[Calcitonin as an analgesic agent: review of mechanisms of action and clinical applications]

Where are we now? Biased signalling of Class B G protein-coupled receptor-targeted therapeutics

Class B G protein-coupled receptors (GPCRs) are a subfamily of 15 peptide hormone receptors with diverse roles in physiological functions and disease pathogenesis. Over the past decade, several novel therapeutics targeting these receptors have been approved for conditions like migraine, diabetes, and obesity, many of which are ground-breaking and first-in-class. Most of these therapeutics are agonist analogues with modified endogenous peptide sequences to enhance receptor activation or stability. Several small molecule and monoclonal antibody antagonists have also been approved or are in late-stage development. Differences in the sequence and structure of these therapeutic ligands lead to distinct signalling profiles, including biased behaviour or inhibition of specific pathways. Understanding this biased pharmacology offers unique development opportunities for improving therapeutic efficacy and reducing adverse effects. This review summarises current knowledge on the ligand bias of approved class B GPCR drugs, highlights strategies to refine and exploit their pharmacological profiles, and discusses key considerations related to receptor structure, localisation, and regulation for developing new therapies.

Postamputation Pain Management

Postamputation pain is one of the most common and challenging pain conditions to treat and includes residual limb pain and phantom limb pain. Residual limb pain is present at the amputation site or proximal to the amputation site and may be caused by poor wound healing, poor prosthetic fitting, or neuropathic pain. Phantom limb pain is experienced distal to the amputation site and may be caused by maladaptive supraspinal reorganization. Treatment for post amputation pain should be multimodal and multidisciplinary, including pharmacologic agents, rehabilitation, psychosocial support, and integrative therapies. Surgical interventions including neuromodulation may be considered for refractory cases.

Assessing suicide risk in chronic pain management: a narrative review across drug classes

INTRODUCTION

Chronic pain presents a multifaceted challenge in clinical practice, necessitating a nuanced understanding of pharmacological interventions to optimize treatment outcomes. This review provides an outline of various pharmacological agents commonly used in chronic pain management and highlights their safety considerations, particularly regarding suicide risk.

AREAS COVERED

This review discusses the role of antidepressants, anticonvulsants, GABA receptor agonists, NMDA receptor antagonists, corticosteroids, cannabis and cannabinoids, bisphosphonates, calcitonin, and alpha-2 adrenergic receptor agonists in chronic pain management. It assesses their therapeutic benefits, potential for misuse, and psychiatric adverse effects, including the risk of suicide. Each pharmacological class is evaluated in terms of its efficacy, safety profile, and considerations for clinical practice. We searched peer-reviewed English literature on the topic using the MEDLINE database without time restrictions.

EXPERT OPINION

While pharmacological interventions offer promise in alleviating chronic pain, healthcare providers must carefully weigh their benefits against potential risks, including the risk of exacerbating psychiatric symptoms and increasing suicide risk. Individualized treatment approaches, close monitoring, and multidisciplinary collaboration are essential for optimizing pain management strategies while mitigating adverse effects. Ongoing research efforts are crucial for advancing our understanding of these pharmacological interventions and refining pain management practices.

Plant-derived natural medicines for the management of osteoporosis: A comprehensive review of clinical trials

Background

Osteoporosis is a chronic and systemic skeletal disease that is defined by low bone mineral density (BMD) along with an increase in bone fragility and susceptibility to fracture. This study aimed to overview clinical evidence on the use of herbal medicine for management of osteoporosis.

Methods

Electronic databases including Pubmed, Medline, Cochrane library, and Scopus were searched until November 2022 for any clinical studies on the efficacy and/or safety of plant-derived medicines in the management of osteoporosis.

Results

The search yielded 57 results: 19 on single herbs, 16 on multi-component herbal preparations, and 22 on plant-derived secondary metabolites. Risk of fracture, bone alkaline phosphatase, BMD, and specific bone biomarkers are investigated outcomes in these studies. Medicinal plants including Acanthopanax senticosus, Actaea racemosa, Allium cepa, Asparagus racemosus, Camellia sinensis, Cissus quadrangularis, Cornus mas, Nigella sativa, Olea europaea, Opuntia ficus-indica, Pinus pinaster, Trifolium pretense and phytochemicals including isoflavones, ginsenoside, Epimedium prenyl flavonoids, tocotrienols are among plant-derived medicines clinically investigated on osteoporosis. It seems that multi-component herbal preparations were more effective than single-component ones; because of the synergistic effects of their constituents. The investigated herbal medicines demonstrated their promising results in osteoporosis via targeting different pathways in bone metabolism, including balancing osteoblasts and osteoclasts, anti-inflammatory, immunomodulatory, antioxidant, and estrogen-like functions.

Conclusion

It seems that plant-derived medicines have beneficial effects on bone and may manage osteoporosis by affecting different targets and pathways involved in osteoporosis; However, Future studies are needed to confirm the effectiveness and safety of these preparations.

Calcitonin in the Treatment of Phantom Limb Pain: A Systematic Review

INTRODUCTION

Phantom limb pain (PLP) refers to pain perceived in a part of the body removed by amputation or trauma. Despite the high prevalence of PLP following amputation and the significant morbidity associated with it, robust therapeutic approaches are currently lacking. Calcitonin, a polypeptide hormone, has recently emerged as a novel analgesic with documented benefits in the treatment of several pain-related conditions.

METHODS

We present a systematic review that comprehensively evaluates the analgesic effects of calcitonin for patients with PLP. We searched MEDLINE, OLDMEDLINE, and PubMed Central databases with the key words "calcitonin" "phantom limb pain" and "phantom pain" to identify clinical studies evaluating the efficacy or effectiveness of calcitonin administration, in any form and dose, for the treatment of PLP. Additionally, Google Scholar was searched manually with the search term "calcitonin phantom limb pain". All four databases were searched from inception until 1 December 2022. The methodological quality of each included study was assessed using the Downs and Black checklist and the GRADE criteria were used to assess effect certainty and risk of bias.

RESULTS

Our search identified 4108 citations, of which six ultimately met the criteria for inclusion in the synthesis. The included articles described a mix of open-label (n = 2), prospective observational cohort (n = 1), and randomized clinical trials (n = 3). The most common treatment regimen in the current literature is a single intravenous infusion of 200 IU salmon-derived calcitonin.

CONCLUSION

The available evidence supported the use of calcitonin as either monotherapy or adjuvant therapy in the treatment of PLP during the acute phase, while the evidence surrounding calcitonin treatment in chronic PLP is heterogeneous. Given the limited treatment options for the management of PLP and calcitonin's relatively wide therapeutic index, further research is warranted to determine the role that calcitonin may play in the treatment of PLP and other pain disorders.

Osteoporosis pathogenesis and treatment: existing and emerging avenues

Osteoporotic fractures lead to increased disability and mortality in the elderly population. With the rapid increase in the aging population around the globe, more effective treatments for osteoporosis and osteoporotic fractures are urgently required. The underlying molecular mechanisms of osteoporosis are believed to be due to the increased activity of osteoclasts, decreased activity of osteoblasts, or both, which leads to an imbalance in the bone remodeling process with accelerated bone resorption and attenuated bone formation. Currently, the available clinical treatments for osteoporosis have mostly focused on factors influencing bone remodeling; however, they have their own limitations and side effects. Recently, cytokine immunotherapy, gene therapy, and stem cell therapy have become new approaches for the treatment of various diseases. This article reviews the latest research on bone remodeling mechanisms, as well as how this underpins current and potential novel treatments for osteoporosis.

The Development of Molecular Biology of Osteoporosis

Osteoporosis is one of the major bone disorders that affects both women and men, and causes bone deterioration and bone strength. Bone remodeling maintains bone mass and mineral homeostasis through the balanced action of osteoblasts and osteoclasts, which are responsible for bone formation and bone resorption, respectively. The imbalance in bone remodeling is known to be the main cause of osteoporosis. The imbalance can be the result of the action of various molecules produced by one bone cell that acts on other bone cells and influence cell activity. The understanding of the effect of these molecules on bone can help identify new targets and therapeutics to prevent and treat bone disorders. In this article, we have focused on molecules that are produced by osteoblasts, osteocytes, and osteoclasts and their mechanism of action on these cells. We have also summarized the different pharmacological osteoporosis treatments that target different molecular aspects of these bone cells to minimize osteoporosis.