Serotonin receptor agonists in the acute treatment of migraine: a review on their therapeutic potential

Regional distribution of unbound eletriptan and sumatriptan in the CNS and PNS in rats: implications for a potential central action

BACKGROUND

Triptans are potent 5-HT1B/1D/1F receptor agonists used in migraine therapy, thought to act through peripheral mechanisms. It remains unclear whether triptans cross the blood-brain barrier (BBB) sufficiently to stimulate central 5-HT1B/1D/1F receptors. This study investigates the disposition of eletriptan and sumatriptan in central nervous system (CNS) and peripheral nervous system (PNS) regions and predicts regional 5-HT1B/1D/1F receptor occupancies at clinically relevant concentrations.

METHODS

Using the Combinatory Mapping Approach (CMA) for regions of interest (ROI), we assessed the unbound tissue-to-plasma concentration ratio (Kp, uu, ROI) in rats at steady state across CNS (hypothalamus, brain stem, cerebellum, frontal cortex, parietal cortex, striatum, hippocampus, whole brain, and spinal cord) and PNS (trigeminal ganglion and sciatic nerve) regions. We used Kp, uu, ROI values to estimate unbound target-site concentrations and 5-HT1B/1D/1F receptor occupancies in humans.

RESULTS

We observed heterogenous triptan transport across CNS and PNS regions with the highest extent of unbound drug transport across the blood-nerve barrier in the trigeminal ganglion (Kp, uu, TG: eletriptan: 0.519, and sumatriptan: 0.923). Both drugs displayed restricted entry across the BBB (Kp, uu, whole brain: eletriptan: 0.058, and sumatriptan: 0.045) combined with high inter-regional variability. We estimated near-complete receptor occupancy in the trigeminal ganglion, while lower occupancies were observed in the whole brain, irrespective of the drug or receptor subtype. For instance, eletriptan was predicted to achieve 84% 5-HT1B receptor occupancy in the trigeminal ganglion and 37% in the whole brain at clinically relevant concentrations.

CONCLUSIONS

This study suggests that despite low BBB transport, both eletriptan and sumatriptan achieve unbound concentrations sufficient to stimulate 5-HT1B, 5-HT1D, and 5-HT1F receptors not only in the trigeminal ganglion, but also in the CNS. Further research is needed to determine whether central mechanisms contribute to triptan's antimigraine effect and/or side effects.

Acute and preventive medical treatment of cluster headache in Taiwan: A narrative review

Cluster headache (CH) is a debilitating neurological disorder characterized by severe, unilateral pain, and ipsilateral autonomic symptoms. Chronic CH is exceedingly rare in Taiwan, constituting approximately 1% of all CH cases. This narrative review provides an up-to-date overview of the acute and preventive treatment strategies for CH in Taiwan, focusing on currently available pharmacological options in the country. The treatment approach for CH in Taiwan involves a stepwise strategy. High-flow oxygen and triptan nasal sprays are the mainstays of acute treatment, providing rapid relief, and good tolerability. Transitional treatments, such as oral steroids and suboccipital steroid injections, serve as a crucial bridge between acute and long-term preventive therapies, offering temporary relief while minimizing side effects through a carefully limited duration. For preventive treatment, verapamil is the first-line option, with lithium and topiramate being the second-line alternatives. Among the calcitonin gene-related peptide (CGRP) monoclonal antibodies, galcanezumab has demonstrated efficacy in the prevention of episodic CH. Preventive treatments are personalized to individual patients, starting with low doses and close monitoring for adverse effects. Neuromodulatory therapies, such as noninvasive vagus nerve stimulation, show promise for chronic and refractory CH but have limited availability in Taiwan. In conclusion, despite the availability of various acute and preventive treatment options, unmet needs in the management of CH in Taiwan remain. In particular, increased awareness and education among healthcare professionals to improve the diagnosis and management of CH in Taiwan should be implemented.

G protein-coupled receptors (GPCRs): advances in structures, mechanisms, and drug discovery

G protein-coupled receptors (GPCRs), the largest family of human membrane proteins and an important class of drug targets, play a role in maintaining numerous physiological processes. Agonist or antagonist, orthosteric effects or allosteric effects, and biased signaling or balanced signaling, characterize the complexity of GPCR dynamic features. In this study, we first review the structural advancements, activation mechanisms, and functional diversity of GPCRs. We then focus on GPCR drug discovery by revealing the detailed drug-target interactions and the underlying mechanisms of orthosteric drugs approved by the US Food and Drug Administration in the past five years. Particularly, an up-to-date analysis is performed on available GPCR structures complexed with synthetic small-molecule allosteric modulators to elucidate key receptor-ligand interactions and allosteric mechanisms. Finally, we highlight how the widespread GPCR-druggable allosteric sites can guide structure- or mechanism-based drug design and propose prospects of designing bitopic ligands for the future therapeutic potential of targeting this receptor family.

Is calcitonin gene-related peptide (CGRP) the missing link in food histamine-induced migraine? A review of functional gut-to-trigeminovascular system connections

Calcitonin gene-related peptide (CGRP) and histamine plasma concentrations increase during migraine attacks. Both mediators are potent vasodilators, and they have been shown to reciprocally contribute to the release of each other in the trigeminovascular system, possibly driving migraine development. A high-histamine-content diet triggers migraine in patients who have histamine degradation deficiency owing to diaminooxidase (DAO) gene mutations. Therefore, studying functional links between exogenous histamine and CGRP seems promising for the understanding of diet-induced migraine generation. Notably, there is a lack of knowledge about the interplay of the enteric nervous system and the spinal/trigeminal somatosensory system with regard to CGRP and histamine. Based on background evidence, we propose that a functional interconnection between exogenous histamine and CGRP contributes to migraine development.

Calcitonin gene-related peptide antagonists in pregnancy: a disproportionality analysis in VigiBase®

BACKGROUND

Current evidence on the safety of calcitonin gene-related peptide antagonists (CGRP-A) in pregnancy for the treatment of both episodic and chronic migraine is scarce and does not yet provide definitive information. By querying VigiBase®, the World Health Organization global pharmacovigilance database, this study aimed to detect differences in the reporting frequency between CGRP-A and triptans in relation to pregnancy.

METHODS

Disproportionality analyses on de-duplicated safety reports collected in VigiBase® as of 31.05.2023 reporting exposure to CGRP-A in pregnancy with or without pregnancy outcomes. A Reporting Odds Ratio (ROR) with a 95% confidence interval (CI) was used as a measure of disproportionality and the threshold for the detection of a signal of disproportionate reporting was set with a 95% CI lower limit > 1.

FINDINGS

Four hundred sixty-seven safety reports reported exposure to CGRP-A in pregnancy, mostly originating from the United States of America (360/467, 77%), more frequently reported by patients (225/467, 48%), who were mainly females (431/467, 92%), and more frequently reported exposure to CGRP-A during pregnancy (400/467, 86%). Compared to triptans, no signals of disproportionate reporting were detected with CGRP-A either for the overall reporting of pregnancy-related safety reports (ROR 0.91, 95% CI 0.78-1.06), for the reporting of pregnancy outcomes (maternal and/or foetal/neonatal, ROR 0.54, 95% CI 0.45-0.66), or for the reporting of foetal/neonatal outcomes (ROR 0.53, 95% CI 0.41-0.68).

CONCLUSIONS

This study showed that, to date, there are no signals of increased reporting with CGRP-A compared to triptans in relation to pregnancy in VigiBase®. Future pharmacovigilance studies are needed to confirm these findings.

A Comprehensive Review of the Mechanism, Efficacy, Safety, and Tolerability of Ubrogepant in the Treatment of Migraine

Ubrogepant is an innovative medication designed for the acute treatment of migraine, a debilitating neurological condition that profoundly impairs quality of life, productivity, and social interactions. This comprehensive review assesses the efficacy, safety, tolerability, and mechanism of action of ubrogepant through a rigorous methodology, including an in-depth literature review from reputable databases like PubMed, Web of Science, Embase, Scopus, and Cochrane. Classified as a calcitonin gene-related peptide (CGRP) receptor antagonist, ubrogepant has emerged as a potential revolutionary medication for migraine treatment. CGRP is a peptide integral to migraine pathophysiology, and its blockade has demonstrated great therapeutic potential. Unlike triptans, known for their cardiovascular risks, ubrogepant lacks vasoconstrictive properties, making it a safer alternative for a broader patient population. Ubrogepant offers significant potential for pain relief, symptom reduction, and restoration of normal function during a migraine attack, and it outperforms placebo in terms of efficacy. It also presents favorable safety, with generally mild adverse drug events (ADEs), such as nausea, dizziness, and somnolence, similar to placebo effects. Consistent results from clinical trials confirm its tolerability, with minor ADEs and no safety alerts for the tested doses, indicating that ubrogepant is a safe and well-tolerated option for migraine treatment. As an effective oral medication, ubrogepant could be an alternative to traditional acute migraine treatments. Its benefits include a unique mechanism of action, rapid onset, and favorable safety profile. However, specific contraindications, such as hypersensitivity, severe hepatic impairment, concurrent use of CYP3A4 inhibitors, pregnancy or breastfeeding, and uncontrolled hypertension, require caution or avoidance of ubrogepant. Despite these limitations, ubrogepant signals a promising new direction in migraine therapeutics.

Structural studies of serotonin receptor family

Serotonin receptors, also known as 5-HT receptors, belong to the G protein-coupled receptors (GPCRs) superfamily. They mediate the effects of serotonin, a neurotransmitter that plays a key role in a wide range of functions including mood regulation, cognition and appetite. The functions of serotonin are mediated by a family of 5-HT receptors including 12 GPCRs belonging to six major families: 5-HT1, 5-HT2, 5-HT4, 5-HT5, 5-HT6 and 5-HT7. Despite their distinct characteristics and functions, these receptors' subtypes share common structural features and signaling mechanisms. Understanding the structure, functions and pharmacology of the serotonin receptor family is essential for unraveling the complexities of serotonin signaling and developing targeted therapeutics for neuropsychiatric disorders. However, developing drugs that selectively target specific receptor subtypes is challenging due to the structural similarities in their orthosteric binding sites. This review focuses on the recent advancements in the structural studies of 5-HT receptors, highlighting the key structural features of each subtype and shedding light on their potential as targets for mental health and neurological disorders (such as depression, anxiety, schizophrenia, and migraine) drugs. [BMB Reports 2023; 56(10): 527-536].

Potential analgesic effect of Foshousan oil-loaded chitosan-alginate nanoparticles on the treatment of migraine

Background: Migraine is a common neurovascular disorder with typical throbbing and unilateral headaches, causing a considerable healthcare burden on the global economy. This research aims to prepare chitosan-alginate (CS-AL) nanoparticles (NPs) containing Foshousan oil (FSSO) and investigate its potential therapeutic effects on the treatment of migraine. Methods: FSSO-loaded CS-AL NPs were prepared by using the single emulsion solvent evaporation method. Lipopolysaccharide (LPS)-stimulated BV-2 cells and nitroglycerin (NTG)-induced migraine mice were further used to explore anti-migraine activities and potential mechanisms of this botanical drug. Results: FSSO-loaded CS-AL NPs (212.1 ± 5.2 nm, 45.1 ± 6.2 mV) had a well-defined spherical shape with prolonged drug release and good storage within 4 weeks. FSSO and FSSO-loaded CS-AL NPs (5, 10, and 15 μg/mL) showed anti-inflammatory activities in LPS-treated BV-2 cells via reducing the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and nitric oxide (NO), but elevating interleukin-10 (IL-10) expressions. Moreover, FSSO-loaded CS-AL NPs (52 and 104 mg/kg) raised pain thresholds against the hot stimulus and decreased acetic acid-induced writhing frequency and foot-licking duration in NTG-induced migraine mice. Compared with the model group, calcitonin gene-related peptide (CGRP) and NO levels were downregulated, but 5-hydroxytryptamine (5-HT) and endothelin (ET) levels were upregulated along with rebalanced ET/NO ratio, and vasomotor dysfunction was alleviated by promoting cerebral blood flow (CBF) in the FSSO-loaded CS-AL NPs (104 mg/kg) group. Conclusion: FSSO-loaded CS-AL NPs could attenuate migraine via inhibiting neuroinflammation in LPS-stimulated BV-2 cells and regulating vasoactive substances in NTG-induced migraine mice. These findings suggest that the FSS formula may be exploited as new phytotherapy for treating migraine.

Unraveling the serotonin saga: from discovery to weight regulation and beyond - a comprehensive scientific review

The prevalence of obesity is rapidly increasing worldwide, while the development of effective obesity therapies lags behind. Although new therapeutic targets to alleviate obesity are identified every day, and drug efficacy is improving, adverse side effects and increased health risks remain serious issues facing the weight-loss industry. Serotonin, also known as 5-HT, has been extensively studied in relation to appetite reduction and weight loss. As a result, dozens of upstream and downstream neural targets of 5-HT have been identified, revealing a multitude of neural circuits involved in mediating the anorexigenic effect of 5-HT. Despite the rise and fall of several 5-HT therapeutics in recent decades, the future of 5-HT as a therapeutic target for weight-loss therapy looks promising. This review focuses on the history of serotonin, the state of current central serotonin research, previous serotonergic therapies, and the future of serotonin for treating individuals with obesity.

Emerging experimental drugs in clinical trials for migraine: observations and key talking points

INTRODUCTION

There have been significant advances in the treatment of migraine. In response to the clinical success of monoclonal antibodies targeting calcitonin gene-related peptide, there is interest in the clinical trial outcomes of alternative emerging drugs that act on novel targets associated with migraine pathophysiology. As approximately 50% of patients do not respond to CGRP therapies, there is significant value in future drug innovation. Emerging drugs in clinical trials for the treatment of migraine aim to fill this need.

AREAS COVERED

The emerging drugs that will be discussed in this review include zavegepant, lasmiditan, delta opioid receptor agonists, neuronal nitric oxide synthase inhibitors, monoclonal antibodies targeting pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor, dual orexin receptor antagonists, metabotropic glutamate receptor 5 antagonists, and inducers of ketosis.

EXPERT OPINION

When considering the preclinical and clinical research related to the emerging drug classes discussed in this review, most therapies are derived from highly supported targets of migraine pathogenesis. Although the individual drugs discussed in this review may be of dubious clinical value, the importance of the therapeutic targets on which they act cannot be understated. Future research is necessary to appropriately target the pathways elucidated by preclinical studies.

Targeting Nociceptive Neurons and Transient Receptor Potential Channels for the Treatment of Migraine

Migraine is a neurovascular disorder that affects approximately 12% of the global population. While its exact causes are still being studied, researchers believe that nociceptive neurons in the trigeminal ganglia play a key role in the pain signals of migraine. These nociceptive neurons innervate the intracranial meninges and convey pain signals from the meninges to the thalamus. Targeting nociceptive neurons is considered promising due to their accessibility and distinct molecular profile, which includes the expression of several transient receptor potential (TRP) channels. These channels have been linked to various pain conditions, including migraine. This review discusses the role and mechanisms of nociceptive neurons in migraine, the challenges of current anti-migraine drugs, and the evidence for well-studied and emerging TRP channels, particularly TRPC4, as novel targets for migraine prevention and treatment.

The Influence of Sleep Disturbance on Chronic Pain

PURPOSE OF REVIEW

The purpose of this review is to present an overview of common sleep disturbance pathologies and their impact on chronic pain, while examining various factors that are implicit in the relationship between sleep disturbance and chronic pain, including neurobiochemistry, anatomy, and systemic mediators, and reviewing recent and landmark literature.

RECENT FINDINGS

Earlier literature reviews and studies have introduced the bidirectional relationship between sleep disturbance and chronic pain; that is, impaired sleep may worsen chronic pain, and chronic pain causes sleep disturbance. However, more recent reviews and studies seem to show a more associative, rather than causative relationship. There have been recent studies that attempt to determine mechanisms that link sleep disturbance and chronic pain; the results of these studies were more varied, ultimately concluding that there may be a separate, yet-to-be discovered mechanism that shows the causative relationship between sleep disturbance and pain. There are several neurotransmitters that are involved in the mediation of chronic pain and sleep disturbance as separate entities, and some studies have shown that there may be mechanisms that govern both chronic pain and sleep disturbance as a single unit. Other neuroendocrine substances also serve to mediate chronic pain and sleep disturbance. All these substances are found to be associated with various sleep disorders and are also associated with chronic pain symptoms as well. Inflammation plays a role in chronic pain and sleep disturbance, with an increase in inflammatory substances and mediators associated with an increase or worsening in chronic pain symptoms and sleep disorders. The HPA axis plays a role in chronic pain and sleep disorders, influencing pain and sleep pathways through stress response, inflammation, and maintenance of homeostasis. There are several variables that influence both chronic pain and sleep disturbance, and more research into these variables may further our understanding into the complex pathways governing the influence of sleep disturbance on pain, and ultimately to improve treatment for this issue.

Lasmiditan for Patients with Migraine and Contraindications to Triptans: A Post Hoc Analysis

INTRODUCTION

As 5-HT1B receptor agonists, triptans produce vasoconstriction and have cardiovascular contraindications and precautions. Lasmiditan, a selective 5-HT1F receptor agonist, has a low affinity for 5-HT1B receptors, does not cause vasoconstriction, and is free of cardiovascular contraindications and precautions. The objective of this post hoc analysis was to evaluate the efficacy and safety of lasmiditan in patients with and without at least one triptan contraindication.

METHODS

Patient subgroups, with and without triptan contraindications, were analyzed from pooled patient data from four randomized, double-blind, placebo-controlled clinical trials (SAMURAI, SPARTAN, CENTURION, and MONONOFU). Patients experiencing a single migraine attack of moderate or severe intensity were treated with lasmiditan 50 mg (SPARTAN and MONONOFU only), 100 mg, 200 mg, or placebo, and efficacy data were recorded in an electronic diary.

RESULTS

Of 5704 patients, 207 (3.6%) patients had at least one contraindication to triptans. Overall subgroup analysis revealed that the effects of lasmiditan on pain freedom, pain relief, freedom from most bothersome symptom, disability freedom, and Patient Global Impression of Change at 2 h post-dose did not differ in patient groups with and without triptan contraindications. These outcomes generally showed a similar benefit pattern for lasmiditan in both subgroups, with all results being statistically significant in patients without contraindications, and pain relief being statistically significant in patients with contraindications. The safety and tolerability profiles of patients with triptan versus without triptan contraindications were similar, including dizziness in 18.3 to 22.8% and somnolence in 7.9 to 9.9% of patients at the highest dose of lasmiditan.

CONCLUSIONS

In pooled analyses from four trials, patients with and without triptan contraindications did not differ in their patterns of lasmiditan efficacy. Lasmiditan may be a treatment option in patients with contraindications to triptans.

TRIAL REGISTRATION NUMBERS

SAMURAI, NCT:02439320; SPARTAN, NCT:02605174; CENTURION, NCT:03670810; and MONONOFU, NCT:03962738.

Migraine signaling pathways: amino acid metabolites that regulate migraine and predispose migraineurs to headache

Migraine is a common, debilitating disorder for which attacks typically result in a throbbing, pulsating headache. Although much is known about migraine, its complexity renders understanding the complete etiology currently out of reach. However, two important facts are clear, the brain and the metabolism of the migraineur differ from that of the non-migraineur. This review centers on the altered amino acid metabolism in migraineurs and how it helps define the pathology of migraine.

Hypervigilance, Allostatic Load, and Migraine Prevention: Antibodies to CGRP or Receptor

Migraine involves brain hypersensitivity with episodic dysfunction triggered by behavioral or physiological stressors. During an acute migraine attack the trigeminal nerve is activated (peripheral sensitization). This leads to central sensitization with activation of the central pathways including the trigeminal nucleus caudalis, the trigemino-thalamic tract, and the thalamus. In episodic migraine the sensitization process ends with the individual act, but with chronic migraine central sensitization may continue interictally. Increased allostatic load, the consequence of chronic, repeated exposure to stressors, leads to central sensitization, lowering the threshold for future neuronal activation (hypervigilance). Ostensibly innocuous stressors are then sufficient to trigger an attack. Medications that reduce sensitization may help patients who are hypervigilant and help to balance allostatic load. Acute treatments and drugs for migraine prevention have traditionally been used to reduce attack duration and frequency. However, since many patients do not fully respond, an unmet treatment need remains. Calcitonin gene-related peptide (CGRP) is a vasoactive neuropeptide involved in nociception and in the sensitization of peripheral and central neurons of the trigeminovascular system, which is implicated in migraine pathophysiology. Elevated CGRP levels are associated with dysregulated signaling in the trigeminovascular system, leading to maladaptive responses to behavioral or physiological stressors. CGRP may, therefore, play a key role in the underlying pathophysiology of migraine. Increased understanding of the role of CGRP in migraine led to the development of small-molecule antagonists (gepants) and monoclonal antibodies (mAbs) that target either CGRP or the receptor (CGRP-R) to restore homeostasis, reducing the frequency, duration, and severity of attacks. In clinical trials, US Food and Drug Administration-approved anti-CGRP-R/CGRP mAbs were well tolerated and effective as preventive migraine treatments. Here, we explore the role of CGRP in migraine pathophysiology and the use of gepants or mAbs to suppress CGRP-R signaling via inhibition of the CGRP ligand or receptor.

Geographic variation in the use of triptans and opioids for the acute treatment of migraine attacks

OBJECTIVE

To assess the geographic variations in triptan and opioid prescribing patterns for patients with migraine.

BACKGROUND

Numerous guidelines recommend triptans as the standard of care for migraine attacks, yet opioids are still widely used for migraine treatment. Variation in the use of opioids and triptans for the treatment of migraine by geographic location is not well known.

METHODS

Using a US claims database, we conducted a retrospective cohort study of adults diagnosed with migraine between 2016 and 2018. We used a 12-month follow-up period to assess triptan and opioid utilization, stratified by the nine Census Bureau-designated divisions. To examine the geographic factors that affect triptan and opioid use among patients, we conducted two sets of multivariable analyses. First, we analyzed the odds of a patient being a triptan or opioid user in the follow-up period, defined as ≥1 triptan or opioid claim. We then analyzed the medication use rate among triptan or opioid users.

RESULTS

Overall, we had a final study population of 113,921 patients. In the follow-up period, 52.9% (60,247/113,921) [range: 48.0%-56.3%] of patients were triptan users and 41.0% (46,708/113,921) [range: 28.9%-48.4%] of patients were opioid users with significant differences across census divisions (p < 0.001). Triptan users had a mean (SD) of 4.8 (4.7) triptan claims annually with no significant differences across divisions (p = 0.188). Opioid users had a mean (SD) of 5.4 (6.8) opioid claims annually with significant differences across divisions (p < 0.001). The observed variation in opioid use stemmed from the proportion of patients using opioids in each region and not from the number of opioid prescriptions per user.

CONCLUSIONS

There was a significant geographic variation in the use of opioids and to a lesser degree the use of triptans. The widespread use of opioids and the large variation in use other than triptans as the standard of care suggest that improvements could be made in the acute treatment of migraine attacks.

Lasmiditan: Acute Migraine Treatment Without Vasoconstriction. A Review

Objective: To review the efficacy and safety of the newly Food and Drug Administration approved drug lasmiditan, and its place in therapy in the treatment of acute migraine attacks. Data Sources: A literature search of Web of Science, PubMed, and Google Scholar was preformed (September 1999 to May 2021) using the following search terms: acute migraine treatment, triptans, lasmiditan, Reyvow, Rimegepant, Nurtec, Ubrogepant, Ubrelvy, migraine, vasoconstriction, and cardiovascular risk. Product labeling, https://www.clinicaltriasl.gov, and product monographs were also reviewed. Study Selection and Data Extraction: Relevant English-language studies were considered. Data Synthesis: Lasmiditan is the first in its class approved for acute migraine treatment. Lasmiditan exerts its therapeutic effect through agonism at the 5-HT_1F receptor, which has been shown to produce no vasoconstriction in preclinical models. Relevance to Patient Care and Clinical Practice: It is both scientifically and clinically relevant to review lasmiditan and determine the value of an acute migraine drug that does not induce vasoconstriction. Patients with preexisting cardiovascular conditions for which current migraine therapy is contraindicated may benefit from therapeutic use of lasmiditan. However, the potential cardiovascular benefit needs to be weighed against the increased central nervous system risks observed with lasmiditan. Conclusions: Lasmiditan is an oral tablet drug that is used for acute migraine abortive treatment and data suggest that it does not induce vasoconstriction, a common side effect often observed with the current first-line abortive migraine treatment drug class, triptans. This is especially important in acute migraine patients with cardiovascular risk factors in which triptan use is contraindicated.

Non-invasive neuromodulation in the acute treatment of migraine: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

A systematic review and meta-analysis was performed to determine the efficacy of non-invasive neuromodulation modalities for the treatment of acute migraine.

BACKGROUND

Although pharmacological treatments are the gold standard for the management of acute migraine, some patients may require non-pharmacological treatment options. Non-invasive neuromodulation may provide an alternative, and techniques include transcranial magnetic stimulation (TMS), non-invasive vagal nerve stimulation (nVNS), non-painful remote electrical stimulation (NRES), and external trigeminal nerve stimulation (e-TNS).

METHODS

This systematic review and meta-analysis was performed following PRISMA guidelines. We searched PUBMED, EMBASE, ClinicalTrials.gov, Cochrane Center Register of Controlled Trials, and LILACS databases. We included randomized controlled clinical trials studying patients with migraine treated with any form of non-invasive neuromodulation. Primary outcome was pain freedom within 2 h post-treatment. Secondary outcomes were pain relief within 2-h post-treatment and sustained pain freedom and sustained pain relief 48 h post-treatment.

RESULTS

Pooled analysis demonstrated a significant effect of non-invasive neuromodulation on pain-free rates within 2 h (RR, 1.66; 95% CI, 1.35 to 2.05; P < 0.00001) and pain relief rates within 2 h (RR, 1.52; 95% CI, 1.13 to 2.05; P = 0.005) post-treatment. Non-invasive neuromodulation had no significant effect on sustained pain freedom at 48 h (RR, 1.56; 95% CI, 0.68 to 3.59; P = 0.29) or sustained pain relief at 48 h (RR, 1.47; 95% CI, 0.57 to 3.77; P = 0.43) after administration.

CONCLUSION

Neuromodulation has demonstrated some efficacy in acute migraine management and may be considered in the treatment paradigm of acute migraine in patients with contraindications to pharmacological therapies.

The Effect and Safety of 5-HT1F Receptor Agonist Lasmiditan on Migraine: A Systematic Review and Meta-Analysis

BACKGROUND

Migraine has a great impact on public health. Current acute therapies do not satisfy all migraineurs. The novel serotonin 5-HT1F receptor agonist appears more promising for aborting migraine attacks.

OBJECTIVE

To evaluate the clinical efficacy and safety of lasmiditan in treating acute migraine attacks.

METHODS

The literature search was performed in PubMed, Embase, and the Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) which assessed the effect and safety of lasmiditan on migraine. The risk of bias was assessed using the Cochrane Collaboration's risk of bias tool. Results were extracted and pooled as risk ratios (RRs) with a fixed or random-effects model.

RESULTS

Based on the four included RCTs, pooled estimates showed that lasmiditan with the 50 mg, 100 mg, and 200 mg doses was superior to placebo at 2 h after the first dose in terms of pain freedom, absence of migraine-associated symptoms, headache relief, no/mild disability, and global impression of change (very much/much better) (RRs ranged from 1.13 to 1.96), except for nausea-free and vomiting-free. Both lasmiditan 100 mg and 200 mg resulted in significantly fewer patients using rescue medication (100 mg: RR = 0.75, 95% CI (0.61, 0.92), P = 0.007; 200 mg: RR = 0.81, 95% CI (0.66, 0.99), P = 0.04) at 2-24 h postdose, compared with placebo. Safety data showed that the proportion of patients reporting at least one treatment-emergent adverse event (TEAE) and the incidence of most common TEAEs such as dizziness, paresthesia, fatigue, somnolence, and nausea was higher in the lasmiditan groups (50 mg, 100 mg, and 200 mg), compared with placebo. There was no significant difference between lasmiditan and placebo in terms of cardiovascular-related TEAEs (RR = 2.75, 95% CI (0.81, 9.37), P = 0.11). Compared with lasmiditan 100 mg, lasmiditan 200 mg was more effective in pain freedom at 2 h after the first dose (RR = 0.83, 95% CI (0.74, 0.94), P = 0.004) but associated with a higher risk of reporting at least one TEAE (RR = 0.88, 95% CI (0.81, 0.96), P = 0.006).

CONCLUSIONS

Lasmiditan with the 50 mg, 100 mg, and 200 mg doses are effective and safe in acute migraine treatment. Lasmiditan 200 mg is more effective than lasmiditan 100 mg in pain freedom, while lasmiditan 100 mg is better tolerated in the short-term follow-up. Further larger sample-size RCTs are required to verify the applicability and tolerability in the long term.

Progress in the Treatment of Migraine Attacks: From Traditional Approaches to Eptinezumab

Migraine is the second cause of disability and of lost years of healthy life worldwide. Migraine is characterized by recurrent headache attacks and accompanying disabling symptoms lasting 4-48 h. In episodic migraine, attacks occur in less than 15 days per month and in chronic migraine, in more than 15 monthly days. Whilst successful translation of pharmacological discoveries into efficacious therapeutics has been achieved in the preventative therapy of chronic migraine, treatment of acute migraine suffers the lack of effective advancements. An effective treatment affords complete freedom from pain two hours after therapy and provides the absence of the most bothersome symptom (MBS) associated with migraine after 2 h. However, available anti-migraine abortive treatments for acute attacks do not represent an effective and safe treatment for all the populations treated. In particular, the most used specific treatment is represented by triptans that offer 2-h sustained freedom from pain achieved in 18-50% of patients but they are contraindicated in coronary artery disease, stroke and peripheral vascular disease due to the vasoconstriction at the basis of their pharmacologic action. The most novel therapies, i.e., gepants and ditans, are without sufficient post-marketing data for secure use. Here, an attempt is proposed to analyse the rational basis and evidence in favour of investigating the efficacy and safety in acute migraine attacks of eptinezumab, i.e., monoclonal antibody (mAb) directed towards calcitonin gene-related peptide (CGRP) unique for intravenous infusion administration.

Efficacy and Safety of Lasmiditan for Acute Treatment of Migraine in Adults: A Meta-Analysis

Monotherapy with triptans in acute migraine is ineffective in many patients and contraindicated in certain cardiovascular diseases where alternative therapeutic options are necessary to explore. This meta-analysis has evaluated the efficacy and safety of lasmiditan for the treatment of acute migraine in adults. After performing a literature search on MEDLINE/PubMed, Scopus, Cochrane databases, and International Clinical Trial Registry Platform, reviewers assessed eligibility and extracted data from 4 relevant articles. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed in the selection, analysis, and reporting of findings. A random-effects model was used to estimate effect size. Quality assessment was done using the risk of bias assessment tool and meta-regression for probable variables affecting effect size. Subgroup analysis was done depending on the dose of lasmiditan. Lasmiditan use was associated with a significantly higher percentage of patients with pain freedom (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.72-2.39; P < .00001), sustained pain freedom (OR, 1.93; 95%CI, 1.55-2.39; P <.00001), headache response (OR, 2.05; 95%CI, 1.77-2.36; P < .00001), clinical disability level (OR, 1.36; 95%CI, 1.20-1.55; P < .00001), patients' global impression (OR, 1.88; 95%CI, 1.69-2.10; P < .00001), and significantly lower use of rescue medication (OR, 0.49; 95%CI, 0.38-0.63; P < .00001) compared to placebo. Lasmiditan use was also associated with a higher likelihood of adverse effects like dizziness (OR, 6.54; 95%CI, 4.24-10.07; P < .00001), paresthesia (OR, 4.28; 95%CI, 2.97-6.17; P < .00001), and fatigue (OR, 5.67; 95%CI, 3.78-8.52; P < .00001) compared to placebo. Subgroup analysis showed a dose-dependent effect of lasmiditan on pain freedom, sustained pain freedom, patient's global impression, and occurrence of adverse drug reactions. Prediction probability for effect estimate favoring placebo was calculated to be 0.0017%. Lasmiditan has shown a favorable effect in terms of efficacy and safety in the treatment of an acute attack of migraine in comparison to placebo. Further studies are needed to evaluate long-term safety, efficacy, and use in specific subgroups of patients. PROSPERO Registration Number: CRD42020177838.

Genetics, pathophysiology, diagnosis, treatment, management, and prevention of migraine

Migraine is a neurological ailment that is characterized by severe throbbing unilateral headache and associated with nausea, photophobia, phonophobia and vomiting. A full and clear mechanism of the pathogenesis of migraine, though studied extensively, has not been established yet. The current available information indicates an intracranial network activation that culminates in the sensitization of the trigemino-vascular system, release of inflammatory markers, and initiation of meningeal-like inflammatory reaction that is sensed as headache. Genetic factors might play a significant role in deciding an individual's susceptibility to migraine. Twin studies have revealed that a single gene polymorphism can lead to migraine in individuals with a monogenic migraine disorder. In this review, we describe recent advancements in the genetics, pathophysiology, diagnosis, treatment, management, and prevention of migraine. We also discuss the potential roles of genetic and abnormal factors, including some of the metabolic triggering factors that result in migraine attacks. This review will help to accumulate current knowledge about migraine and understanding of its pathophysiology, and provides up-to-date prevention strategies.

Development of Mucoadhesive Buccal Film for Rizatriptan: In Vitro and In Vivo Evaluation

The reduced therapeutic efficacy of rizatriptan in migraine treatment is primarily due to low oral bioavailability and extensive first pass metabolism. The purpose of this investigation was to optimize the thin mucoadhesive buccal film of rizatriptan and assess the practicability of its development as a potential substitute for conventional migraine treatment. Buccal films (FR1-FR10) were fabricated by a conventional solvent casting method utilizing a combination of polymers (Proloc, hydroxypropyl methylcellulose and Eudragit RS 100). Drug-loaded buccal films (F1-F4) were examined for mechanical, mucoadhesive, swelling and release characteristics. In vivo pharmacokinetics parameters of selected buccal film (F1) in rabbits were compared to oral administration. Films F1-F4 displayed optimal physicomechanical properties including mucoadhesive strength, which can prolong the buccal residence time. A biphasic, complete and higher drug release was seen in films F1 and F4, which followed Weibull model kinetics. The optimized film, F1, exhibited significantly higher (p < 0.005) rizatriptan buccal flux (71.94 ± 8.26 µg/cm²/h) with a short lag time. Film features suggested the drug particles were in an amorphous form, compatible with the polymers used and had an appropriate surface morphology suitable for buccal application. Pharmacokinetic data indicated a significantly higher rizatriptan plasma level (p < 0.005) and C_max (p < 0.0001) upon buccal film application as compared to oral solution. The observed AUC_0-12h (994.86 ± 95.79 ng.h/mL) in buccal treatment was two-fold higher (p < 0.0001) than the control, and the relative bioavailability judged was 245%. This investigation demonstrates the prospective of buccal films as a viable and alternative approach for effective rizatriptan delivery.

Cluster Headache: A Review and Update in Treatment

PURPOSE OF REVIEW

The treatment of cluster headache has evolved to include a handheld neuromodulation device and a monoclonal antibody in addition to more traditional agents.

RECENT FINDINGS

Galcanezumab is an approved treatment for episodic cluster headache. The non-invasive vagal nerve stimulator has been shown to be effective as a treatment for episodic cluster headache. Dedicated pituitary imaging may not be necessary with a normal MRI of the brain. Cluster headache is the most common trigeminal-autonomic cephalalgia, characterized by unilateral, frequent, debilitating attacks associated with ipsilateral autonomic symptoms. Attacks have a circadian and, often, seasonal pattern with periods of remission that can last months to years in episodic patients. Though a rare disease, an increasing number of studies have revealed novel targets for treatment. Treatment in cluster headache should focus on early intervention to reduce frequency of attacks and the length of the cycle, which improves outcomes and disability. Acute therapy is used to treat attacks, while bridging and preventive therapies are combined to reduce cycle length. Case 1: A 43-year-old man presents with the chief complaint of severe headaches. Upon general examination, he seems uncomfortable, agitated, and exhausted. He states that he hasn't "slept in over a week because of debilitating headaches." His headaches start around the same time every night: when he lays down to go to sleep. The pain is described as sharp, like a "hot poker" to his left eye. His partner has noticed that his eye droops and turns red when the pain starts. The attacks come on abruptly and prevent him from sleeping. The severe pain lasts 30 to 45 min, but he has mild-to-moderate pain that lingers for the rest of the night. He has seen his primary care physician, an allergist, and an ear, nose, and throat (ENT) specialist before coming to see a neurologist. Similar headaches occurred last year during the month of October as well. On further questioning, he reports that these headache attacks have been occurring almost yearly for the past 7 years. Each year, these headaches come on as the weather is changing and occur on a nightly basis for about 3 to 4 weeks.

Migraine with Brainstem Aura Accompanied by Disorders of Consciousness

Migraine with brainstem aura (MBA) accompanied by disorders of consciousness (DOC) is a rare subtype of migraine. The pathophysiology of MBA with DOC has not been elucidated yet. Some patients have a family history of migraine, and women are more affected than men. The aura symptoms are diverse; however, when MBA is combined with DOC, the clinical manifestations are more complicated. Coma is the most common clinical manifestation. The overall duration of the patient’s DOC is short and can often return to normal within half an hour. Headache often occurs after regaining consciousness and can also occur at the same time as DOC. The most common headache is located at the occipital region. Although DOC is reversible, considering the current small number of cases, we still need to improve our understanding of the disease to avoid misdiagnosis. The MBA patient’s electroencephalogram and cerebral blood flow perfusion may have transient changes and may return to normal in the interictal period or after the DOC. Although triptans have traditionally been contraindicated in MBA under drug instructions, the evidence of basilar artery constriction, as postulated in MBA, is lacking. Lasmiditan is currently the first and only 5-HT 1F receptor agonist approved by the Food and Drug Administration. The calcitonin gene-related peptide receptor antagonists and monoclonal antibody therapies may be the most promising for future consideration. Here, the pathophysiology, clinical manifestations, diagnostic tools, and treatment progress for MBA with DOC are reviewed.

Drug interactions and risks associated with the use of triptans, ditans and monoclonal antibodies in migraine

PURPOSE OF REVIEW

The aim of this study was to review current evidence concerning potential risks and interactions associated with concomitant use of drugs indicated for the abortive treatment of migraine, namely triptans and ditans, and more recently developed drugs used for the preventive treatment. The latter drug class encompasses monoclonal antibodies (mAbs), which target either calcitonin gene-related peptide (CGRP) or its receptor.

RECENT FINDINGS

To date, no pharmacokinetic interactions between these drug classes have been reported. However, patients who suffer from triptan- (or ditan-) induced medication overuse headache or those who are nonresponders to triptans might respond less effectively to mAbs. Caution is warranted when coadministrating these drugs in migraine patients with comorbid cardiovascular disease or with an increased cardiovascular risk profile.

SUMMARY

In this review, the main mechanisms of action of triptans, ditans and mAbs targeting CGRP or its receptor are summarized as well as the current evidence on their individual risks. Studies on risks and interactions in case of concomitant use of triptans, ditans and mAbs in migraine patients are relatively scarce. Therefore, these aspects have been considered from a theoretical and hypothetical point of view by taking both their overlapping target, CGRP, and contraindications into account.

Lasmiditan for the acute treatment of migraine

Migraine is a leading cause of morbidity and disability worldwide. Triptans were the first migraine-specific drug class developed and have proven efficacy in treatment of this neurological disease. They are however contraindicated in patients with cardiovascular disease and possibly others, owning to their vasoconstrictive properties. This review will focus on lasmiditan, which has been called the first 'ditan' and 'neurally acting anti-migraine agent', designed to selectively agonize the serotonin 5-HT_1F receptor subtype, providing anti-migraine effects without concomitant vasoconstriction. To date, lasmiditan has proven safe and effective for the acute treatment of migraine in two Phase II and four Phase III trials. Post hoc analysis revealed that the majority of treatment-emergent adverse events were CNS-related, mild-to-moderate in severity and self-limiting. The US FDA label recommends that patients not drive or operate machinery until at least 8 h after taking each dose of lasmiditan.

Beyond its anti-migraine properties, sumatriptan is an anti-inflammatory agent: A systematic review

Sumatriptan is the first available medication from triptans family that was approved by the U.S. Food and Drug Administration for migraine attacks and cluster headaches in 1991. Most of its action is mediated by selective 5-HT_1B/1D receptor agonism. Recent investigations raised the possibility of repositioning of this drug to other indications beyond migraine, as increasing evidence suggests for an anti-inflammatory property of sumatriptan. We performed a literature search using PubMed, Web of Science, Scopus, and Google Scholar using "inflammation AND sumatriptan" or "inflammation AND 5HT1B/D" as the keywords. Then, articles were screened for their relevance and those directly discussing the correlation between inflammation and sumatriptan or 5HT1B/D were included. Total references reviewed or inclusion/exclusion were 340 retrieved full-text articles (n = 340), then based on critical assessment 66 of them were included in this systematic review. Our literature review indicates that at low doses, sumatriptan can reduce inflammatory markers (e.g., interleukin-1β, tumor necrosis factor-α, and nuclear factor-κB), affects caspases and changes cells lifespan. Additionally, nitric oxide synthase and nitric oxide signaling seem to be regulated by this drug. It also inhibits the release of calcitonin gene-related peptide. Sumatriptan protects against many inflammatory conditions including cardiac and mesenteric ischemia/reperfusion, skin flap, pruritus, peripheral, and central nervous system injuries such as spinal cord injury, testicular torsion-detorsion, oral mucositis, and other experimental models. Considering the safety and potency of low dose sumatriptan compared to corticosteroids and other immunosuppressive medications, it is worth to take advantage of sumatriptan in inflammatory conditions.

Autoinjector device for rapid administration of drugs and antidotes in emergency situations and in mass casualty management

There are several situations such as medical emergencies and incidents involving mass casualties where drugs and antidotes have to be administered immediately along with other first aid at the site of the event. Self-administration by the affected person or by a companion is required as a life-saving measure. Autoinjector devices (AIDs) are useful for the rapid administration of drugs and antidotes and they can also be used by those who have not been medically trained. This makes them very convenient for emergency and mass casualty management. An AID has a drug cartridge with an embedded needle for subcutaneous or intramuscular injection, which is usually painless. The drugs are delivered slowly by the AID across a large area in the muscle, which increases the absorption and the drug effects are equal to that of intravenous administration. A variety of AIDs are available, such as atropine and pralidoxime for nerve agent poisoning, epinephrine for anaphylactic shock and allergy, diazepam for seizures, sumatriptan for migraine, amikacin for antibacterial treatment, buprenorphine for pain relief and monoclonal antibodies for a variety of diseases. This review describes the published peer-reviewed literature identified by online searches of journal databases.

The Roles of Serotonin in Neuropsychiatric Disorders

The serotonergic system extends throughout the central nervous system (CNS) and the gastrointestinal (GI) tract. In the CNS, serotonin (5-HT, 5-hydroxytryptamine) modulates a broad spectrum of functions, including mood, cognition, anxiety, learning, memory, reward processing, and sleep. These processes are mediated through 5-HT binding to 5-HT receptors (5-HTRs), are classified into seven distinct groups. Deficits in the serotonergic system can result in various pathological conditions, particularly depression, schizophrenia, mood disorders, and autism. In this review, we outlined the complexity of serotonergic modulation of physiologic and pathologic processes. Moreover, we provided experimental and clinical evidence of 5-HT's involvement in neuropsychiatric disorders and discussed the molecular mechanisms that underlie these illnesses and contribute to the new therapies.

Novel synthetic treatment options for migraine

Introduction: Migraine is one of the most common neurological disorders. Nowadays, the 5-HT_1B/1D receptor agonists, namely triptans, are considered as the standard of care for migraine acute treatment. However, triptans have limitations in some patients, such as incomplete pain relief, headache recurrence, and cardiovascular contraindications. New 5-HT_1F receptor agonists, namely ditans, and calcitonin gene-related peptide receptor antagonists, namely gepants, have been developed as migraine-specific treatments.Areas covered: This paper reviews the available data from RCTs to assess the clinical efficacy, safety, and tolerability profile of lasmiditan, rimegepant, and ubrogepant for the acute treatment of migraine and atogepant for the prevention of migraine.Expert opinion: Available data suggest that lasmiditan, rimegepant, and ubrogepant might not have a clinical efficacy similar to triptans. Lasmiditan did not cause the typical triptan side effects but was associated with central nervous system side effects, causing temporary driving impairment. On the contrary, the new generation of gepants showed a placebo-like tolerability profile and the absence of a specific pattern of side effects. Future studies on lasmiditan and gepants with respect to established effective comparators are mandatory to support phase III results and to help clinicians to balance the benefit/risk profiles of the various acute and preventive medications.

Cost of fremanezumab, erenumab, galcanezumab and onabotulinumtoxinA associated adverse events, for migraine prophylaxis in Spain

Objective: To compare the cost of adverse events (AEs) associated with preventive treatment of migraine with fremanezumab, versus erenumab, galcanezumab, and onabotulinumtoxinA.Methods: A probabilistic modeling analysis was performed, using second-order Monte Carlo simulations, with 1,000 simulations, in patients with at least 4 days of migraine per month, from the perspective of the National Health System and a time horizon of 12 weeks. The frequency of AEs described in the clinical trials was analyzed with 12 weeks of treatment. Unit costs (€) of management of AEs were obtained from public health prices, expert panels, and published Spanish studies.Results: Fremanezumab would generate average savings of -€469 (95% CI -€303; -€674) versus erenumab, -€268 (95% CI -€171; -€391) versus galcanezumab, -€1,100 (95% CI -€704; -€1,608) or -€1,295 (95% CI -€835; -€1,893) versus onabotulinumtoxinA using real-life or clinical trial data, respectively.Conclusions: The different safety profile of treatment with fremanezumab, compared to erenumab, galcanezumab, and onabotulinumtoxinA, would generate savings in health-care resources in all the scenarios considered.

Profiling lasmiditan as a treatment option for migraine

Introduction: In recent years, research into acute migraine treatment has aimed to develop molecules capable of inhibiting trigeminal pathways, mediated by agonism to 5-HT1F receptors in order to avoid the vasoconstrictive action due to the stimulation of 5-HT 1B/1D receptors. A novel migraine drug class, called 'neurally acting anti-migraine agents', has been developed for the management of acute migraine attacks. Lasmiditan is the only compound of this drug class that has been evaluated in Phase III clinical trials.Areas covered: This review discusses lasmiditan including its pharmacokinetics, pharmacodynamics, efficacy and safety profile. Original research and review articles, relative to the period 2010-2019, were included in the reviewed literature.Expert opinion: The most recent phase III trials have demonstrated the efficacy of lasmiditan for acute migraine treatment, even if compared only with placebo. Nevertheless, the low rate of cardiovascular side effects with lasmiditan might offer a potential therapeutic option for migraine patients with cardiovascular disorders. With the lack of data on lasmiditan's pharmacokinetic features, several phase I clinical trials are still ongoing in order to evaluate half-life, metabolism, excretion and the potential production of active metabolites. Possible pharmacodynamic interaction with drugs acting on central nervous system should be evaluated in future studies.

Spiroxatrine derivatives towards 5-HT1A receptor selectivity

BACKGROUND

In our previous work, spiroxatrine was taken as reference compound to develop selective NOP ligands. Therefore, several triazaspirodecanone derivatives were synthesized. Here, we verify their selectivity towards other 5-HT₁ receptor subtypes and with respect to α₂-AR (Adrenergic Receptors).

METHODS

Binding affinities were determined on cells expressing human cloned receptors for 5-HT_1A/B/D and α_2A/B/C subtypes. The Ki values were determined for those with at least 50% radioligand inhibition.

RESULTS

All our derivatives show a moderate affinity for α₂ subtypes, spanning from 5 to 7.5 pK_i values. Moreover, they show affinity values in a μM-nM range at the 5-HT_1A receptor, while they are practically inactive at 5-HT_1B and 5-HT_1D subtypes. Compound 11, the best of the series, has a 5-HT_1A pK_i value of 8.43 similar to spiroxatrine but, notably, it has a 5-HT_1A favorable selectivity ratio of 52, 8 and 29, respectively over α_2A, α_2B and α_2C adrenoceptor subtypes.

CONCLUSIONS

In this SAR study, a 5-HT_1A selective ligand has been identified in which a tetralone moiety replaced the 1,4-benzodioxane of spiroxatrine and the methylene linker to the triazaspirodecanone portion was maintained in position 2.

Pattern of triptans use: a retrospective prescription study in Calabria, Italy

Triptans are 5-hydroxytryptamine 1B/1D receptor agonists used in moderate to severe migraine attacks as first line when non-specific, symptomatic, nonsteroidal anti-inflammatory drugs are not effective. To gain insight in the treatment of migraine in the regional context, this retrospective (from January to August of the years 2017 and 2018) study aimed at monitoring the use of triptans approved by the regional health authority in Calabria. The data demonstrate that the overall treatment of migraine with triptans in the different provinces of Calabria falls in the average regional prescription/dispensation. Interestingly, Crotone showed a trend to an increased amount of defined daily dose/1000 inhabitants per day. The present analysis might stand for homogeneity of treatment of migraineurs in Calabria and highlights the need for better understanding the apparent differences in the local pattern of almotriptan use to improve the appropriateness.

Protein microarray analysis of cytokine expression changes in distal stumps after sciatic nerve transection

A large number of chemokines, cytokines, other trophic factors and the extracellular matrix molecules form a favorable microenvironment for peripheral nerve regeneration. This microenvironment is one of the major factors for regenerative success. Therefore, it is important to investigate the key molecules and regulators affecting nerve regeneration after peripheral nerve injury. However, the identities of specific cytokines at various time points after sciatic nerve injury have not been determined. The study was performed by transecting the sciatic nerve to establish a model of peripheral nerve injury and to analyze, by protein microarray, the expression of different cytokines in the distal nerve after injury. Results showed a large number of cytokines were up-regulated at different time points post injury and several cytokines, e.g., ciliary neurotrophic factor, were downregulated. The construction of a protein-protein interaction network was used to screen how the proteins interacted with differentially expressed cytokines. Kyoto Encyclopedia of Genes and Genomes pathway and Gene ontology analyses indicated that the differentially expressed cytokines were significantly associated with chemokine signaling pathways, Janus kinase/signal transducers and activators of transcription, phosphoinositide 3-kinase/protein kinase B, and notch signaling pathway. The cytokines involved in inflammation, immune response and cell chemotaxis were up-regulated initially and the cytokines involved in neuronal apoptotic processes, cell-cell adhesion, and cell proliferation were up-regulated at 28 days after injury. Western blot analysis showed that the expression and changes of hepatocyte growth factor, glial cell line-derived neurotrophic factor and ciliary neurotrophic factor were consistent with the results of protein microarray analysis. The results provide a comprehensive understanding of changes in cytokine expression and changes in these cytokines and classical signaling pathways and biological functions during Wallerian degeneration, as well as a basis for potential treatments of peripheral nerve injury. The study was approved by the Institutional Animal Care and Use Committee of the Chinese PLA General Hospital, China (approval number: 2016-x9-07) in September 2016.

Cost of chronic and episodic migraine patients in continuous treatment for two years in a tertiary level headache Centre

Background

Migraine is one of the most common neurological diseases and an estimated 1.04 billion people worldwide have been diagnosed with migraine. Available data suggest that migraine is world widely associated with a high economic burden, but there is great variability in estimated costs that depends on the geographical, methodological and temporal differences between the studies. The purpose of this study was to quantify the annual direct cost of episodic migraine (EM) and chronic migraine (CM), both for the patient and for the National Health System (NHS), using data from subjects who attended an Italian tertiary headache centre. Furthermore, we evaluated comparatively the impact of gender and age on the economic burden of migraine.

Methods

We conducted a retrospective and non-interventional observational analysis of the electronic medical records of subjects with EM and CM who consecutively attended the Regional Referral Headache Centre of Rome and undergoing continuous treatment in the 2 years prior to 31 January 2019. This approach was intended to prevent distorsions due to natural fluctuations in migraine status over time. The collected data included demographic characteristics, number of specialist visits, consumption of medications, diagnostic tests, accesses in the emergency department (ED) and days of hospitalization due to the pathology.

Results

Our sample consisted of 548 patients (85.4% women and 14.6% men): 65.5% had CM and 34.5% had EM. The average annual expenditure per patient was €1482. 82.8% of the total cost (€1227) was covered by the NHS. The main item of expenditure were medications that represented 86.8% (€1286), followed by specialist visits (10.2%), hospitalizations for (1.9%), diagnostic tests for (1%) and ED visits for (0.1%). Costs were significantly higher for women than men (€1517 vs. €1274, p = 0.013) and increased with age (p = 0.002). The annual direct cost of CM was 4.8-fold higher than that of EM (€2037 vs. €427, p = 0.001).

Conclusion

Our results provide a valuable estimate of the annual direct cost of CM and EM patients in the specific setting of a tertiary headache centre and confirm the high economic impact of migraine on both the NHS and patients.

The Role of Descending Pain Modulation in Chronic Primary Pain: Potential Application of Drugs Targeting Serotonergic System

Chronic primary pain (CPP) is a group of diseases with long-term pain and functional disorders but without structural or specific tissue pathologies. CPP is becoming a serious health problem in clinical practice due to the unknown cause of intractable pain and high cost of health care yet has not been satisfactorily addressed. During the past decades, a significant role for the descending pain modulation and alterations due to specific diseases of CPP has been emphasized. It has been widely established that central sensitization and alterations in neuroplasticity induced by the enhancement of descending pain facilitation and/or the impairment of descending pain inhibition can explain many chronic pain states including CPP. The descending serotonergic neurons in the raphe nuclei target receptors along the descending pain circuits and exert either pro- or antinociceptive effects in different pain conditions. In this review, we summarize the possible underlying descending pain regulation mechanisms in CPP and the role of serotonin, thus providing evidence for potential application of analgesic medications based on the serotonergic system in CPP patients.

Interim results of a prospective, randomized, open-label, Phase 3 study of the long-term safety and efficacy of lasmiditan for acute treatment of migraine (the GLADIATOR study)

OBJECTIVES

To address the need for long-term lasmiditan data, the GLADIATOR study evaluated the safety (primary) and efficacy (secondary) of lasmiditan for the intermittent, acute treatment of migraine attacks for up to 1 year.

METHODS

In this prospective, randomized, open-label, Phase 3 study, patients who had completed either of two single-attack studies were offered the opportunity to be randomized 1:1 to lasmiditan 100 mg or 200 mg. Patients were asked to use lasmiditan as the first treatment for each new migraine attack of at least moderate severity. Assessments occurred at baseline and at prespecified time increments up to 48 hours after each dose of study drug using an electronic diary, and safety was assessed throughout the study. Migraine Disability Assessment (MIDAS) was assessed at each visit.

RESULTS

As of the cut-off date for this interim analysis (6 March 2018), 1978 patients had received ≥ 1 lasmiditan dose and treated 19,058 migraine attacks. Overall, treatment-emergent adverse events (TEAEs) were similar to those in the single-attack studies and included dizziness (18.6%), somnolence (8.5%), and paresthesia (6.8%). The frequency of TEAEs generally decreased with subsequent attacks. No treatment-related serious adverse events and no cardiovascular TEAEs potentially due to vasoconstriction were observed. For both lasmiditan doses, efficacy measures were generally consistent over study quarters and treated attacks. Overall, across all treated attacks at 2 hours post-dose, pain freedom was observed in 26.9% of the attacks treated with lasmiditan 100 mg and 32.4% of the attacks treated with lasmiditan 200 mg. MIDAS total scores decreased over time.

CONCLUSIONS

The interim results of this long-term study showed intermittent lasmiditan (100 mg and 200 mg) to be generally well tolerated and efficacious for the acute treatment of migraine over a 1-year period. Trial registration number: NCT02565186; https://clinicaltrials.gov/ct2/show/NCT02565186.

Contribution of Corticotropin-Releasing Factor Receptor 1 (CRF1) to Serotonin Receptor 5-HT2CR Function in Amygdala Neurons in a Neuropathic Pain Model

The amygdala plays a key role in emotional-affective aspects of pain and in pain modulation. The central nucleus (CeA) serves major amygdala output functions related to emotional-affective behaviors and pain modulation. Our previous studies implicated the corticotropin-releasing factor (CRF) system in amygdala plasticity and pain behaviors in an arthritis model. We also showed that serotonin (5-HT) receptor subtype 5-HT2CR in the basolateral amygdala (BLA) contributes to increased CeA output and neuropathic pain-like behaviors. Here, we tested the novel hypothesis that 5-HT2CR in the BLA drives CRF1 receptor activation to increase CeA neuronal activity in neuropathic pain. Extracellular single-unit recordings of CeA neurons in anesthetized adult male rats detected increased activity in neuropathic rats (spinal nerve ligation model) compared to sham controls. Increased CeA activity was blocked by local knockdown or pharmacological blockade of 5-HT2CR in the BLA, using stereotaxic administration of 5-HT2CR short hairpin RNA (shRNA) viral vector or a 5-HT2CR antagonist (SB242084), respectively. Stereotaxic administration of a CRF1 receptor antagonist (NBI27914) into the BLA also decreased CeA activity in neuropathic rats and blocked the facilitatory effects of a 5-HT2CR agonist (WAY161503) administered stereotaxically into the BLA. Conversely, local (BLA) knockdown of 5-HT2CR eliminated the inhibitory effect of NBI27914 and the facilitatory effect of WAY161503 in neuropathic rats. The data suggest that 5-HT2CR activation in the BLA contributes to neuropathic pain-related amygdala (CeA) activity by engaging CRF1 receptor signaling.

A Chinese Prescription Chuanxiong Chatiao San for Migraine: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Backgrounds

Chuanxiong Chatiao san (CXCT) is a famous Chinese classical prescription. It has a favorable effect in treating migraine. It is reported that CXCT combined with Western conventional medicine (WCM) could increase the therapeutic efficacy on migraine. The purpose of this paper is to systematically assess the clinical efficacy, safety, and some indexes of CXCT for migraine.

Methods

PubMed, Embase Database, China National Knowledge Infrastructure (CNKI), Wanfang Database, the Cochrane Library, and the CBM were searched from January 2000 to February 2019. We made a detailed record of outcome measurements. Meta-analysis was performed using RevMan 5.3 software.

Results

A total of 3307 patients were included in the 37 articles. Meta-analysis showed that CXCT significantly increased the total efficiency rate (TER), compared with Western medicine treatment (WMC) (P < 0.00001). When CXCT is combined with WMC, the result showed that P < 0.00001. CXCT was significantly reduced the adverse events (AEs) compared with WMC (P < 0.00001). The levels of VAS, number of migraine episodes (NE), and time of headache duration (TD) were significantly reduced (P < 0.00001). Platelet function and blood rheology level were improved via a significantly decrease in 5-HT and β-EP (P < 0.00001). Other indicators such as substance P, CGRP high-cut viscosity, low-cut viscosity, plasma viscosity, and fibrinogen were significantly reduced (P < 0.00001).

Conclusion

Our findings provide evidence that CXCT and CXCT combined with WMC have higher efficacy in the treatment of migraine compared with WCM alone. Methodological quality was generally low, so the conclusion of this paper has some limitations and it has to be carefully evaluated.

Liposomal Curcumin Enhances the Effect of Naproxen in a Rat Model of Migraine

BACKGROUND Curcumin is an antioxidant that reduces inflammation and pain. This study aimed to assess the effect of pretreatment with naproxen and liposomal curcumin compared with naproxen and curcumin solution on oxidative stress parameters and pain in a rat model of migraine. MATERIAL AND METHODS Sixty-three male Wistar rats included a control group (n=9) and a rat model of migraine (n=54) induced by intraperitoneal injection of nitroglycerin (1 mg/0.1 kg). The rat model group was divided into an untreated control group (n=9), a group pretreated with naproxen alone (2.8 mg/kg) (n=9), a group pretreated with naproxen (2.8 mg/kg) combined with curcumin solution (1 mg/0.1 kg) (n=9), a group pretreated with naproxen (2.8 mg/kg) combined with curcumin solution (2 mg/0.1 kg) (n=9), a group pretreated with naproxen (2.8 mg/kg) combined with liposomal curcumin solution (1 mg/0.1 kg) (n=9) a group pretreated with naproxen (2.8 mg/kg) combined with liposomal curcumin solution (2 mg/0.1 kg) (n=9). Spectroscopy measured biomarkers of total oxidative status and nociception was tested using an injection of 1% of formalin into the rat paw. RESULTS Expression of biomarkers of oxidative stress and enhanced nociception were significantly increased following pretreatment with combined naproxen and liposomal curcumin compared with curcumin solution or naproxen alone (P<0.001). Combined curcumin solution and naproxen were more effective at a concentration of 2 mg/0.1kg for the first nociceptive phase (P<0.005). CONCLUSIONS In a rat model of migraine, combined therapy with liposomal curcumin and naproxen showed an improved antioxidant effect and anti-nociceptive effect.