Mechanisms of the analgesic effect of calcitonin on chronic pain by alteration of receptor or channel expression

The role of nitric oxide and neuroendocrine system in pain generation

Previous studies have indicated a complex interplay between the nitric oxide (NO) pain signaling pathways and hormonal signaling pathways in the body. This article delineates the role of nitric oxide signaling in neuropathic and inflammatory pain generation and subsequently discusses how the neuroendocrine system is involved in pain generation. Hormonal systems including the hypothalamic-pituitary axis (HPA) generation of cortisol, the renin-angiotensin-aldosterone system, calcitonin, melatonin, and sex hormones could potentially contribute to the generation of nitric oxide involved in the sensation of pain. Further research is necessary to clarify this relationship and may reveal therapeutic targets involving NO signaling that alleviate neuropathic and inflammatory pain.

Calcitonin (FORTICAL, MIACALCIN) for the treatment of vertebral compression fractures

Purpose of Review

Osteoporosis is a common condition affecting the musculoskeletal system. It carries with it increased risks of fracture in many areas of the body, leading to reduced quality of life, limited mobility, and other long-term implications such as chronic pain. Vertebral compression fractures are a common development in patients with osteoporosis. Current treatment options focus on reducing pain; preventative methods are somewhat limited and focus on minimizing risk factors for the development of osteoporosis. In this review, we explore the use of calcitonin (FORTICAL, MIACALCIN) to treat vertebral compression fractures (VCFs).

Recent Findings

Osteoporosis had a prevalence of more than 10% in the United States in 2010. The CDC estimates that nearly 25% of women over age 65 have findings of osteoporosis, which include low spinal bone mass. The condition is highly prevalent and, in an aging U.S. population, quite clinically relevant. Risk factors for development include advanced age, cigarette smoking, medications, reduced physical activity, and low calcium and vitamin D intake. Family history may also play a role. Diagnosis is made based on bone mineral density.Standard therapy for VCFs in osteoporosis includes analgesic medications, such as NSAIDs and biphosphonates, and surgical intervention. NSAIDs address the chronic pain that is a common long-term effect of VCFs. Biphosphonates have recently been used to attempt to halt the progression and provide prevention. Surgical interventions such as balloon kyphoplasty and vertebroplasty are typically reserved for patients who have failed other methods.Calcitonin is a peptide naturally produced by the human body, released from the parathyroid gland. It binds to osteoclasts, inhibiting them from inducing bone resorption. By relatively unknown mechanisms, it also appears to cause endorphin release and mitigate pain. Clinical data has shown safety and efficacy for exogenous calcitonin in reducing bone turnover and reducing VCF-induced pain.

Summary

Osteoporosis is a common condition that can lead to complications such as vertebral compression fractures. It can significantly impact the quality of life in many elderly Americans. There is currently no singular treatment, but calcitonin has recently been explored as a possible option for minimizing pain and reducing disease progression. Further studies are needed to understand its preventative benefits fully.

Evaluation of the efficacy of salmon calcitonin nasal spray on bone healing following open reduction and internal fixation of mandibular fractures - A randomized controlled trial

The objective of this study was to assess the efficacy of calcitonin spray on bone healing following open reduction internal fixation (ORIF) of mandibular fractures. Fourteen patients were subdivided into a study group and a control group. A standardized surgical protocol for ORIF was followed. Postoperatively, salmon calcitonin nasal spray was administered to only the study group. The outcome parameters assessed were serum osteocalcin, pain, and radiographic bone healing. Serum osteocalcin was assessed pre- and postoperatively. Postoperative pain was documented using a visual analogue scale (VAS) on the 7th, 14th, 23rd, and 30th days. An orthopantomogram was used to score fracture healing at four time intervals, as follows: 1 - absence of callus; 2 - presence of minimal callus; 3 - considerable callus; and 4 - complete fusion of fracture. Pain scores were lower for the study group, with no pain from the fifth day, while the control group produced a mean score for day 5 of 2.43 ± 0.98 (p = 0.001). Mean postoperative serum osteocalcin levels were higher for the study group (67.82 ± 8.89) compared with the control group (57.69 ± 6.22; p = 0.029). Bone healing at 12 weeks postoperatively was level 4 for 28.6% of patients in the study group and level 3 for 71.4%. In comparison, 85.7% in the control group demonstrated level 3 healing, while 14.3% remained at level 2 (p = 0.462). Within the limitations of the study, it can be concluded that intranasal salmon calcitonin spray reduces postoperative pain and facilitates fracture healing, although its economic efficiency is still to be proven.

High rates of (treated) hypothyroidism among chronic migraine patients consulting a specialized headache clinic: are we missing something?

BACKGROUND

Roughly three percent of episodic migraine patients evolve into the most burdensome chronic form of this condition every year. While some of the determinants behind this transformation are well established, others are still ill defined. Hypothyroidism is a prevalent endocrinological disorder that can both produce a secondary headache or aggravate a pre-existing primary headache disorder such as migraine.

OBJECTIVE

We aimed to re-assess the association between hypothyroidism and chronic migraine controlling for factors such as hormone replacement treatment status and bodyweight.

METHODS

We retrospectively analyzed the medical records of episodic and chronic migraine patients who consecutively consulted our headache clinic in order to determine the prevalence of adequately treated hypothyroidism in each group. Only patients receiving a stable dose regimen were included. The body mass index and other possibly confounding covariates were also collected.

RESULTS

Data from 111 migraine patients was included for analysis. Most (88.6%) of chronic migraine sufferers were overusing acute medication. Treated hypothyroidism was significantly more prevalent in chronic migraine patients (29.55%) compared to episodic migraine patients (8.96%). This association was independent of the patients' body mass index or other variables.

CONCLUSION

Alterations of neuronal metabolism, deficient calcitonin release, or focal inflammation causing local hormonal deactivation might explain why hypothyroidism, in spite of levothyroxine replacement therapy, is associated with migraine chronification. Further studies evaluating these factors are warranted.

Transdermal Delivery of Salmon Calcitonin Using a Dissolving Microneedle Array: Characterization, Stability, and In vivo Pharmacodynamics

Salmon calcitonin (sCT) is a polypeptide drug, possessing the ability to inhibit osteoclast-mediated bone resorption. Just like other bioactive macromolecules, sCT is generally administered to the patients by either injection for poor compliance or through nasal spray for low bioavailability, which limits its use as therapeutic drugs. In the present study, to overcome the limitations of the conventional routes, two new dissolving microneedle arrays (DMNAs) based on transdermal sCT delivery systems were developed, namely sCT-DMNA-1 (sCT/Dex/K90E) and sCT-DMNA-2 (sCT/Dex-Tre/K90E) with the same dimension, meeting the requirements of suitable mechanical properties. An accurate and reliable method was established to determine the needle drug loading proportion in sCT-DMNAs. The stability study exhibited that the addition of trehalose could improve the stability of sCT in DMNA under high temperature and humidity. Further, in vivo pharmacodynamic study revealed that DMNA patch could significantly enhanced relative bioavailability to approximately 70%, and the addition of trehalose was found to be beneficial for sCT transdermal delivery. Therefore, sCT-DMNA is expected to replace traditional dosage form, providing a secure, efficient, and low-pain therapeutic strategy for bone disorders.

Perioperative Pain Management Strategies in the Age of an Opioid Epidemic

According to the US Department of Health and Human Services 2016 and 2017 data, an estimated 130 people per day died from opioid-related drug overdoses; 42,249 people died from overdosing on opioids; and 2.1 million people had opioid-use disorder. Health care organizations such as the American Association of Nurse Anesthetists, the Association of periOperative Registered Nurses, the American Society of PeriAnesthesia Nurses, the American Society of Anesthesiologists, the American College of Surgeons, and the American Medical Association have information related to pain management and/or the opioid epidemic on their Web sites. It is imperative for health care providers to be cognizant of, and use low-dose opioid/opioid-free pain management therapies. This article reviews the pain process and outlines low-dose opioid/opioid-free pain management modalities.

Efficacy of calcitonin for treating acute pain associated with osteoporotic vertebral compression fracture: an updated systematic review

Objective

Acutely painful osteoporotic vertebral compression fractures are associated with hospitalization and mortality in older adults. Calcitonin may be an alternative to opioid or nonopioid analgesia for treating acute compression fracture pain in emergency and primary care settings. This review summarizes pain, function, and adverse events associated with calcitonin.

Methods

We searched MEDLINE, EMBASE, The Cochrane Library, clinical trials registries, and reference lists of included studies. Eligible studies evaluated the effect of synthetic calcitonins (salmon, eel, and human) on pain scores in adults ≥60 years old with a recent atraumatic compression fracture. Two reviewers screened studies, extracted data, and allocated bias in duplicate. A random effects meta-analysis evaluated standard mean difference (SMD) and heterogeneity (I2).

Results

Of 1,198 articles screened, 11 were included (9 in the meta-analysis). Treatment lasted from 14 days to 6 months. Pain was lower in the salmon calcitonin group (100–200 IU IM or NAS, daily) than the control group with high certainty of evidence at week 1 (SMD, -1.54; 95% confidence interval [CI], -2.02 – -1.06; I2 = 52%), representing a number needed to treat of two. The analgesic efficacy of salmon calcitonin at 4 weeks was unclear due to substantial heterogeneity. There was low certainty evidence that calcitonin did not increase the overall risk of adverse events, including nausea and vomiting (risk ratio, 2.10; 95% CI, 0.87–5.08; I2 = 47%).

Conclusions

Calcitonin is beneficial and appears safe for treating acute pain associated with compression fractures. Further studies may improve the certainty of evidence.

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

BACKGROUND AND OBJECTIVES

Calcitonin is a polypeptide hormone regulating the metabolism calcium in the body. For many years calcitonin has been used to maintain and improve bone mineral density and to reduce the fracture rate. Many studies showed that calcitonin had analgesic role in several painful circumstances. This pain-ameliorating effect is irrelevant to its osteoclastic inhibitory effect and mechanisms like altering Na+ channel and serotonin receptor expression or hypothesis including the endorphin-mediated mechanism were used to explain this effect. In this study we performed a thorough review on the role of calcitonin as an analgesic agent in different scenarios and investigated the fact that calcitonin can be a feasible medication to relieve pain.

METHOD

Many studies focused on the analgesic effect of calcitonin in several painful circumstances, including acute pains related to vertebral fractures, metastasis, migraine and reflex sympathetic dystrophy as well as neuropathic pains related to spinal injuries or diabetes, and phantom pain. Also, calcitonin was showed to be a useful additive to local anesthesia in the case of controlling postoperative pain or trigeminal neuralgia more effectively. However we faced some contradictory data for conditions like lumbar canal stenosis, complex regional pain syndrome, phantom pain and malignancies.

CONCLUSION

This study showed that calcitonin could be helpful analgesic agent in different painful situations. Calcitonin can be considered an eligible treatment for acute pains related to vertebral fractures and a feasible alternative for the treatment of the acute and chronic neuropathic pains where other medications might fail.

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

Background and objectives

Calcitonin is a polypeptide hormone regulating the metabolism of calcium in the body. For many years calcitonin has been used to maintain and improve bone mineral density and to reduce the fracture rate. Many studies showed that calcitonin had analgesic role in several painful circumstances. This pain-ameliorating effect is irrelevant to its osteoclastic inhibitory effect and mechanisms like altering Na+ channel and serotonin receptor expression or hypothesis including the endorphin-mediated mechanism were used to explain this effect. In this study we performed a thorough review on the role of calcitonin as an analgesic agent in different scenarios and investigated the fact that calcitonin can be a feasible medication to relieve pain.

Method

Many studies focused on the analgesic effect of calcitonin in several painful circumstances, including acute pains related to vertebral fractures, metastasis, migraine and reflex sympathetic dystrophy as well as neuropathic pains related to spinal injuries or diabetes, and phantom pain. Also, calcitonin was showed to be a useful additive to local anesthesia in the case of controlling postoperative pain or trigeminal neuralgia more effectively. However we faced some contradictory data for conditions like lumbar canal stenosis, complex regional pain syndrome, phantom pain and malignancies.

Conclusion

This study showed that calcitonin could be helpful analgesic agent in different painful situations. Calcitonin can be considered an eligible treatment for acute pains related to vertebral fractures and a feasible alternative for the treatment of the acute and chronic neuropathic pains where other medications might fail.

Effects of Salmon Calcitonin on the Concentrations of Monoamines in Periaqueductal Gray in Formalin Test

Background:

The receptors of salmon calcitonin, located on certain areas of the brain such as the periaqueductal gray matter, are responsible for pain modulation.

Aims:

The effects of intracerebroventricular injection of salmon calcitonin on the behavioral response to pain and on the levels of monoamines in the periaqueductal gray were explored using a biphasic animal model of pain.

Study Design:

Animal experiment.

Methods:

A total of 45 male rats were divided into four groups (n=6). Salmon calcitonin was injected into the lateral ventricle of the brain (1.5 nmol, with a volume of 5 μL). After 20 min, 2.5% formalin was subcutaneously injected into the right leg claw, and pain behavior was recorded on a numerical basis. At the time of the formalin test, the periaqueductal gray area was microdialized. High-performance liquid chromatography method was used to gauge the levels of monoamines and their metabolites.

Results:

Intracerebroventricular injections of salmon calcitonin resulted in pain reduction in the formalin test (p<0.05). The dialysate concentrations of serotonin, dopamine, norepinephrine, 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic, and 4-hydroxy-3-methoxyphenylglycol increased in the periaqueductal gray area in different phases of the formalin pain test (p<0.05).

Conclusion:

Salmon calcitonin reduced pain by increasing the concentrations of monoamines and the metabolites derived from them in the periaqueductal gray area.

Analgesic effects of calcitonin on radicular pain in male rats

Purpose

Radicular pain is a frequently observed symptom of lumbar disk herniation or lumbar spinal canal stenosis. Achieving radicular pain relief is difficult. This type of pain may progress to chronic neuropathic pain. Calcitonin (elcatonin [eCT]) has been used mainly for hypercalcemia and pain associated with osteoporosis. The purpose of this study was to investigate analgesic effects of repeated eCT administration on radicular pain in male rats and changes in mRNA-expression levels of voltage-dependent sodium channels in the dorsal root ganglion (DRG).

Methods

Seventy male Sprague-Dawley rats were used. A right L5 hemilaminectomy and an L5-L6 partial facetectomy were performed to expose the right L5 nerve root. Under a microscope, the right L5 spinal nerve root was tightly ligated extradurally with 8-0 nylon suture proximally to the DRG to cause radicular pain in rats. Mechanical hyperalgesia, thermal hyperalgesia, and analgesic effects of eCT were compared among rats with radicular pain that received eCT, those that received the vehicle, and sham rats that received the vehicle. Real-time reverse-transcription PCR was performed to measure mRNA-expression levels of tetrodotoxin-sensitive (Na_V1.3 and Na_V1.6) and tetrodotoxin-resistant (Na_V1.8 and Na_V1.9) sodium channels in the DRG.

Results

Mechanical and thermal hyperalgesic reactions occurring in rats with radicular pain significantly improved on days 5 and 9 of eCT administration, respectively. In rats with radicular pain, mRNA-expression levels of Na_V1.3, Na_V1.8, and Na_V1.9 increased. After repeated eCT administration, mRNA-expression levels of these sodium channels in rats with radicular pain improved to the same levels as in sham rats.

Conclusion

The present study demonstrated that repeated systemic eCT administration was effective for radicular pain. No serious side effects of eCT have been reported thus far. Therefore, calcitonin may be a preferred therapeutic option for patients with radicular pain or for those requiring long-term treatment.

Role of bisphosphonates in the management of acute Charcot foot

Diabetes mellitus is the most common cause of Charcot neuropathy affecting foot and ankle. Acute Charcot foot (CF) presents with a red and swollen foot in contrast to the painless deformed one of chronic CF. Enhanced osteoclastogenesis plays a central role in the pathogenesis of acute CF. Many studies have shown elevated levels of bone turnover markers in patients with acute CF confirming it. These findings have led clinicians to use anti-resorptive agents [bisphosphonates (BP), calcitonin, and denosumab] along with immobilization and offloading in acute CF patients. The maximum evidence among all anti-resorptive agents is available for BPs, although its quality is low. Pamidronate has been shown to reduce the markers of activity of CF like raised skin temperature, pain, edema, and bone turnover markers in the majority of studies. Intravenous BPs are known to cause acute phase reactions leading to flu-like illness following their first infusion, which can be ameliorated by oral acetaminophen. Alendronate is the only oral BP used in these patients. It needs to be taken on an empty stomach with a full glass of water to avoid esophagitis. The side-effects and contraindications to BPs should be kept in mind while treating acute CF patients with them.

[Effect of collagen peptides from walleye pollock skin on bone microstructure of ovariectomized rats]

Objective

To investigate the effect of collagen peptides from walleye pollock skin on the microstructure of osteoporosis model in ovariectomized rats, and to explore the feasibility of preventing and treating oste- oporosis.

Methods

Sixty adult Wistar female rats, weighing (250±10) g, were randomly divided into 5 groups (12 rats each group): normal group (group A), osteoporosis model group (group B), osteoporosis model+collagen peptides from walleye pollock skin prevention group (group C), osteoporosis model+low concentration of collagen peptides from walleye pollock skin treatment group (group D), and osteoporosis model+high concentration of collagen peptides from walleye pollock skin treatment group (group E). The rats in groups B, C, D, and E were removed bilateral ovarian to establish osteoporosis model. The rats in group C were treated with stomach perfusion of the collagen peptides from walleye pollock skin (1.0 g/kg) from 4 weeks after operation for 6 weeks; and the rats in groups D and E were treated with stomach perfusion of the collagen peptides from walleye pollock skin (0.5, 1.0 g/kg respectively) at 6 weeks after operation for 6 weeks. The rats in groups A and B were given equal volume of normal saline at the same time after operation. At 24 hours after the last administration, the femoral gray value of rats in groups A and B were measured by X-ray film; HE staining was performed on the proximal tibial bone of the left side in 4 groups; the histopathological changes of the bone were observed and the trabecular number (TN), mean trabecular plate thickness (MTPT), mean trabecular plate spacing (MTPS), trabecular bone volume (TBV), mean bone cortical thickness (MBCT) were measured; immunohistochemical staining was performed to observe the expression levels of caltitonin receptor (CTR) and interleukin 1 (IL-1).

Results

The femoral gray value of group B was significantly lower than that of group A ( t=45.130, P=0.000), which indicated that the ovariectomized rat model was successfully prepared. Histological observation showed that TN, MTPS, TBV, and MBCT in groups A, C, and E were significantly different from those in group B ( P<0.05). The histological parameters of bone tissue in group C were significantly different from those in groups D and E ( P<0.05). TN, MTPS, TBV, and MBCT in group D were significantly different from those in group A ( P<0.05); only MTPS in group E was significantly different from that in group A ( P<0.05). MTPS, TBV, and MBCT in group E were significantly different from those in group D ( P<0.05). The immunohistochemical staining showed that the levels of CTR and IL-1 in groups A, C, D, and E were lower than those in group B, in groups C and E were lower than in group D, showing significant differences ( P<0.05).

Conclusion

Collagen peptides from walleye pollock skin can improve the bone microstructure of osteoporotic rats, and its mechanism may be related to the inhibition of CTR and IL-1 expression in bone tissue, but it has not been found to prevent osteoporosis.