailty may reduce tolerability to even milder acute phase reactions.

Is administration of trastuzumab an independent risk factor for developing osteonecrosis of the jaw among metastatic breast cancer patients under zoledronic acid treatment?

One of the most important adverse effects of zoledronic acid (ZA) is osteonecrosis of the jaw (ONJ). In previous literature, several risk factors have been identified in the development of ONJ. In this study, we aimed to determine the role of trastuzumab, an antiangiogenic agent, as an independent risk factor for the development of this serious side effect.Our study included 97 patients (mean age: 54 ± 10 years) with breast cancer, recorded in the archives of the Istanbul Florence Nightingale Breast Study Group, who received ZA therapy due to bone metastases between March 2006 and December 2013. We recorded the patients' ages, weights, duration of treatment with ZA, number of ZA infusions, dental procedures, anticancer treatments (chemotherapy, aromatase inhibitor, trastuzumab), the presence of diabetes mellitus or renal dysfunction, and smoking habits.Thirteen patients (13.40%) had developed ONJ. Among the patients with ONJ, the mean time of exposure to ZA was 41 months (range: 13-82) and the mean number of ZA infusions was 38 (range: 15-56). The duration of treatment with ZA and the use of trastuzumab were observed to be 2 factors that influenced the development of ONJ (P = 0.049 and P = 0.028, respectively).The development of ONJ under ZA treatment may be associated solely with the duration of ZA treatment and the concurrent administration of trastuzumab. These findings show that patients who are administered trastuzumab for metastatic breast cancer while undergoing ZA treatment are prone to developing ONJ. Therefore, we recommend intense clinical observation to avoid this particular condition in patients receiving ZA and trastuzumab.

Side effects of bone-targeted therapies in advanced breast cancer

In up to 75% of cases, advanced breast cancer patients eventually develop bone metastases with often debilitating skeletal-related events (SREs). Osteoclast inhibitors are commonly used as therapeutic mainstay with clinical studies showing superiority of denosumab over bisphosphonates (e.g., zoledronate) for the prevention of SREs. The present review discusses the adverse event profile of these agents, and addresses the prevention and management of untoward side effects. Adverse events associated with osteoclast inhibitors comprise osteonecrosis of the jaw and hypocalcemia. Hypocalcemia is more common with denosumab, particularly in severe renal dysfunction. During therapy, the appropriate prevention of these adverse events includes close attention to dental health, avoidance of invasive dental procedures, supplementation with calcium and vitamin D unless patients are hypercalcemic, and regular monitoring of relevant serum values. Relating to the risk of nephrotoxicity, bisphosphonates but not denosumab have been incriminated. Therefore, serum creatinine levels should be checked prior to each dose of zoledronate, and in severe renal dysfunction (creatinine clearance < 30 ml/min) zoledronate is contraindicated anyway. Acute-phase reactions are particularly linked to bisphosphonates. Consequently, if these adverse events predominate, switching to denosumab is recommended.

Osteonecrosis Related to Once-Yearly Zoledronic Acid Treatment in an Osteoporotic Patient after Dental Implant

This paper presents a case of osteonecrosis of the jaw related to zoledronic acid (5 mg) administered once yearly to treat osteoporosis. A 79-year-old woman who has been treated for osteoporosis for 5 years with 5 applications of zoledronic acid was referred for evaluation. The patient had been submitted to dental implant placement and there was no osseointegration. On clinical examination, suppuration and exposed bone on the alveolar ridge were observed. Radiographic examination revealed an osteolytic area and bone sequestration. Both clinical and radiological features were suggestive of osteonecrosis. The treatment consisted of surgery to remove the affected bone completely. The patient is asymptomatic at 9 months after surgery. Dentists and oral surgeons should be alert to the possibility of osteonecrosis related to the use of once-yearly injections of zoledronic acid for the treatment of postmenopausal osteoporosis.

Fracture during intravenous bisphosphonate treatment in a child with osteogenesis imperfecta: an argument for a more frequent, low-dose treatment regimen

BACKGROUND/AIMS

Intravenous bisphosphonate therapy is the mainstay of medical treatment in osteogenesis imperfecta (OI) and has been shown to increase bone mass, decrease bone pain, improve mobility, and reduce the incidence of fractures. Sclerotic metaphyseal lines parallel to the growth plate are seen on long bone radiographs following cyclical intravenous therapy. These areas create stress risers within the bone that may act as foci for subsequent fractures as exemplified in this clinical case.

METHODS

An 8-year-old girl with OI sustained a distal radial fracture following 3 years of treatment with 6-monthly intravenous zoledronate. Her diagnosis, response to treatment, and subsequent fracture at a sclerotic metaphyseal line is described.

RESULTS

Peripheral quantitative computer tomography was used to characterise the presence of multiple stress risers at the distal forearm. Trabecular bone mineral density fluctuated from 34 to 126% compared to neighbouring 2-mm regions.

CONCLUSION

There remain many unanswered questions about optimal bisphosphonate treatment regimens in children with OI. The formation of stress risers following intravenous bisphosphonate treatment raises the hypothesis that a more frequent and low-dose bisphosphonate regimen would provide more uniform dosing of bone in the growing child and reduce the likelihood of fractures compared to current treatment practices.

Medical treatment of breast cancer bone metastasis: from bisphosphonates to targeted drugs

Breast cancer bone metastasis causing severe morbidity is commonly encountered in daily clinical practice. It causes pain, pathologic fractures, spinal cord and other nerve compression syndromes and life threatening hypercalcemia. Breast cancer metastasizes to bone through complicated steps in which numerous molecules play roles. Metastatic cells disrupt normal bone turnover and create a vicious cycle to which treatment efforts should be directed. Bisphosphonates have been used safely for more than two decades. As a group they delay time to first skeletal related event and reduce pain, but do not prevent development of bone metastasis in patients with no bone metastasis, and also do not prolong survival. The receptor activator for nuclear factor κB ligand inhibitor denosumab delays time to first skeletal related event and reduces the skeletal morbidity rate. Radionuclides are another treatment option for bone pain. New targeted therapies and radionuclides are still under investigation. In this review we will focus on mechanisms of bone metastasis and its medical treatment in breast cancer patients.

Synthesis, characterization and in vitro evaluation of new composite bisphosphonate delivery systems

In this study, new composite bisphosphonate delivery systems were obtained from polyurethanes (PUs) and nanocrystalline hydroxyapatite (HA). The biodegradable PUs were first synthesized from poly(ε-caprolactone) diols (PCL diols), poly(ethylene adipate) diol, 1,6-hexamethylene diisocyanate, 1,4-butanediol and HA. Moreover, the PCL diols were synthesized by the ring-opening polymerization catalysed by the lipase from Candida antarctica. Next, composite drug delivery systems for clodronate were prepared. The mechanical properties of the obtained biomaterials were determined. The cytotoxicity of the synthesized polymers was tested. The preliminary results show that the obtained composites are perspective biomaterials and they can be potentially applied in the technology of implantation drug delivery systems.

Osteogenesis imperfecta: diagnosis and treatment

Osteogenesis imperfecta (OI) is a genetic bone fragility disorder characterized by low bone mass, skeletal deformity, and variable short stature. OI is predominantly caused by dominant mutations affecting type 1 collagen synthesis, with a number of other genes implicated in OI over recent years. The clinical severity of OI can vary greatly, even within families who share a common mutation. Optimal management of OI requires a multidisciplinary approach involving pediatrician, endocrinologist (bone and mineral physician), rehabilitation specialist, orthopedic surgeon, dentist, geneticist, social worker/psychologist, physiotherapist, and occupational therapist. Bisphosphonate therapy remains the mainstay of medical treatment in OI and has been shown to decrease bone pain, enhance well-being, improve muscle strength and mobility and decrease fracture incidence. Novel therapies are beginning to emerge as more is understood about the signaling pathways involved in bone formation. The following summarizes the diagnosis, genetic heterogeneity and management of OI in pediatric practice.

Bone health in breast cancer patients: a comprehensive statement by CECOG/SAKK Intergroup

Bone is the most common site of distant metastases in breast cancer that can cause severe and debilitating skeletal related events (SRE) including hypercalcemia of malignancy, pathologic fracture, spinal cord compression and the need for palliative radiation therapy or surgery to the bone. SRE are associated with substantial pain and morbidity leading to frequent hospitalization, impaired quality of life and poor prognosis. The past 25 years of research on the pathophysiology of bone metastases led to the development of highly effective treatment options to delay or prevent osseous metastases and SRE. Management of bone metastases has become an integral part of cancer treatment requiring expertise of multidisciplinary teams of medical and radiation oncologists, surgeons and radiologists in order to find an optimal treatment for each individual patient. A group of international breast cancer experts attended a Skeletal Care Academy Meeting in November 2012 in Istanbul and discussed current preventive measures and treatment options of SRE, which are summarized in this evidence-based consensus for qualified decision- making in clinical practice.

Microstructure and properties of alendronate-loaded calcium phosphate cement

Calcium phosphate cement (CPC), as an injectable bone substitute material is significant in bone defect treatment. Drugs and biological molecules are often incorporated into CPC to promote the healing of bone defects and treat some bone diseases. In this work, alendronate (ALN)-loaded CPC was prepared and the influences of the content of ALN on the setting time, microstructure of hydrate porosity, mechanical strength, in vitro drug release, rheological properties and injectability of CPC were systematically investigated. The results showed that the addition of ALN had no effect on the final hydration product of CPC. The setting time of CPC was prolonged, while the prolonging effect became weak when the larger amount of ALN was added. With the increment of ALN content, the hydroxyapatite crystals of cured CPC became smaller, and the hydrated CPC became more compact with lower porosity, which resulted in the improvement of compressive strength of CPC with a drug-loaded amount less than 1wt%. The injectability was dramatically improved due to the addition of ALN, which was corresponding to the decrease of viscosity. The thixotropy of the CPC slurry was promoted with increasing the ALN content, which could enhance the stability of the slurry. However, it was worth noting that an inverted thixotropic loop appeared when the drug content was higher than 3.0wt%. During the in vitro drug release, the initial burst release turned up for all formulations and the degree of burst release was different from each other. This work would allow advances in understanding the effect of ALN on the setting process and physical and chemical properties of CPC, and we should think over the appropriate content when adding ALN into CPC.

Pain related to cancer treatments and diagnostic procedures: a no man's land?

BACKGROUND

While guidelines are available for the management of cancer-related pain, little attention is given to the assessment and treatment of pain caused by treatments and diagnostic procedures in cancer patients.

METHODS

We evaluated the literature on pain related to cancer treatment and diagnostic procedures within a critical analysis.

RESULTS

The data available are sparse, suggesting that little attention has been directed at this important aspect of oncology. This points to potentially suboptimal patient management.

CONCLUSIONS

Appropriate studies are necessary in order to understand the incidence and appropriate management of pain, both during and/or after oncological treatments and diagnostic procedures. At the same time, Health Care Professionals should have heightened awareness of the causes and treatment of pain with the aim of anticipating and managing pain most appropriately for each individual patient. This is clearly an important component of holistic patient care before, during, and after oncological treatment.

The use of bisphosphonates in children: review of the literature and guidelines for dental management

Bisphosphonates are inhibitors of osteoclastic bone resorption with therapeutic benefit in a variety of bone disorders in both adults and children. While these agents have been routinely used in adults for the past three decades, their more recent introduction into paediatric medicine means there is a paucity of data on long-term safety and effects on dental development. There is uncertainty regarding the dental management of children treated with bisphosphonates, particularly when invasive dental procedures, such as extractions and oral surgical procedures, are required. There are limited data with which to make recommendations about the dental management of patients treated with bisphosphonates, and there are no published recommendations that specifically address paediatric patients. This paper aims to outline paediatric uses and adverse effects of bisphosphonates and present recommendations on the dental management of children receiving bisphosphonates.

Bisphosphonates: therapeutics potential and recent advances in drug delivery

CONTEXT

Bisphosphonates (BPs) are widely used for prevention and treatment of osteoporosis. BPs are known as gold standard for osteoporosis (OP) treatment due to their positive results in clinical studies. But some serious side effects are associated with BPs like gastrointestinal adverse effect i.e. esophagitis and ulcer of esophagus. Oral bioavailability (BA) of BPs ranges from 0.6 to 1% due to poor absorption through gastrointestinal tract (GIT).

OBJECTIVE

The main objective of this review is to explore the role of novel drug delivery systems (DDSs) for the delivering of BPs and minimizing the drawbacks associated with them.

METHODS

The current review is focusing on classification, mechanism of action, and limitations of BPs, and is also dwelling on the use of novel DDSs like nanoparticles, liposomes, topical, transdermal systems, implants, bisphosphonate osteotropic DDS (BP-ODDS), microspheres, and calcium phosphate cements (CPCs) for BPs. This review also gives a critically reviewed compilation of the various in vitro and in vivo studies conducted till date.

CONCLUSION

On the basis of the exhaustive literature, it has been found that the novel DDS minimizes the side effects associated with BPs and enhances the BA. The advance drug delivery has a greater impact on reducing the undesirable effects and increasing the BA of BPs.

Bisphosphonate Related Osteonecrosis of the Jaw: An Update

OBJECTIVES

The aim of this paper is to summarize different diagnostic criteria as well as probable aetiopathogenesis of bisphosphonates related osteonecrosis of the jaw.

MATERIALS AND METHODS

The electronic search of peer-reviewed journals were performed in MEDLINE (PubMed) database in order to find the relevant articles on bisphosphonates related osteonecrosis of the jaw (BP-related ONJ). The search was restricted to English language articles, published from January 2002 to May 2013. On the basis of these articles, probable aetiopathogenesis and different diagnostic criteria of BP-related ONJ were summarized.

RESULTS

BP-related ONJ is related to the development of avascular necrosis or dead jaw bones. In recent literature many given hypotheses show the aetiopathogenesis and diagnosis of BP-related ONJ which are interlinked and have multifactorial nature. Their diagnosis revolves around four main diagnostic criteria that differentiate it from other conditions which can delay bone healing.

CONCLUSIONS

Factors like potency of bisphosphonates, biology of jaw bone, antiangiogenic property of bisphosphonates and soft tissue toxicity in combination with present infection, other drugs, pre-existing pathologies, compromised immune response and dentoalveolar trauma may lead to development of BP-related ONJ.

Evaluation of socket healing in patients undergoing bisphosphonate therapy: experience of a single Institution

OBJECTIVE

To assess the clinical features of exodontias performed in cancer patients who have been receiving intravenous bisphosphonates (BPs).

STUDY DESIGN

This is a retrospective cohort study using a sample of 20 patients receiving BPs who had 62 teeth extracted. An univariate analysis was applied to calculate socket healing time (HT), comparing among exodontias performed according to cause, such as periodontal disease or caries, type of BP, and use of corticosteroid. In order to analyze the influence of each variable on HT, multiple statistical analyses were performed through logistic multiple regression.

RESULTS

From the 62 tooth extractions performed, 5 exodontias had evolved to 4 sites of bisphosphonate-related osteonecrosis of the jaws (BOJ). Of another 57 exodontias without development of BOJ, HT was significantly better for tooth extraction performed in patients receiving corticosteroid (p= .01), for tooth extracted due to caries (p= .04), and for extractions under pamidronate (p= .03). Sockets after exodontias due to periodontal diseases had OR= 5.22 (95% CI 1.73-133.66, p=0.01) for delayed HT, exodontias performed under corticosteroid use had OR=0.04 (95% CI 0.01-0.40, p<0.001), and exodontias performed under zoledronate had OR=0.31 (95% CI 0.08-1.25, p=0.10).

CONCLUSIONS

Exodontias performed in patients under BP therapy had a low rate of BOJ occurrence. Zoledronate and periodontal diseases influence delayed socket healing. Adjuvant antibiotics could be relevant procedures aimed at reducing the risk of BOJ development.

Evolution and etiopathogenesis of bisphosphonates induced osteonecrosis of the jaw

Bisphosphonates (BPs) is widely used as the first line of treatment choice for osteoporosis, Paget’s disease of bone, bone cancer metastasis and hypercalcemia of malignancy. BPs induced osteonecrosis of the jaw (ONJ) is a relatively rare but severe clinical condition cited in English literature since 2003 while exact pathogenesis of BPs induced ONJ is not known until today, but numerous hypotheses were described in recent literature that promote and interlinked the development of BPs induced ONJ. These hypotheses indicate multifactorial nature of its development and factors responsible for that are; long term administration of intravenous nitrogen containing BPs in cancer patients, biological behavior of jaw, antiangiogenic property of BPs and by soft-tissue toxicity etc., All these factors are compounded by the presence of infection that are responsible for lower the pH of the oral cavity, other drugs like administration of corticosteroid, pathologies that cause hypo-calcification of bone, compromised immune response that alters normal healing such as renal transplantation followed by long term oral BPs therapy or chronic diabetic patients receiving BPs therapy and any dentoalveolar trauma. All literature in this review article is search from PubMed, Med-know and Google search engines.

Monocytes and γδ T cells control the acute-phase response to intravenous zoledronate: insights from a phase IV safety trial

Aminobisphosphonates (NBPs) are used widely against excessive bone resorption in osteoporosis and Paget's disease as well as in metastatic bone disease and multiple myeloma. Intravenous NBP administration often causes mild to severe acute-phase responses (APRs) that may require intervention with analgesics and antipyretics and lead to treatment noncompliance and nonadherence. We here undertook a phase IV safety trial in patients with osteoporosis to investigate the APR of otherwise healthy individuals to first-time intravenous treatment with the NBP zoledronate. This study provides unique insight into sterile acute inflammatory responses in vivo, in the absence of confounding factors such as infection or cancer. Our data show that both peripheral γδ T cells and monocytes become rapidly activated after treatment with zoledronate, which ultimately determines the clinical severity of the APR. Our study highlights a key role for IFN-γ in the zoledronate-induced APR and identifies pretreatment levels of monocytes and central/memory Vγ9/Vδ2 T cells as well as their responsiveness to zoledronate in vitro as predictive risk factors for the occurrence of subclinical and clinical symptoms. These findings have diagnostic and prognostic implications for patients with and without malignancy and are relevant for Vγ9/Vδ2 T-cell-based immunotherapy approaches.

Symptomatic Hypocalcemia Associated with Zoledronic Acid Treatment for Osteoporosis: A Case Report

Intravenous bisphosphonates are widely used in the management of solid tumors, metastatic bone disease, metabolic bone diseases and hypercalcemia of malignancies. Recently, yearly intravenous injections of zoledronic acid, one of the potent nitrogen-containing bisphosphonates, have also been approved for the prevention and treatment of osteoporosis. Although infrequently observed, asymptomatic hypocalcemia mainly due to intravenous bisphosphonates has been documented. Here we report a female patient who exhibited profound symptomatic hypocalcemia after receiving intravenous zoledronic acid as treatment of postmenopausal osteoporosis. The patient was not assessed for calcium status prior to the intravenous bisphosphonate therapy, and she was later found to have severe vitamin D deficiency. To our knowledge, this is the first patient with symptomatic hypocalcemia to be reported after zoledronic acid was approved for the management of osteoporosis. We highlight the importance of evaluating calcium and vitamin D levels before initiating intravenous bisphosphonate treatment, particularly in the presence of widespread vitamin D deficiency and the likelihood of future increases in the prescription of intravenous bisphosphonates.

Biomedical applications of bisphosphonates

Since their discovery over 100 years ago, bisphosphonates have been used industrially as corrosion inhibitors and complexing agents. With the discovery of their pharmacological activity in the late 1960s, implicating their high affinity for hydroxyapatite, bisphosphonates have been employed in the treatment of bone diseases and as targeting agents for colloids and drugs. They have notably been investigated for the treatment of Paget's disease, osteoporosis, bone metastases, malignancy-associated hypercalcemia, and pediatric bone diseases. Currently, they are first-line medications for several of these diseases and are taken by millions of patients worldwide, mostly postmenopausal women. A major problem associated with their use is their low oral bioavailability. Several delivery systems have been proposed to improve their absorption and to direct them to sites other than bone tissues. Beyond their important pharmacological role, the medical applications of bisphosphonates are numerous. In addition, their metal-chelating properties have been exploited to coat and stabilize implants, nanoparticulates, and contrast agents. In this contribution, we review the pharmacological and clinical uses of bisphosphonates and highlight their novel applications in the pharmaceutical and biomedical fields.

Prospective histomorphometric and DXA evaluation of bone remodeling in imatinib-treated CML patients: evidence for site-specific skeletal effects

CONTEXT

Imatinib is a tyrosine kinase inhibitor that has been successfully used to treat Philadelphia chromosome-positive chronic myeloid leukemia (CML) and Kit(+) gastrointestinal stromal tumors. We have previously shown that imatinib therapy is associated with an increase in trabecular bone volume.

OBJECTIVE

In the present study, we performed a prospective analysis of bone indices in imatinib-treated CML patients to determine the mechanism responsible for this altered bone remodeling. DESIGN, PATIENTS, AND INTERVENTION: This study assessed the effects of high-dose (600 mg/d) imatinib on bone parameters in newly diagnosed chronic-phase Philadelphia chromosome-positive CML patients (n = 11) enrolled in the TIDEL II study. At baseline and after 6, 12, and 24 months of treatment, serum markers of bone remodeling were quantitated, dual-energy x-ray absorptiometry analysis of bone mineral density (BMD) was carried out, and a bone biopsy was collected for histological and micro-computed tomography analysis.

RESULTS

Our studies show that the increase in trabecular bone volume and trabecular thickness after imatinib treatment was associated with a significant decrease in osteoclast numbers, accompanied by a significant decrease in serum levels of a marker of osteoclast activity. In contrast, osteoblast numbers were not altered by up to 24 months of imatinib treatment. Notably, we also found that imatinib caused a site-specific decrease in BMD at the femoral neck.

CONCLUSIONS

These data suggest that imatinib therapy dysregulates bone remodeling, causing a generalized decrease in osteoclast number and activity that is not counterbalanced by a decrease in osteoblast activity, leading to increased trabecular bone volume. Further long-term investigations are required to determine the causes and consequences of the site-specific decrease in BMD at the femoral neck.

Severe toxicity with a generic formulation of zoledronic Acid: a case report

Intravenous zoledronic acid (ZOL) is an integral component for the management of patients with bone metastases, but can be associated with transient flu-like symptoms, which generally occur only with the first infusion and are typically manageable with nonprescription analgesics. A 50-year-old woman with a bone metastasis secondary to breast cancer received radiation therapy, brand-name ZOL (Zometa^®), and letrozole. During the first 3 cycles of Zometa (4 mg every 3–4 weeks), no acute adverse events were reported. For the next 2 cycles she was switched to generic ZOL and experienced severe toxicity (nausea, vomiting, extreme weakness, and incapacitating bone pain) that required hospitalization. Toxicity differences between generic ZOL and Zometa led the patient to pay additional costs for Zometa, and subsequent Zometa infusions were without incident. This is the first case report documenting a clinically significant difference between the safety profiles of a generic formulation of ZOL and brand-name Zometa.

Current approaches to bone-targeted therapy in genitourinary malignancies

Bone metastases in patients with genitourinary cancers are associated with increased risk for skeletal-related events including pathologic fractures, spinal cord compression, and the requirement for surgery or palliative radiotherapy to bone. The nitrogen-containing bisphosphonate zoledronic acid and the monoclonal antibody against RANK, denosumab, are approved for the prevention of skeletal-related events in genitourinary cancers. These agents have different mechanisms of action and pharmacokinetic profiles, and while both are effective in reducing the risk of skeletal-related events, other clinical effects differ. There is evidence for direct and indirect anticancer activity with zoledronic acid from preclinical studies and emerging data from clinical studies suggesting an effect on patient survival. Potential anticancer mechanisms include inhibition of angiogenesis, enhanced immune surveillance via stimulation of γδ T cells, and reduction of circulating tumor cells. A synergistic effect of chemotherapy plus zoledronic acid has also been suggested. Further research is ongoing regarding the roles of these antiresorptive therapies in patients with bone metastases or at high risk for malignant spread to skeletal sites.