Clodronic acid formulations available in Europe and their use in osteoporosis: a review

Clodronic Acid has Strong Inhibitory Interactions with the Urease Enzyme of Helicobacter pylori: Computer-aided Design and in vitro Confirmation

BACKGROUND

Helicobacter pylori (HP) infection could lead to various gastrointestinal diseases. Urease is the most important virulence factor of HP. It protects the bacterium against gastric acid.

OBJECTIVE

Therefore, we aimed to design urease inhibitors as drugs against HP infection.

METHODS

The DrugBank-approved library was assigned with 3D conformations and the structure of the urease was prepared. Using a re-docking strategy, the proper settings were determined for docking by PyRx and GOLD software. Virtual screening was performed to select the best inhibitory drugs based on binding affinity, FitnessScore, and binding orientation to critical amino acids of the active site. The best inhibitory drug was then evaluated by IC50 and the diameter of the zone of inhibition for bacterial growth.

RESULTS

The structures of prepared drugs were screened against urease structure using the determined settings. Clodronic acid was determined to be the best-identified drug, due to higher PyRx binding energy, better GOLD FitnessScore, and interaction with critical amino acids of urease. In vitro results were also in line with the computational data. IC50 values of Clodronic acid and Acetohydroxamic Acid (AHA) were 29.78 ± 1.13 and 47.29 ± 2.06 μg/ml, respectively. Diameters of the zones of inhibition were 18 and 15 mm for Clodronic acid and AHA, respectively.

CONCLUSION

Clodronic acid has better HP urease inhibition potential than AHA. Given its approved status, the development of a repurposed drug based on Clodronic acid would require less time and cost. Further, in vivo studies would unveil the efficacy of Clodronic acid as a urease inhibitor.

Bisphosphonates for postmenopausal osteoporosis: a network meta‐analysis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

The aim of this systematic review is to investigate the direct and indirect evidence regarding the benefits and harms of bisphosphonates in the primary and secondary prevention of osteoporotic fractures for postmenopausal women. We will perform a network meta‐analysis, which will estimate the relative effects and relative ranking of the competing interventions for the outcomes of interest.

Multidisciplinary management of osteoporotic vertebral fractures. An overview

Vertebral fractures represent the most frequent complication associated with osteoporosis. Patients harboring a vertebral fracture complain physical impairment including low back pain and spine balance alteration, i.e., kyphosis, leading to subsequent systemic complication, with an increase in morbidity and mortality risk. Different strategies are available in the management of osteoporotic vertebral fractures: medical therapy acts as a prevention strategy while surgical vertebral augmentation procedures, when correctly indicated, aim to reduce pain and to restore the physiological vertebral height. Considering the growing prevalence and incidence of this condition and its socio-economic burden, prevention, diagnosis and treatment of osteoporotic vertebral fractures are of utmost importance. Our aim is to review the current strategies for the management of osteoporotic vertebral fractures providing an integrated multidisciplinary endocrinological, radiological and neurosurgical point of view.

Bisphosphonates-much more than only drugs for bone diseases

α,α-Bisphosphonates (BPs) are well established in the treatment of bone diseases such as osteoporosis and Paget's disease. Their successful application originates from their high affinity to hydroxyapatite. While the initially appreciated features of BPs are already beneficial to many patients, recent developments have further expanded their pleiotropic applications. This review describes the background of the interactions of BPs with bone cells that form the basis of the classical treatment. A better understanding of the mechanism behind their interactions allows for the parallel application of BPs against bone cancer and metastases followed by palliative pain relief. Targeted therapy with bone-seeking BPs coupled with a diagnostic agent in one particle resulted in theranostics which is also described here. For example, in such a system, BP moieties are bound to contrast agents used in magnetic resonance imaging or radionuclides used in positron emission tomography. In addition, another example of the pleiotropic function of BPs which involves targeting the imaging agents to bone tissues accompanied by pain reduction is presented in this work.

The efficacy and safety of vertebral fracture prevention therapies in post-menopausal osteoporosis treatment: Which therapies work best? a network meta-analysis

Objectives

Osteoporosis has become an increasing concern for older people as it may potentially lead to osteoporotic fractures. This study is designed to assess the efficacy and safety of ten therapies for post-menopausal women using network meta-analysis.

Methods

We conducted a systematic search in several databases, including PubMed and Embase. A random-effects model was employed and results were assessed by the odds ratio (OR) and corresponding 95% confidence intervals (CI). Furthermore, with respect to each outcome, each intervention was ranked according to the surface under the cumulative ranking curve (SUCRA) value.

Results

With respect to preventing new vertebral fractures (NVF), all ten drugs outperformed placebo, and etidronate proved to be the most effective treatment (OR 0.24, 95% CI 0.14 to 0.39). In addition, zoledronic acid and parathyroid hormone ranked higher compared with the other drugs. With respect to preventing clinical vertebral fractures (CVF), zoledronic acid proved to be the most effective drug (OR = 0.25, 95% CI 0.08 to 0.92), with denosumab as a desirable second option (OR = 0.48, 95% CI 0.22 to 0.96), when both were compared with placebo. As for adverse events (AE) and severe adverse events (SAE), no significant difference was observed. According to SUCRA, etidronate ranked first in preventing CVF; parathyroid hormone and zoledronic acid ranked highly in preventing NVF and CVF. Raloxifene was safe with a high rank in preventing AEs and SAEs though performed unsatisfactorily in efficacy.

Conclusions

This study suggests that, taking efficacy and safety into account, parathyroid hormone and zoledronic acid had the highest probability of satisfactory performance in preventing osteoporotic fractures.

Cite this article: G. Wang, L. Sui, P. Gai, G. Li, X. Qi, X. Jiang. The efficacy and safety of vertebral fracture prevention therapies in post-menopausal osteoporosis treatment: Which therapies work best? a network meta-analysis. Bone Joint Res 2017;6:452–463. DOI: 10.1302/2046-3758.67.BJR-2016-0292.R1.

Clodronate news of efficacy in osteoporosis

Clodronate belongs to Bisphosphonates family and it has been studied especially for osteoporosis treatment, Paget's disease, osteolytic metastases, hypercalcemia malignancy and some childhood skeletal diseases. Besides the osteoporosis treatment, it has been successfully used for treating tumoral osteolysis and for bone localization of multiple myeloma, hypercalcemia malignancy, primary hyperparathyroidism, Paget's disease and algodystrophy. Filipponi study showed a statistically significant reduction of the incidence of vertebral fractures after 4 years of treatment with clodronate, intravenously administered at a dose of 200 mg every three weeks. Frediani study, published in 2003 on BONE, proved the clodronate efficacy in the prevention of fractures caused by glucocorticoid-induced osteoporosis (GIO). Clodronate doses of 800 mg/day per os and 100 mg i.m./week are substantially equivalent, because the oral absorption is about 1,9%. A higher efficacy on BMD was documented in various works, especially in cohorts of patients with a greater fracture risk, using higher doses (1600 mg per os). This has led to the hypothesis of using clodronate 200 mg i.m. formulation. Clodronate is an osteoporosis drug that can be assumed in different doses (100 mg i.m./week, clodronate 200 mg i.m. every 2 weeks) considering the risk band, identified by algorithms (FRAX o DeFRA), by BMD and by the presence of at least one risk factor. That means that it is possible to envisage a differentiated use of clodronate adapting the doses to the fracture risk and to the severity of pain symptoms, thus promoting a greater adherence to the therapy. To conclude clodronate is helpful in reducing fracture risk, is safe, well tolerated, and has a good rate cost/effectiveness in patients with fracture risk over 7% established with FRAX.

Effect of clodronate treatment on risk of fracture: a systematic review and meta-analysis

A systematic review and a meta-analysis of data of literature were performed to evaluate the efficacy of clodronate in the reduction of risk of fractures in patients with osteoporosis or tumour diseases. A systematic review was conducted to identify original articles, reviews, and any other literature report suitable for the purposes of the meta-analysis, limited to prospective randomized trials that included a placebo or an untreated control arm. The search has identified 18 trials, 13 of which in patients with cancer diseases (breast cancer and multiple myeloma were prevalent), 4 in patients with osteoporosis/low BMD, and 1 in elderly women living in community. A placebo control arm was used in 13 trials. Treatment and follow-up duration ranged from 3 months to 5 years. The meta-analysis showed that treatment with clodronate was associated with a reduction of the probability of new fractures compared with controls (OR = 0.572, 95% CI 0.465-0.704 for new vertebral fractures; OR = 0.668, 95% CI 0.494-0.905 for new non-vertebral fractures; and OR = 0.744, 95% CI 0.635-0.873 for new overall fractures in those articles where vertebral and non-vertebral new fractures were not considered separately). Similar findings were observed in the separate analysis in patients with cancer forms or osteoporosis. The results of the meta-analysis have demonstrated that clodronate is effective in reducing the risk of vertebral, non-vertebral, and overall fractures in patients with skeletal fragility.

Bilateral renal ischemia after kyphoplasty and clodronate treatment: a case report

INTRODUCTION

The most common adverse effects associated with bisphosphonates are renal toxicity, acute-phase reactions, gastrointestinal toxicity, osteonecrosis of the jaw, transitory fever and uveitis. We report a unique adverse case of vasculitis induced by clodronate.

CASE PRESENTATION

A 61-year-old Caucasian woman developed bilateral renal ischemia after kyphoplasty and clodronate treatment for lumbar vertebral fracture. Tests revealed a vasculitis due to clodronate treatment. The antithrombotic and immunosuppressive drugs allowed us to reduce the extent of the renal ischemia. In the following months the increased auto-antibodies returned to the healthy physiological range, but the chronic renal failure persisted.

CONCLUSIONS

Drug-induced vasculitis is an inflammation of blood vessels caused by the use of various pharmaceutical agents. The spectrum of drug-induced vasculitis can range from cutaneous rashes to fatal multi-organ involvement. To the best of our knowledge this is the first documented case of drug-induced vasculitis caused by clodronate in the literature. Previously, it was verified that clodronate injection could increase the pro-apoptotic action on immune cells. Further studies are necessary to clarify the role of bisphosphonates on drug-inducing vasculitis.

Microglial depletion using intrahippocampal injection of liposome-encapsulated clodronate in prolonged hypothermic cardiac arrest in rats

Trauma patients who suffer cardiac arrest (CA) from exsanguination rarely survive. Emergency preservation and resuscitation using hypothermia was developed to buy time for resuscitative surgery and delayed resuscitation with cardiopulmonary bypass (CPB), but intact survival is limited by neuronal death associated with microglial proliferation and activation. Pharmacological modulation of microglia may improve outcome following CA. Systemic injection of liposome-encapsulated clodronate (LEC) depletes macrophages. To test the hypothesis that intrahippocampal injection of LEC would attenuate local microglial proliferation after CA in rats, we administered LEC or PBS into the right or left hippocampus, respectively. After rapid exsanguination and 6min no-flow, hypothermia was induced by ice-cold (IC) or room-temperature (RT) flush. Total duration of CA was 20min. Pre-treatment (IC, RTpre) and post-treatment (RTpost) groups were studied, along with shams (cannulation only) and CPB controls. On day 7, shams and CPB groups showed neither neuronal death nor microglial activation. In contrast, the number of microglia in hippocampus in each individual group (IC, RTpre, RTpost) was decreased with LEC vs. PBS by ∼34-46% (P<0.05). Microglial proliferation was attenuated in the IC vs. RT groups (P<0.05). Neuronal death did not differ between hemispheres or IC vs. RT groups. Thus, intrahippocampal injection of LEC attenuated microglial proliferation by ∼40%, but did not alter neuronal death. This suggests that microglia may not play a pivotal role in mediating neuronal death in prolonged hypothermic CA. This novel strategy provides us with a tool to study the specific effects of microglia in hypothermic CA.

Clinical utility of clodronate in the prevention and management of osteoporosis in patients intolerant of oral bisphosphonates

Bisphosphonates have a long history in the treatment of osteoporosis and bone-related disease. This review focuses on the use of a specific nonaminobisphosphonate, clodronate, which appears to be much better tolerated than other bisphosphonates and free of high-risk contraindications. Specifically, this paper reviews its use in the prevention of osteoporosis in postmenopausal women, taking into account its tolerability profile and recent safety issues arising regarding the use of bisphosphonates.

Effects of two administration schemes of intramuscular clodronic acid on bone mineral density: a randomized, open-label, parallel-group study

BACKGROUND

Clodronic acid is a bisphosphonate used in the prevention and treatment of postmenopausal bone loss. Previous evidence suggests a direct dose-response relationship for the densitometric effect of clodronic acid. Therefore, as it is widely accepted that a reduction in the dosing frequency of bisphosphonates may improve adherence and therefore therapeutic outcomes, an increase in the interval between consecutive administrations of clodronic acid might be associated with a concomitant increase in the overall bisphosphonate dose received. However, to our knowledge, a direct comparison of the effects of intramuscular clodronic acid 100 mg once weekly with a regimen consisting of a higher dose and a longer interval between two consecutive administrations is still lacking.

OBJECTIVE

This study compared the increase in bone mineral density (BMD) achieved with two different administration schemes of intramuscular clodronic acid (100 mg once weekly and 200 mg every 2 weeks) in patients with postmenopausal osteoporosis.

STUDY DESIGN AND SETTING

This randomized, open-label, parallel-group trial was conducted in the Osteoporosis and Instrumental Diagnosis Center 'OsteoArticolar' (University of Siena, Siena, Italy) between January 2007 and December 2009.

PATIENTS

Consecutive women aged 50-80 years with postmenopausal osteoporosis, diagnosed ≥5 years prior to inclusion in the study, were eligible for participation in this study.

INTERVENTION

Patients were randomized to receive either intramuscular clodronic acid (Clasteon®) 100 mg (group A) + lidocaine (lignocaine) once weekly or intramuscular clodronic acid 100 mg + lidocaine for two consecutive days every 2 weeks (group B), for 2 years.

RESULTS

In total, 30 patients were randomized to group A and 30 patients to group B. Significant increases in mean ± SD BMD of the lumbar spine versus baseline values were observed in both groups at 1 and 2 year(s) from treatment initiation (group A - year 1: +2.8% ± 1.7%, p < 0.05; year 2: +3.5% ± 2.2%, p < 0.01; group B - year 1: +2.7% ± 2.1%, p < 0.05; year 2: +3.9% ± 2.2%, p < 0.01). Mean ± SD BMD at the femoral neck also significantly increased versus baseline in group A at both timepoints (year 1: +2.3% ± 1.9%, p < 0.05; year 2: +2.5% ± 1.9%, p < 0.05), while the increase reported in group B was significant only after 2 years of treatment (year 1: +1.9% ± 2.2%; year 2: +2.8% ± 1.8%; p < 0.05). Significant mean ± SD increases in total femur BMD were observed only in group A at 2 years (+2.4% ± 1.9, p < 0.05). No differences between study groups were reported. Two non-traumatic vertebral fractures were observed in group A (6.6%) and three in group B (10.0%). Treatment was well tolerated; mild pain at injection site was observed in three patients (one in group A, 3.3%; two in group B, 6.6%).

CONCLUSION

This randomized study suggests, for the first time to the author's knowledge, a similar effect of intramuscular clodronic acid 100 mg once weekly and 200 mg every 2 weeks (two 100 mg administrations on two consecutive days) on BMD in women with postmenopausal osteoporosis. The administration of intramuscular clodronic acid 200 mg every 2 weeks may therefore represent a new therapeutic option in the treatment of postmenopausal osteoporosis.

Current and emerging therapies for the treatment of osteoporosis

Osteoporosis represents a weakening of bone tissue due to an imbalance in the dynamic processes of bone formation and bone resorption that are continually ongoing within bone tissue. Most currently available osteoporosis therapies are antiresorptive agents. Over the past decade, bisphosphonates, notably alendronate and risedronate, have become the dominant agents with newer bisphosphonates such as ibandronate and zoledronic acid following a trend of less frequent dosing regimens. Synthetic estrogen receptor modulators (SERMs) continue to be developed as drugs that maintain the bone-protective effects of estrogen while avoiding its associated adverse side effects. Currently available agents of this class include raloxifene, the only SERM available in the United States (US), and lasofoxifene and bazedoxifene, available in Europe. Calcitonin, usually administered as a nasal spray, completes the list of currently approved antiresorptive agents, while parathyroid hormone analogs represent the only anabolic agents currently approved in both the US and Europe. Strontium ranelate is an additional agent available in Europe but not the US that has both anabolic and antiresorptive activity. New agents expected to further expand therapeutic options include denosumab, a monoclonal antibody inhibitor of the resorptive enzyme cathepsin K, which is in the final stages of Food and Drug Administration approval. Other agents in preclinical development include those targeting specific molecules of the Wnt/β-catenin pathway involved in stimulating bone formation by osteoblast cells. This review discusses the use of currently available agents as well as highlighting emerging agents expected to bring significant changes to the approach to osteoporosis therapy in the near future.

"Twice-a-month" clodronate 200 mg IM: a new dosing regimen and improved therapy adherence in the treatment of postmenopausal osteoporosis

INTRODUCTION

The identification of therapeutic strategies aimed both at preventing and treating osteoporosis and osteoporotic fractures has become increasingly important; in particular, it is essential to promote adequate patient adherence to treatment. The primary aim of this study was to evaluate the effects on lumbar and femoral bone mass density (BMD) after two different intramuscular (IM) dosing regimens of clodronate (CLD), a bisphosphonate shown to be efficacious in reducing the incidence of both vertebral and nonvertebral fractures. Secondary aims were the assessments of bone resorption markers, safety, tolerability, pain, and patient compliance.

METHODS

Sixty women with postmenopausal osteoporosis were randomized to two groups: group A (CLD 100 mg IM weekly for 12 months), and group B (CLD 200 mg IM every 2 weeks for 12 months). All patients received 1 g of calcium supplemented with 800 IU vitamin D(3), orally, once daily for 12 months Lumbar and femoral BMD, measured by DEXA Norland XR-36 (Norland Co., Fort Atkinson, WI), and bone turnover markers were assessed at baseline and at 12 months. Each patient was administered a visual analog scale of pain at baseline and after 6 and 12 months of treatment.

RESULTS

A significant increase of BMD in both groups and in both skeletal sites was observed at 12 months versus baseline. In group A (n=28), lumbar BMD increased by 3.5% and femoral BMD by 2.1%; in group B (n=32), lumbar and femoral BMD rose by 3.4% and 2.2%, respectively. No difference was observed between groups. Bone resorption markers significantly reduced from baseline. Pain significantly improved as early as after 6 months of therapy and even more after 12 months, although no significant difference between the two groups was observed. The most common side effect was pain at the injection site, particularly in group B. Six patients in group A discontinued treatment and failed adherence to the therapeutic protocol. Conversely, no patient from group B discontinued therapy.

CONCLUSION

In agreement with published data, in our two groups of patients, therapy with IM CLD at the doses of 100 mg/week and 200 mg/2 weeks was shown to be effective in increasing BMD, without differences between the two dosing regimens in all assessed efficacy parameters. Therefore, the "twice-a-month" regimen with 200 mg IM CLD may well promote an improved adherence with the same clinical efficacy and safety profile.