Is selective 5-HT1F receptor agonism an entity apart from that of the triptans in antimigraine therapy?

5-HT1B receptor activation produces rapid antidepressant-like effects in rodents

Ketamine is noted for its rapid onset antidepressant response and effectiveness in patients with treatment resistant depression. While most research has focused on glutamatergic mechanisms, recent studies show that antidepressant-like effects in rodents are dependent upon the serotonergic (5-HT) system and suggest a potential contribution of the 5-HT1B receptor. In this study we utilized CP-94253 to examine whether 5-HT1B receptor agonism produces rapid and sustained antidepressant-like effects, focusing on rodent models and treatment approaches commonly used to demonstrate the differentiated response to ketamine. We first confirmed that CP-94253 is a potent 5-HT1B agonist in vitro and that CP-94253 occupies brain 5-HT1B receptors at the doses tested. CP-94253 reduced immobility in the mouse forced swim test (FST) and exhibited a prominent antidepressant signature in the mouse-behavior phenotyping platform SmartCube®. When examined 24 h after acute treatment, CP-94253 reduced FST immobility in both naïve rats and in rats receiving chronic interferon alpha treatment. Ex vivo hippocampal long-term potentiation was also enhanced in naïve rats receiving acute CP-94253 treatment, 24 h prior to the recordings. In mice exposed to chronic social defeat stress, antidepressant-like effects in the tail suspension and sucrose preference tests were seen 1 h and 24 h after acute treatment, respectively. Finally, whole brain c-fos imaging in mice showed that CP-94253 modulates neuronal activity in discrete brain regions including the lateral habenula circuit implicated in depression and the ketamine treatment response. Collectively these results support the further investigation of 5-HT1B agonism as a novel treatment approach for major depressive disorder.

The influence of pharmacodynamics and pharmacokinetics on the antimigraine efficacy and safety of novel anti-CGRPergic pharmacotherapies: a narrative review

INTRODUCTION

Migraine is a complex disorder, and its etiology is not yet fully understood. In the last 40 years, calcitonin gene-related peptide (CGRP) has been central to the understanding of migraine pathophysiology, leading to the development of new molecules targeting the CGRPergic system. These new molecules, such as gepants and monoclonal antibodies, are effective, well-tolerated, and safe, and are approved for clinical use.

AREAS COVERED

By searching multiple electronic scientific databases, this narrative review examined: (i) the role of CGRP in migraine; and (ii) the current knowledge on the effects of CGRPergic antimigraine pharmacotherapies, including a brief analysis of their pharmacodynamic and pharmacokinetic characteristics.

EXPERT OPINION

Current anti-CGRPergic medications, although effective, have limitations, such as side effects and lack of antimigraine efficacy in some patients. The existence of patients with medication-resistant migraine may be due to the: (i) complex migraine pathophysiology, in which several systems appear to be deregulated before, during, and after a migraine attack; and (ii) pharmacodynamic and pharmacokinetic properties of antimigraine medications. As envisioned here, although seminal studies support the notion that CGRP plays a key role in migraine headache, the dysfunction of CGRPergic transmission does not seem to be relevant in all cases.

Recent Development of Zolmitriptan Formulation in Migraine Therapy: Production, Metabolism and Pharmaceutical Aspects

The triptans class of pharmaceuticals, which was created to treat acute migraine, is made up of indole-containing drugs that bind to a subset (1B/1D) of 5-hydroxytryptamine receptors and are agonists of serotonin receptors. At the moment, naratriptan, eletriptan, zolmitriptan, rizatriptan, almotriptan, and frovatriptan are the seven types of triptans available on the market. Among these are the FDA-approved triptans, Zolmitriptan and Sumatriptan, which are selective serotonin (5-hydroxytryptamine) agonists. Zolmitriptan, a synthetic tryptamine derivative and a well-known member of the triptan family, is available as an orally disintegrating tablet, nasal spray, and tablet. There are melt formulations of rizatriptan and zolmitriptan available on the market that are easier to use and absorb, comparable to regular pills. Recently, the FDA approved zolmitriptan, a medication with tolerability comparable to sumatriptan. Whereas zolmitriptan is only available as an oral melt or tablet, sumatriptan is available as a nasal spray, oral preparation, or self-injectable kit. The only known antimigraine drugs that were widely utilized before the triptan period were ergotamine and dihydroergotamine. However, zolmitriptan binds to plasma proteins only 25% of the time because of significant first-pass degradation. Researchers have looked into fresh ideas for solving this issue and innovations to overcome its pharmacokinetic difficulties. This article emphasizes the role of zolmitriptan in the treatment of migraines, highlighting its pharmacological properties, production, metabolism, and structural features.

Hallmarks of primary headache: part 1 - migraine

BACKGROUND AND AIM

Migraine is a common disabling conditions which, globally, affects 15.2% of the population. It is the second cause of health loss in terms of years lived with disability, the first among women. Despite being so common, it is poorly recognised and too often undertreated. Specialty centres and neurologists with specific expertise on headache disorders have the knowledge to provide specific care: however, those who do not regularly treat patients with migraine will benefit from a synopsis on the most relevant and updated information about this condition. This paper presents a comprehensive view on the hallmarks of migraine, from genetics and diagnostic markers, up to treatments and societal impact, and reports the elements that identify migraine specific features.

MAIN RESULTS

The most relevant hallmark of migraine is that it has common and individual features together. Besides the known clinical manifestations, migraine presentation is heterogeneous with regard to frequency of attacks, presence of aura, response to therapy, associated comorbidities or other symptoms, which likely reflect migraine heterogeneous genetic and molecular basis. The amount of therapies for acute and for prophylactic treatment is really wide, and one of the difficulties is with finding the best treatment for the single patient. In addition to this, patients carry out different daily life activities, and might show lifestyle habits which are not entirely adequate to manage migraine day by day. Education will be more and more important as a strategy of brain health promotion, because this will enable reducing the amount of subjects needing specialty care, thus leaving it to those who require it in reason of refractory condition or presence of comorbidities.

CONCLUSIONS

Recognizing the hallmarks of migraine and the features of single patients enables prescribing specific pharmacological and non-pharmacological treatments. Medical research on headaches today particularly suffers from the syndrome of single-disease approach, but it is important to have a cross-sectional and joint vision with other close specialties, in order to treat our patients with a comprehensive approach that a heterogeneous condition like migraine requires.

The putative proton-coupled organic cation antiporter is involved in uptake of triptans into human brain capillary endothelial cells

BACKGROUND

Triptans are anti-migraine drugs with a potential central site of action. However, it is not known to what extent triptans cross the blood-brain barrier (BBB). The aim of this study was therefore to determine if triptans pass the brain capillary endothelium and investigate the possible underlying mechanisms with focus on the involvement of the putative proton-coupled organic cation (H+/OC) antiporter. Additionally, we evaluated whether triptans interacted with the efflux transporter, P-glycoprotein (P-gp).

METHODS

We investigated the cellular uptake characteristics of the prototypical H+/OC antiporter substrates, pyrilamine and oxycodone, and seven different triptans in the human brain microvascular endothelial cell line, hCMEC/D3. Triptan interactions with P-gp were studied using the IPEC-J2 MDR1 cell line. Lastly, in vivo neuropharmacokinetic assessment of the unbound brain-to-plasma disposition of eletriptan was conducted in wild type and mdr1a/1b knockout mice.

RESULTS

We demonstrated that most triptans were able to inhibit uptake of the H+/OC antiporter substrate, pyrilamine, with eletriptan emerging as the strongest inhibitor. Eletriptan, almotriptan, and sumatriptan exhibited a pH-dependent uptake into hCMEC/D3 cells. Eletriptan demonstrated saturable uptake kinetics with an apparent Km of 89 ± 38 µM and a Jmax of 2.2 ± 0.7 nmol·min-1·mg protein-1 (n = 3). Bidirectional transport experiments across IPEC-J2 MDR1 monolayers showed that eletriptan is transported by P-gp, thus indicating that eletriptan is both a substrate of the H+/OC antiporter and P-gp. This was further confirmed in vivo, where the unbound brain-to-unbound plasma concentration ratio (Kp,uu) was 0.04 in wild type mice while the ratio rose to 1.32 in mdr1a/1b knockout mice.

CONCLUSIONS

We have demonstrated that the triptan family of compounds possesses affinity for the H+/OC antiporter proposing that the putative H+/OC antiporter plays a role in the BBB transport of triptans, particularly eletriptan. Our in vivo studies indicate that eletriptan is subjected to simultaneous brain uptake and efflux, possibly facilitated by the putative H+/OC antiporter and P-gp, respectively. Our findings offer novel insights into the potential central site of action involved in migraine treatment with triptans and highlight the significance of potential transporter related drug-drug interactions.

Therapeutic Options for Migraines in the Microsurgical Patient: A Scoping Review

BACKGROUND

There exists an increasing array of treatments proposed to prevent, alleviate, and abort symptoms of a migraine; however, for patients who undergo reconstructive microsurgery, caution must be taken to preserve vascular integrity. This study is the first-to-date scoping review of vascular and bleeding risk of current migraine therapies, with the purpose of identifying potential therapeutic agents for postoperative migraine management appropriate for microsurgical patients.

METHODS

Currently available migraine therapeutics were compiled from the UpToDate software system and the American Academy of Family Physicians. A PubMed literature review was performed for each therapeutic's effect on bleeding or vascular involvement. Data were compiled into tables of abortive, symptom-controlling and prophylactic, and nonpharmacologic treatments. Expert microsurgeons reviewed the data to provide recommendations for optimized patient care.

RESULTS

Triptans and other ergot derivatives demonstrated strong evidence of vasoconstriction and were greatly advised against for immediate postmicrosurgical use. Novel pharmaceutical therapies such as lasmiditan and calcitonin gene-related peptide antagonists have no literature indicating potential for vasoconstriction or hematoma and remain an investigational option for abortive medical treatment. For symptom control, acetaminophen appears the safest option, with clinical judgment and further research needed for use of nonsteroidal antiinflammatory drugs. Alternative treatment techniques may include migraine prophylaxis with botulinum toxin injection or nutraceutical treatment by means of magnesium supplementation or coenzyme Q10 administration, minimizing the need for additional medication in the postoperative setting.

CONCLUSIONS

Patients undergoing reconstructive microsurgery have a unique medical profile limiting the therapeutic options available to treat migraines. This review provides preliminary evidence to be considered as a guide for prescribing therapeutics for migraine in the postoperative setting.

Exploration of Lasmiditan 200 mg Versus 100 mg for the Treatment of Migraine: A Meta-analysis Based on Aggregate Data

OBJECTIVES

Lasmiditan holds important potential in treating migraine, but its ideal dose remains elusive. This meta-analysis is conducted based on aggregate data and aims to compare the efficacy of lasmiditan 200 mg versus 100 mg for acute treatment of migraine attack.

METHODS

PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases were systematically searched, and we included the randomized controlled trials comparing the efficacy of lasmiditan 200 mg versus 100 mg for migraine patients. This meta-analysis was conducted using the random-effect model or fixed-effect model based on the heterogeneity. The primary outcome was pain free at 2 hours. Secondary outcomes included pain relief at 2 hours, pain free at 24 hours, most bothersome symptom free at 2 hours, and adverse events.

RESULTS

Seven randomized controlled trials and 6515 patients were included in this meta-analysis. Compared with lasmiditan 100 mg for migraine patients, lasmiditan 200 mg was able to significantly improve pain free at 2 hours (odd ratio [OR], 1.28; 95% confidence interval [CI], 1.14-1.44; P < 0.0001) and pain free at 24 hours (OR, 1.35; 95% CI, 1.14-1.60; P = 0.0005), but showed no effect on pain relief at 2 hours (OR, 1.00; 95% CI, 0.90-1.12; P = 0.98) or most bothersome symptom free at 2 hours (OR, 0.93; 95% CI, 0.83-1.03; P = 0.17). Lasmiditan 200 mg was associated with the increase in adverse events compared with lasmiditan 100 mg (OR, 1.28; 95% CI, 1.15-1.43; P < 0.0001).

CONCLUSIONS

Lasmiditan 200 mg is more effective to improve pain free at 2 hours and 24 hours than lasmiditan 100 mg for the acute treatment of migraine patients.

Risk of Stroke and Myocardial Infarction Among Initiators of Triptans

Importance

Triptans are contraindicated in patients with ischemic heart disease or previous myocardial infarction, and caution is advised when prescribing these drugs to patients with vascular risk factors. However, controlled observational studies have either shown no association or an apparent lower risk, possibly owing to a channeling of triptans to individuals at low risk of cardiovascular outcomes, and it remains unclear whether avoiding triptan treatment for these patients is meaningful.

Objective

To establish whether an association between triptans and ischemic events could be demonstrated using a self-controlled design because this type of design is robust to the previously mentioned type of confounding.

Design, Setting, and Participants

All people in nationwide Danish registries who were initiating triptans and all the ischemic events that they experienced were identified. A case-crossover design was used to estimate odds ratios (OR) for associations between first-ever triptan use and ischemic outcomes, comparing triptan exposure in the 2-week period up to the event with four 2-week reference periods. Data were obtained for the period January 1995 to August 2022. Included from the population of Denmark were individuals redeeming a prescription for any triptan and experiencing at least 1 of 3 predefined ischemic outcomes. No one was excluded.

Exposure

Initiation of any triptan.

Main Outcomes and Measures

Acute myocardial infarction, ischemic stroke, or nonspecified stroke.

Results

Identified were a total of 429 612 individuals (median [IQR] age, 38 [28-48] years; 325 687 female [75.8%]) who redeemed a first prescription for a triptan in the study period. Of these patients, 11 (0.003%) had a myocardial infarction with the first triptan prescription in either a focal or referent window (odds ratio [OR], 3.3; 95% CI, 1.0-10.9), 18 (0.004%) had ischemic stroke (OR, 3.2; 95% CI, 1.3-8.1), and 35 (0.008%) had ischemic/nonspecified stroke (OR, 3.0; 95% CI, 1.5-5.9). Case patients had a median age of approximately 60 years and had a high-risk cardiovascular profile.

Conclusions and Relevance

Results of this case-crossover study suggest that triptan initiation was associated with higher risk of ischemic stroke and myocardial infarction. For the individual patient with low background cardiovascular risk, the risk of an ischemic event after triptan initiation was very low.

Comparison of Lasmiditan 200 mg Versus 100 mg for Migraine Patients: A Meta-analysis of Randomized Controlled Studies

INTRODUCTION

The ideal dose of lasmiditan for migraine is not clear. This meta-analysis aims to compare the efficacy of lasmiditan 200 mg versus 100 mg for migraine patients.

METHODS

We have searched several databases including PubMed, Embase, Web of Science, EBSCO, and Cochrane Library Databases and selected the randomized controlled trials comparing the efficacy of lasmiditan 200 mg versus 100 mg for migraine patients. This meta-analysis was conducted using the random-effect model.

RESULTS

Five randomized controlled trials were included in this meta-analysis. Compared with lasmiditan 100-mg group in migraine patients, lasmiditan 200-mg group was associated with substantially increased pain free at 2 hours (odds ratio [OR], 1.27; 95% confidence interval [CI], 1.12-1.44; P = 0.0002) and pain free at 24 hours (OR, 1.31; 95% CI, 1.08-1.60; P = 0.007) but demonstrated no obvious impact on pain relief at 2 hours (OR, 1.02; 95% CI, 0.91-1.16; P = 0.72) or MBS free at 2 hours (OR, 0.94; 95% CI, 0.77-1.14; P = 0.52). In addition, the incidence of adverse events was higher in lasmiditan 200-mg group than that in lasmiditan 100-mg group (OR, 1.29; 95% CI, 1.15-1.45; P < 0.0001).

CONCLUSIONS

Lasmiditan 200 mg is better for the treatment of migraine patients than lasmiditan 100 mg.

Health equity, care access and quality in headache - part 2

BACKGROUND

Headache disorders are a global public health concern affecting diverse populations. This review examines headache service organizations in low-, middle-, and high-income countries. It addresses global challenges in pharmacological headache treatment, with a focus on safety, tolerability, reproductive and child health, and outlines disparities in accessing innovative treatments worldwide.

MAIN BODY

Organized headache services are essential due to the wide prevalence and varying severity of headache disorders. The tiered headache service model is globally recognized, although its implementation varies based on financial and workforce considerations. Headache burden affects well-being, causing disability, economic challenges, and work limitations, irrespective of location or income. All nations still require improved diagnosis and treatment, and the majority of countries face obstacles including limited access, awareness, economic barriers, and inadequate health policies. Provided adequate internet availability, telemedicine could help improve health equity by expanding access to headache care, since it can offer patients access to services without lengthy waiting times or extensive travel and can provide healthcare unavailable in underserved areas due to staff shortages. Numerous health disparities restrict global access to many headache medications, especially impacting individuals historically excluded from randomized controlled trials, such as those with cardiovascular and cerebrovascular conditions, as well as pregnant women. Furthermore, despite advancements in researching migraine treatments for young patients, the options for treatment remain limited. Access to headache treatment relies on factors like medication availability, approval, financial coverage, and healthcare provider expertise. Inadequate public awareness leads to neglect by policymakers and undertreatment by patients and healthcare providers. Global access discrepancies are exacerbated by the introduction of novel disease-specific medications, particularly impacting Asian, African, and Latin American nations excluded from clinical trials. While North America and Europe experience broad availability of migraine treatments, the majority of countries worldwide lack access to these therapies.

CONCLUSIONS

Healthcare disparities, treatment access, and medication availability are concerning issues in headache medicine. Variations in national healthcare systems impact headache management, and costly innovative drugs are widening these gaps. Healthcare practitioners and experts should acknowledge these challenges and work towards minimizing access barriers for equitable global headache care in the future.

A Case of Reversible Posterior Leukoencephalopathy Syndrome (PRES) With a History of Migraine and Onset With Initial Visual Aura and Migraine-Like Headache, With a Significant Response to Lasmiditan: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a neurological disease that presents with various neurological symptoms and is often accompanied by elevated blood pressure at onset. Neuroimaging, especially magnetic resonance imaging (MRI), often shows a characteristic parieto-occipital pattern with a symmetrical distribution of changes, reflecting vasogenic edema. Hypertension and endothelial cell damage are the most common causes of PRES. An association between migraine and endothelial cell damage has been suggested, but the relationship between migraine and PRES is unknown. Reports on PRES triggered by migraines are scarce. We report a case of PRES in a 59-year-old woman with migraine without aura. At the onset, the patient experienced a first-ever visual aura and a migraine-like headache. In this case, it was also difficult to distinguish between PRES headache and headache caused by a pre-existing migraine; however, lasmiditan, an acute migraine treatment without vasoconstrictive properties, was remarkably effective for headaches.

Towards precision medicine in migraine: Recent therapeutic advances and potential biomarkers to understand heterogeneity and treatment response

After 35 years since the introduction of the International Classification of Headache Disorders (ICHD), we are living in the era of the second great revolution in migraine therapies. First, discoveries of triptans provided a breakthrough in acute migraine treatment utilizing bench-to-bedside research results on the role of serotonin in migraine. Next, the discovery of the role of neuropeptides, more specifically calcitonin gene-related peptide (CGRP) in migraine attack led to the development of anti-CGRP therapies that are effective both in acute and preventive treatment, and are also able to reduce migraine-related burden. Here, we reviewed the most recent clinical studies and real-world data on available migraine-specific medications, including triptans, ditants, gepants and anti-CGRP monoclonal antibodies. Novel drug targets, such as PACAP and amylins were also discussed. To address the main challenges of migraine therapy, the high heterogeneity of people with migraine, the prevalent presence of various comorbid disorders, and the insufficient medical care of migraine patients were covered. Promising novel approaches from the fields of omics, blood and saliva biomarker, imaging and provocation studies might bring solutions for these challenges with the potential to identify further drug targets, distinguish more homogeneous patient subgroups, contribute to more optimal drug selection strategies, and detect biomarkers in association with headache features or predicting treatment efficacy. In the future, the combined analysis of data of different biomarker modalities with machine learning algorithms may serve precision medicine in migraine treatment.

Mode and site of action of therapies targeting CGRP signaling

Targeting CGRP has proved to be efficacious, tolerable, and safe to treat migraine; however, many patients with migraine do not benefit from drugs that antagonize the CGRPergic system. Therefore, this review focuses on summarizing the general pharmacology of the different types of treatments currently available, which target directly or indirectly the CGRP receptor or its ligand. Moreover, the latest evidence regarding the selectivity and site of action of CGRP small molecule antagonists (gepants) and monoclonal antibodies is critically discussed. Finally, the reasons behind non-responders to anti-CGRP drugs and rationale for combining and/or switching between these therapies are addressed.

The Neuropsychiatric Safety Profile of Lasmiditan: A Comparative Disproportionality Analysis with Triptans

Migraine constitutes the world's second-leading cause of disability. Triptans, as serotonin 5-HT1B/1D receptor agonists, remain the first-line treatment, despite discouraged use in individuals at high cardiovascular risk. Lasmiditan, a selective lipophilic 5-HT1F agonist without vasoconstrictive effects, is an emerging option. We aimed to investigate the safety profile of lasmiditan in the WHO pharmacovigilance database (VigiBase®) using a comparative disproportionality analysis with triptans. VigiBase® was queried for all reports involving lasmiditan and triptans. Disproportionality analyses relied on the calculation of the information component (IC), for which 95% confidence interval (CI) lower bound positivity was required for signal detection. We obtained 826 reports involving lasmiditan. Overall, 10 adverse drug reaction classes were disproportionately reported with triptans, while only neurological (IC 1.6; 95% CI 1.5-1.7) and psychiatric (IC 1.5; 95% CI 1.3-1.7) disorders were disproportionately reported with lasmiditan. Sedation, serotonin syndrome, euphoric mood, and autoscopy had the strongest signals. When compared with triptans, 19 out of 22 neuropsychiatric signals persisted. The results of our analysis provide a more precise semiology of the neuropsychiatric effects of lasmiditan, with symptoms such as autoscopy and panic attacks. The cardiovascular adverse drug reaction risk with triptans was confirmed. In contrast, caution is warranted with lasmiditan use in patients with neurological or psychiatric comorbidities or serotonin syndrome risk. Our study was hindered by pharmacovigilance flaws, and further studies should help in validating these results. Our findings suggest that lasmiditan is a safe alternative for migraine treatment, especially when the neuropsychiatric risk is outweighed by the cardiovascular burden.

Serotonergic Modulation of Neurovascular Transmission: A Focus on Prejunctional 5-HT Receptors/Mechanisms

5-Hydroxytryptamine (5-HT), or serotonin, plays a crucial role as a neuromodulator and/or neurotransmitter of several nervous system functions. Its actions are complex, and depend on multiple factors, including the type of effector or receptor activated. Briefly, 5-HT can activate: (i) metabotropic (G-protein-coupled) receptors to promote inhibition (5-HT₁, 5-HT₅) or activation (5-HT₄, 5-HT₆, 5-HT₇) of adenylate cyclase, as well as activation (5-HT₂) of phospholipase C; and (ii) ionotropic receptor (5-HT₃), a ligand-gated Na⁺/K⁺ channel. Regarding blood pressure regulation (and beyond the intricacy of central 5-HT effects), this monoamine also exerts direct postjunctional (on vascular smooth muscle and endothelium) or indirect prejunctional (on autonomic and sensory perivascular nerves) effects. At the prejunctional level, 5-HT can facilitate or preclude the release of autonomic (e.g., noradrenaline and acetylcholine) or sensory (e.g., calcitonin gene-related peptide) neurotransmitters facilitating hypertensive or hypotensive effects. Hence, we cannot formulate a specific impact of 5-HT on blood pressure level, since an increase or decrease in neurotransmitter release would be favoured, depending on the type of prejunctional receptor involved. This review summarizes and discusses the current knowledge on the prejunctional mechanisms involved in blood pressure regulation by 5-HT and its impact on some vascular-related diseases.

Prolactin and oxytocin: potential targets for migraine treatment

Migraine is a severe neurovascular disorder of which the pathophysiology is not yet fully understood. Besides the role of inflammatory mediators that interact with the trigeminovascular system, cyclic fluctuations in sex steroid hormones are involved in the sex dimorphism of migraine attacks. In addition, the pituitary-derived hormone prolactin and the hypothalamic neuropeptide oxytocin have been reported to play a modulating role in migraine and contribute to its sex-dependent differences. The current narrative review explores the relationship between these two hormones and the pathophysiology of migraine. We describe the physiological role of prolactin and oxytocin, its relationship to migraine and pain, and potential therapies targeting these hormones or their receptors.In summary, oxytocin and prolactin are involved in nociception in opposite ways. Both operate at peripheral and central levels, however, prolactin has a pronociceptive effect, while oxytocin appears to have an antinociceptive effect. Therefore, migraine treatment targeting prolactin should aim to block its effects using prolactin receptor antagonists or monoclonal antibodies specifically acting at migraine-pain related structures. This action should be local in order to avoid a decrease in prolactin levels throughout the body and associated adverse effects. In contrast, treatment targeting oxytocin should enhance its signalling and antinociceptive effects, for example using intranasal administration of oxytocin, or possibly other oxytocin receptor agonists. Interestingly, the prolactin receptor and oxytocin receptor are co-localized with estrogen receptors as well as calcitonin gene-related peptide and its receptor, providing a positive perspective on the possibilities for an adequate pharmacological treatment of these nociceptive pathways. Nevertheless, many questions remain to be answered. More particularly, there is insufficient data on the role of sex hormones in men and the correct dosing according to sex differences, hormonal changes and comorbidities. The above remains a major challenge for future development.

The role of hippocampal 5-HT1D and 5-HT1F receptors on learning and memory in rats

Serotonin is a neurotransmitter, which is involved in memory via its receptors. The 5-HT_1D and 5-HT_1F receptors mainly exist in the hippocampus, which plays an important role in memory processing. However, few studies have assessed the effect of these serotonin receptors on memory. We evaluated the effect of a 5-HT_1D receptor agonist, PNU142633, 5-HT_1D receptor antagonist, BRL15572 hydrochloride, and 5-HT1F receptor agonist, LY344864, on the recognition and avoidance memory in the hippocampus area. Fifty adult male Wistar rats weighing 200-250 g were divided into the control, sham-operated, PNU, BRL, and LY groups (n=10 per group). Bilateral guide cannulas were implanted into the dentate gyrus area of the hippocampus. The drugs were administered at the dose of 1 μg/μl before the novel object recognition (NOR) and passive avoidance learning (PAL) tests. The results showed that in the NOR test, the administration of PNU and LY had no significant effect on recognition index; however, the recognition index was increased by BRL. In the PAL test, the administration of PNU had no significant effect on recognition index, but the administration of BRL and LY increased the time spent in the dark compartment of the apparatus and decreased the step-through latency into the dark compartment apparatus. It can be concluded that the inhibition of the hippocampal 5-HT_1D receptor improved cognition memory but impaired avoidance memory. Activation of the hippocampal 5-HT_1F receptor had no effect on cognitive memory but impaired avoidance memory.

Place of next generation acute migraine specific treatments among triptans, non-responders and contraindications to triptans and possible combination therapies

Background: For many years triptans have been the cornerstone of acute migraine treatment. Nevertheless, treatment with triptans may not always be initiated due to contraindications (seen in approximately one fifth of patients) or inadequate response (seen in approximately one third of patients). New acute therapies, including 5-hydroxytryptamine (5-HT)_1F receptor agonists, also known as ditans (lasmiditan) and small molecule antagonists of the calcitonin gene-related peptide receptor, also known as gepants (rimegepant and ubrogepant), may be an effective alternative. Methods: We searched Pubmed for keywords, summarized the literature and provided a comprehensive review on the place of next generation acute migraine specific treatments among triptans. Results and conclusion: Post-hoc analyses reported no differences in efficacy of gepants/ditans between responders and non-responders to triptans, but research is hampered by lack of consensus on the definition of non-responder. Due to (partially) overlapping mechanisms of action, it remains unknown whether combination therapy with lasmiditan, gepants and triptans will have added value over monotherapy. Preclinical studies and post-hoc analyses cautiously indicate that these new drugs are safe for patients with cardiovascular risk factors. However, long-term studies are needed to prove cardiovascular safety. The risk of developing medication overuse headache may differ between triptans, ditans and gepants, but further studies are needed to confirm this difference. Head-to-head randomized controlled trials of acute therapies and combinations of therapies are needed to determine their place in migraine treatment among established therapies.

Migraine attacks are of peripheral origin: the debate goes on

BACKGROUND

Despite the pervasiveness of migraine, the underlying pathophysiological mechanisms initiating migraine attacks are far from well understood and are matter of scientific debate.

OBJECTIVE

In this narrative review, we discuss key evidence for that suggest a peripheral origin or central origin and provide directions for future studies that may provide further clarification.

DISCUSSION

Migraine pathogenesis is considered to involve the trigeminovascular system, a term that encompasses the trigeminal nerve and its axonal projections to the intracranial blood vessels. Beyond any doubt both peripheral and central mechanisms are involved in migraine pathogenesis, but an unresolved question is the how the initial activation occurs in a migraine attack. Evidence favoring a peripheral origin of migraine attacks, i.e., initial events occur outside of the blood-brain barrier, include the importance of sensitization of perivascular sensory afferents early on in a migraine attack. Evidence favoring a central origin include the occurrence of prodromal symptoms, migraine aura, and activation of structures within the central nervous system early in and during a migraine attack.

CONCLUSIONS

Both peripheral and central mechanisms are likely involved in a migraine attack, e.g., peripheral nociceptive input is necessary for pain transmission and cortical activity is necessary for pain perception. Yet, the debate of whether migraine attacks are initiated a peripheral or central site remains unresolved. The increased focus on prodromal symptoms and on the development of a human model of migraine aura will possibly provide key arguments needed to answer this question in the near future. Until then, we cannot draw firm conclusions and the debate goes on.

VIDEO LINK

Video recording of the debate held at the 1st International Conference on Advances in Migraine Sciences (ICAMS 2022, Copenhagen, Denmark) is available at: https://www.youtube.com/watch?v=NC0nlcKohz0 .

Safety Findings in Lasmiditan as a Novel Acute Treatment of Migraine in Chinese Patients: A Post Hoc Analysis of the Randomized Controlled Phase 3 CENTURION Trial

INTRODUCTION

Lasmiditan is the first 5-HT_1F receptor agonist with potential to address the huge unmet medical needs for the treatment of migraine in China. The CENTURION study was the first phase 3 study of lasmiditan in Caucasian and Chinese patients with migraine. This post hoc analysis further demonstrates the safety profile of lasmiditan in the Chinese population and was urgently needed.

METHODS

Patients were randomized 1:1:1 to lasmiditan 200 mg lasmiditan 100 mg, or a control group. The incidence of treatment-emergent adverse events (TEAEs), their severity, and incidence by treated attacks for frequently reported TEAEs (≥ 5%) were evaluated. The duration, onset, and relationship of efficacy with very common TEAEs (≥ 10%) was analyzed.

RESULTS

A total of 281 Chinese patients were included in this post hoc analysis. No deaths and no study drug-related treatment emergent serious adverse events (TESAEs) were reported. The incidence of at least one TEAE was higher in patients receiving lasmiditan 200 mg (73.9%) and 100 mg (66.3%) versus placebo (26.6%). TEAEs were generally mild or moderate in severity, and the incidence of frequently reported TEAEs was generally highest during the first attack. Very common TEAEs with lasmiditan included dizziness, asthenia, somnolence, muscular weakness, fatigue, and nausea. The duration of dizziness was longest during the first attack. There were no cardio-cerebrovascular ischemic events and serotonin syndrome. The presence of very common TEAEs (except nausea), and severe dizziness, did not appear to have a negative influence on the efficacy.

CONCLUSION

In the Chinese population of the CENTURION study, most of the TEAEs were neurologic, of mild or moderate severity, and self-limiting. The distribution of frequently reported TEAEs at the first attack differed from the primary cohort, while the overall safety profile of lasmiditan in the Chinese population was generally consistent with the CENTURION primary cohort. No new safety concerns were observed in the Chinese population.

TRIAL REGISTRATION

NCT03670810.

Vascular Risk Score and Associations With Past, Current, or Future Migraine in Women: Cohort Study

BACKGROUND AND OBJECTIVES

Migraine has consistently been associated with an increased risk of cardiovascular disease (CVD) events. It remains, however, unclear to what extent cardiovascular risk profiles might be linked with migraine activity status and how these profiles relate to the development of migraine.

METHODS

We used data from a cohort study of female health professionals (Women's Health Study, n = 27,539, age ≥45 years at baseline) without a history of CVD or other major diseases and who provided a blood sample at baseline. Framingham risk scores (FRSs) estimating the 10-year risk of coronary heart disease calculated at baseline were used to create vascular risk categories. The presence or development of self-reported migraine was assessed by questionnaires. Women were classified as having no migraine, history of migraine (experienced migraine in the past but did not experience any migraine attacks in the year before enrollment), active migraine at baseline (active), or incident migraine (first report of migraine during follow-up but not at baseline). We used multinomial logistic regression models to calculate ORs for the association between FRS categories and migraine status.

RESULTS

Of the 27,539 participants, a total of 21,927 women did not report migraine, 1,500 women reported a history of migraine, 3,579 had migraine at baseline, and 533 reported migraine for the first time during follow-up. The odds of the probability of having a history of migraine at baseline (vs never migraine) was 76% higher among those with FRS ≥10% compared with FRS ≤1% after adjustment (OR = 1.76, 95% CI 1.39-2.23). In contrast, having FRS ≥10% was associated with reduced odds of having active migraine at baseline (OR = 0.64, 95% CI 0.52-0.80) and with newly reported migraine during follow-up (OR = 0.42, 95% CI 0.22-0.81) when compared with women with FRS category ≤1% and those not reporting migraine. A similar association pattern was observed for FRS categories 5%-9% and 2%-4%.

DISCUSSION

High FRS categories were only observed among women with a history of migraine but not with active migraine at baseline or incident migraine after baseline. Our results suggest that the life course of migraine should be considered when studying associations with the vascular system. Our data further suggest that a relatively healthy vascular system, as assessed by the FRS, is associated with active migraine status or developing migraine in the future.

Ditans: a new prospective for the therapy of migraine attack?

INTRODUCTION

Migraine attack is characterized by disabling pain and associated symptoms. Triptans represent the "gold standard" therapy, but cardiac subjects have significant limitations for this approach. New drug families are under consideration to expand therapeutic offerings, especially in the presence of contraindications or for non-responsive patients. This review aimed to analyze studies related to the category of "ditans," with a focus on lasmiditan, which is available for human use.

MATERIALS AND METHODS

We consulted PubMed/MEDLINE, Web of Science, and www.

CLINICALTRIALS

gov to find both original and review articles on the mechanism of action of 5-HT1F agonists in migraine, and for randomized, double-blind, placebo-controlled trials (RCTs) on the family of drugs called "ditans," with a focus on "lasmiditan," published in the time frame of 01-Jan-2010 to 31-Mar-2022. Only studies conducted in human subjects and published in English were included in this review.

RESULTS

We retrieved four RCTs (named SAMURAI, SPARTAN, GLADIATOR, and CENTURION) and several studies that analyzed the efficacy and safety of lasmiditan. Lasmiditan at increasing doses showed significant improvement in pain and most other troublesome symptoms at 2 h. Adverse events were mild and mainly represented by dizziness, vertigo, drowsiness, and fatigue. No vasoconstrictive effects were described, suggesting the use of ditans as a safe option in chronic cardio- and cerebro-vascular disease.

DISCUSSION

Lasmiditan could be a viable alternative to triptans, although further RCT studies and real-world evidence are needed to better understand its potential and possible adverse events in a larger population.

Trigeminovascular effects of propranolol in men and women, role for sex steroids

Objective

Assess whether propranolol modulates the trigeminovascular system in both men and women.

Methods

We investigated the effect of propranolol (80 mg, 90 min after oral administration, corresponding to T_max) on the increase in dermal blood flow of the forehead skin (innervated by the trigeminal nerve) by capsaicin application (0.6 mg/mL) and electrical stimulation (0.2–1.0 mA) before and after placebo (grapefruit juice) or propranolol (oral solution diluted in grapefruit juice) in a randomized, double‐blind, placebo‐controlled cross‐over study, including healthy males (n = 10) and females on contraceptives (n = 11). Additionally, we compared our results with data from the Dutch IADB.nl prescription database by analyzing the change in triptan use after propranolol prescription in a population similar to our dermal blood flow study subjects (males and females, 20–39 years old).

Results

Dermal blood flow responses to capsaicin were significantly attenuated after propranolol, but not after placebo. When stratifying by sex, no significant changes in the capsaicin‐induced dermal blood flow were observed in females after propranolol, whereas they remained significant in males. Dermal blood flow responses to electrical stimulation were not modified in any case. In our prescription database study, after propranolol, a more pronounced decrease in triptan use was observed in male patients than in female patients.

Interpretation

Propranolol (80 mg) inhibits capsaicin‐induced increases in dermal blood flow in a sex‐dependent manner. In patients, a more pronounced decrease in triptan use is observed in males when compared with females, suggesting an interaction between propranolol and sex steroids in the modulation of the trigeminovascular system.

Headache: Treatment update

Primary headache disorders in particular migraine are one of the most common causes of disability worldwide. Given the high burden of migraine in terms of disability, there has been an effort to develop migraine specific therapies that has led to the availability of new drugs including 5HT_1F receptor agonists-ditans (lasmiditan), small molecule calcitonin gene-related peptide (CGRP) receptor antagonists-gepants: (ubrogepant, rimegepant, atogepant) and anti-CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab and eptinezumab). However, some of these treatments incur a high cost and may not be a feasible option for most patients in resource limited settings. Lasmiditan and the gepants are a good option for patients with moderate-severe migraine attacks who cannot use triptans due variously to poor tolerability, or cardio- or cerebrovascular disease. For practical purposes, the new anti-CGRP monoclonal antibodies are best reserved for patients who have failed to have efficacy or had intolerable side effects from multiple traditional oral preventives.

Long COVID headache

Headache is among the most frequent symptoms persisting or newly developing after coronavirus disease 2019 (COVID-19) as part of the so-called long COVID syndrome. The knowledge on long COVID headache is still limited, however growing evidence is defining the features of this novel condition, in particular regarding clinical characteristics, some pathophysiological mechanisms and first treatment recommendations. Long COVID headache can present in the form of worsening of a preexisting primary headache, or, more specifically, in the form of a new (intermittent or daily) headache starting during the acute infection or after a delay. It often presents together with other long COVID symptoms, most frequently with hyposmia. It can manifest with a migrainous or, more frequently, with a tension-type-like phenotype. Persistent activation of the immune system and trigeminovascular activation are thought to play a role. As there are virtually no treatment studies, treatment currently is largely guided by the existing guidelines for primary headaches with the corresponding phenotype. The present report, a collaborative work of the international group of the Junior Editorial Board of The Journal of Headache and Pain aims to summarize the most recent evidence about long COVID headache and suggests approaches to the diagnosis and treatment of this disorder.

Recent Advances and Updates in Trigeminal Autonomic Cephalalgias

Trigeminal autonomic cephalalgias (TACs) are discrete primary headache disorders, characterized by severe unilateral head pain, typically trigeminal distribution, with ipsilateral cranial autonomic symptoms. The conditions within this group are hemicrania continua, cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache with autonomic symptoms. Several advances have been made in understanding the pathogenesis and evolving treatment options in TACs. This review will outline the advances and updates in each TAC.

Cardiovascular Disease and Migraine: Are the New Treatments Safe?

PURPOSE OF REVIEW

The authors present data on cardiovascular safety for the new acute and preventive migraine treatments including ditans, gepants, and calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) alongside older medications like triptans and ergotamines.

RECENT FINDINGS

The authors conclude that there are no cardiovascular safety concerns for lasmiditan, and that it could be used in those with cardiovascular disease. In fact, the literature even suggests that triptans are safer in cardiovascular disease than their contraindications may suggest. At this time, there is insufficient evidence that gepants and CGRP mAbs should be contraindicated in those with cardiovascular disease including stroke or myocardial infarction, though erenumab has now been associated with hypertension. Vasodilation may be an important CGRP-mediated mechanism mid-ischemia especially in patients with small vessel disease; hence, CGRP antagonists should be use with caution in this context. Long-term data is still needed, and prescribers should ensure patients are aware of the limitations of our knowledge at this time, while still offering these effective and well-tolerated treatment options.

Efficacy and Safety of Lasmiditan as a Novel Acute Treatment in Chinese Patients with Migraine: A Subpopulation Analysis of the Randomized Controlled Phase 3 CENTURION Trial

Introduction

Over the last two decades, there has been no novel acute treatment for migraine to address the large unmet medical need in Chinese patients. Lasmiditan, a novel selective serotonin 1F receptor agonist (ditan), is anticipated to bring clinical benefit in Chinese patients with migraine. The CENTURION study is a multi-country, placebo-controlled phase 3 study designed to assess the first attack efficacy and the consistency of response of lasmiditan in acute treatment of migraine. This subpopulation analysis pooled Chinese patients’ data from the primary cohort and additional extended enrollment cohort which was not published previously. This is the first analysis focusing on lasmiditan’s efficacy and safety in Chinese patients with migraine and aims to provide relevant evidence for Chinese physicians.

Methods

Patients were randomized 1:1:1 to one of the three treatment groups for four attacks: (a) lasmiditan 100 mg; (b) lasmiditan 200 mg; or (c) control group. Primary endpoints were pain freedom at 2 h (first attack) and pain freedom at 2 h in at least two out of three attacks. Secondary endpoints included pain relief, sustained pain freedom, and disability freedom.

Results

In total, 281 Chinese patients (lasmiditan 100 mg, 95; lasmiditan 200 mg, 92; control, 94) were treated for at least one migraine attack. Both doses of lasmiditan showed improvement versus placebo for pain freedom at 2 h after first attack, with lasmiditan 200 mg showing nominal significance. An early onset of effect was observed with lasmiditan versus placebo. Both doses of lasmiditan showed better results for all key secondary endpoints versus placebo. The most commonly reported treatment-emergent adverse event across all groups was dizziness.

Conclusion

In the Chinese population, lasmiditan was better than placebo for both primary endpoints and key secondary endpoints with an acceptable safety profile. No new safety signals were detected in the Chinese population. These findings are generally consistent with those observed in the CENTURION study published data and the established product profile.

Trial Registration Number

NCT03670810.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-022-00369-1.

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 history and response to lasmiditan across racial and ethnic groups

OBJECTIVE

The robust enrollment in SPARTAN and SAMURAI provided the opportunity to present post-hoc descriptive details on migraine disease characteristics and treatment outcomes after treatment with lasmiditan, a selective serotonin (5-HT_1F) receptor agonist, in racial and ethnic subgroups.

METHODS

Descriptive data from racial (White [W](n = 3471) and Black or African American [AA](n = 792)) and ethnic (Hispanic or Latinx [HL](n = 775) and Non-Hispanic or Latinx [Non-HL](n = 3637)) populations are presented on pooled data from two double-blind, placebo-controlled, randomized Phase 3 studies (SAMURAI [NCT02439320] and SPARTAN [NCT2605174]). Patients were treated with lasmiditan (50 (SPARTAN only), 100, or 200 mg) or placebo for a single migraine attack of moderate-to-severe intensity. Efficacy data were recorded in an electronic diary at baseline, 30, 60, 90, and 120 min. Safety was evaluated and reported by occurrences of adverse events.

RESULTS

Clinical characteristics were generally similar across populations. W participants had longer migraine history than AA participants, and Non-HL participants had more migraine disability than HL participants. In the lasmiditan single-attack studies, AA participants waited longer than W participants to take study drug. A higher proportion of HL participants rated baseline migraine severity as severe compared to Non-HL participants. Response to lasmiditan was similar across racial and ethnic groups, including pain response, freedom from most bothersome symptom and migraine-related disability, and safety and tolerability. Across multiple outcomes, AA and HL participants tended to report more positive outcomes.

CONCLUSIONS

There were few differences in demographic and clinical characteristics across racial and ethnic groups. Similar lasmiditan efficacy and safety outcomes were observed in AA versus W participants, and in HL versus Non-HL participants. Small observed differences may be driven by a tendency toward a more positive response observed across all treatment groups by AA and HL participants.

Migraine

Migraine is a common, chronic, disorder that is typically characterized by recurrent disabling attacks of headache and accompanying symptoms, including aura. The aetiology is multifactorial with rare monogenic variants. Depression, epilepsy, stroke and myocardial infarction are comorbid diseases. Spreading depolarization probably causes aura and possibly also triggers trigeminal sensory activation, the underlying mechanism for the headache. Despite earlier beliefs, vasodilation is only a secondary phenomenon and vasoconstriction is not essential for antimigraine efficacy. Management includes analgesics or NSAIDs for mild attacks, and, for moderate or severe attacks, triptans or 5HT_1B/1D receptor agonists. Because of cardiovascular safety concerns, unreliable efficacy and tolerability issues, use of ergots to abort attacks has nearly vanished in most countries. CGRP receptor antagonists (gepants) and lasmiditan, a selective 5HT1_F receptor agonist, have emerged as effective acute treatments. Intramuscular onabotulinumtoxinA may be helpful in chronic migraine (migraine on ≥15 days per month) and monoclonal antibodies targeting CGRP or its receptor, as well as two gepants, have proven effective and well tolerated for the preventive treatment of migraine. Several neuromodulation modalities have been approved for acute and/or preventive migraine treatment. The emergence of new treatment targets and therapies illustrates the bright future for migraine management.

Parenchymal neuroinflammatory signaling and dural neurogenic inflammation in migraine

Background

Pain is generally concomitant with an inflammatory reaction at the site where the nociceptive fibers are activated. Rodent studies suggest that a sterile meningeal inflammatory signaling cascade may play a role in migraine headache as well. Experimental studies also suggest that a parenchymal inflammatory signaling cascade may report the non-homeostatic conditions in brain to the meninges to induce headache. However, how these signaling mechanisms function in patients is unclear and debated. Our aim is to discuss the role of inflammatory signaling in migraine pathophysiology in light of recent developments.

Body

Rodent studies suggest that a sterile meningeal inflammatory reaction can be initiated by release of peptides from active trigeminocervical C-fibers and stimulation of resident macrophages and dendritic/mast cells. This inflammatory reaction might be needed for sustained stimulation and sensitization of meningeal nociceptors after initial activation along with ganglionic and central mechanisms. Most migraines likely have cerebral origin as suggested by prodromal neurologic symptoms. Based on rodent studies, a parenchymal inflammatory signaling cascade has been proposed as a potential mechanism linking cortical spreading depolarization (CSD) to meningeal nociception. A recent PET/MRI study using a sensitive inflammation marker showed the presence of meningeal inflammatory activity in migraine with aura patients over the occipital cortex generating the visual aura. These studies also suggest the presence of a parenchymal inflammatory activity, supporting the experimental findings. In rodents, parenchymal inflammatory signaling has also been shown to be activated by migraine triggers such as sleep deprivation without requiring a CSD because of the resultant transcriptional changes, predisposing to inadequate synaptic energy supply during intense excitatory transmission. Thus, it may be hypothesized that neuronal stress created by either CSD or synaptic activity-energy mismatch could both initiate a parenchymal inflammatory signaling cascade, propagating to the meninges, where it is converted to a lasting headache with or without aura.

Conclusion

Experimental studies in animals and emerging imaging findings from patients warrant further research to gain deeper insight to the complex role of inflammatory signaling in headache generation in migraine.

Lasmiditan efficacy in the acute treatment of migraine was independent of prior response to triptans: Findings from the CENTURION study

BACKGROUND

A significant proportion of triptan users exhibit an insufficient response or inadequate tolerability to a triptan, and some may develop a contraindication. Lasmiditan, a selective 5-HT_1F receptor agonist, may be an option for these individuals. We assessed lasmiditan efficacy in a subgroup of patients in CENTURION (Phase 3 migraine consistency study) who exhibited an insufficient response to triptans, including a subgroup with insufficient response due to efficacy only.

METHODS

Patients were randomized to lasmiditan 200 mg for four attacks, lasmiditan 100 mg for four attacks, or placebo for three and lasmiditan 50 mg for one attack. Triptan insufficient responders were pre-defined as patients with insufficient efficacy or tolerability, or who developed a contraindication.

RESULTS

In triptan insufficient responders, lasmiditan was superior to placebo (p < 0.05) for pain freedom beginning at 1 h (both doses); pain relief beginning at 0.5 (200 mg) or 1 h (100 mg); migraine-related disability freedom, much/very much better on the Patient Global Impression of Change, and most bothersome symptom freedom at 2 h; sustained pain freedom; and need for rescue medication. Lasmiditan showed benefit for consistency of effect across attacks for 2-h pain freedom and pain relief. Findings were similar in triptan responders and triptan naïve patients and when the triptan insufficient response definition was based on efficacy only.

CONCLUSIONS

Lasmiditan was efficacious across multiple clinically relevant endpoints in the acute treatment of migraine independent of prior response to triptans.Trial Registration: CENTURION (NCT03670810); SAMURAI (NCT02439320); SPARTAN (NCT02605174).

The impact of CGRPergic monoclonal antibodies on prophylactic antimigraine therapy and potential adverse events

Migraine is a prevalent medical condition and the second most disabling neurological disorder. Regarding its pathophysiology, calcitonin gene-related peptide (CGRP) plays a key role, and, consequently, specific antimigraine pharmacotherapy has been designed to target this system. Hence, apart from the gepants, the recently developed monoclonal antibodies (mAbs) are a novel approach to treat this disorder. In this review we consider the current knowledge on the mechanisms of action, specificity, safety, and efficacy of the above mAbs as prophylactic antimigraine agents, and examine the possible adverse events that these agents may trigger. Antimigraine mAbs act as direct scavengers of CGRP (galcanezumab, fremanezumab, and eptinezumab) or against the CGRP receptor (erenumab). Due to their long half-lives, these molecules have revolutionized the prophylactic treatment of this neurovascular disorder. Moreover, because of their physicochemical properties, these agents are hepato-friendly and do not cross the blood-brain barrier (highlighting the relevance of peripheral mechanisms in migraine). Nevertheless, apart from potential cardiovascular side effects, the interaction with AMY₁ receptors and immunogenicity induced by autoantibodies against mAbs could be a concern for the safety of long-term treatment with these molecules.

The locus of Action of CGRPergic Monoclonal Antibodies Against Migraine: Peripheral Over Central Mechanisms

Migraine is a complex neurovascular disorder characterized by attacks of moderate to severe unilateral headache, accompanied by photophobia among other neurological signs. Although an arsenal of antimigraine agents is currently available in the market, not all patients respond to them. As Calcitonin Gene-Related Peptide (CGRP) plays a key role in the pathophysiology of migraine, CGRP receptor antagonists (gepants) have been developed. Unfortunately, further pharmaceutical development (for olcegepant and telcagepant) was interrupted due to pharmacokinetic issues observed during the Randomized Clinical Trials (RCT). On this basis, the use of monoclonal antibodies (mAbs; immunoglobulins) against CGRP or its receptor has recently emerged as a novel pharmacotherapy to treat migraines. RCT showed that these mAbs are effective against migraines producing fewer adverse events. Presently, the U.S. Food and Drug Administration approved four mAbs, namely: (i) erenumab; (ii) fremanezumab; (iii) galcanezumab; and (iv) eptinezumab. In general, specific antimigraine compounds exert their action in the trigeminovascular system, but the locus of action (peripheral vs. central) of the mAbs remains elusive. Since these mAbs have a molecular weight of ∼150 kDa, some studies rule out the relevance of their central actions as they seem unlikely to cross the Blood-Brain Barrier (BBB). Considering the therapeutic relevance of this new class of antimigraine compounds, the present review has attempted to summarize and discuss the current evidence on the probable sites of action of these mAbs.

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.

A Continuous Flow Process for LSN647712 via Double Organometallic Additions to Dimethylcarbamyl Chloride

The ketone intermediate LSN647712 is a key synthetic intermediate for the drug substance lasmiditan manufacturing process. A three-step connected continuous flow process utilizing a Turbo Grignard reagent, N-methylpiperidin-4-ylmagnesium chloride, and lithiated 2,6-dibromopyridine sequentially added to double electrophile (O═C(++) synthon dimethylcarbamyl chloride (DMCC) was developed to deliver the ketone intermediate in a high chemical yield (>85%). This highly productive (>100 g/h lab system) and intensified process (τ ∼ 3 min) yields the product in high purity upon batch reactive crystallization to form a corresponding hydrobromide salt. In addition to the connected plug flow reactor system, the Grignard reagent, N-methylpiperidin-4-ylmagnesium chloride, was also prepared continuously in CSTR as a more soluble LiCl adduct in THF (Turbo Grignard).

Pharmacological, Pharmacokinetic, Pharmacodynamic and Physicochemical Characterization of FE 205030: A Potent, Fast Acting, Injectable CGRP Receptor Antagonist for the Treatment of Acute Episodic Migraine

The neuropeptide calcitonin gene-related peptide (CGRP) is known to play a central role in the underlying pathophysiology of migraine. In comparison to the effective triptan class of antimigraine treatments, the CGRP antagonists possess a comparable efficacy but a superior cardiovascular safety profile in patients. This paper describes the development of selective and potent peptidic CGRP antagonist, FE 205030, that has a fast onset of action and an optimal half-life (subcutaneous T_max ~ 60 min, and t_1/2 ~ 4.4 h in 80 kg pigs, respectively), which is key to prevention of the progression of debilitating migraine symptoms. The in vivo efficacy of this agent has been established a translational pharmacodynamic model (inhibition of capsaicin-induced increase in skin blood flow) in cynomolgus monkeys and shows maximal inhibitory activity at circulating concentrations of 30-100 nM. Antagonist activity of FE 205030 was characterized on CGRP-induced vasodilation in isolated human mesenteric resistance arteries in an ex vivo isometric myograph study, and FE 205030 effectively blocked CGRP-induced vasodilation with a pA₂ of 9.3 ± 0.1, mean ± standard error. Multispecies allometric scaling and modeling of subcutaneous (SC) effective concentrations indicates that a dose of 10-30 mg/day is sufficient to achieve a drug exposure/target coverage of 8h, which is useful to prevent migraine recurrence in patients. The molecule also possesses appropriate physicochemical properties that allows for a convenient dosing form factor of 1 ml injection volume with a sufficient solubility and acceptable short-term stability, optimal for treatment of acute migraine episodes in patients. Hence, FE 205030 may provide an important fast-acting injectable option for patients suffering from frequent acute migraine episodes, complementary to preventative monoclonal antibodies and oral small molecule CGRP-R antagonist therapies.

Vortex-assisted dispersive solid phase microextraction using Fe3O4/FeOOH magnetic nanocomposites for high-performance thin-layer chromatographic determination of zolmitriptan in rabbit plasma samples

In this work, a fast, versatile, and convenient dispersive solid-phase micro-extraction (DSPME) method is combined with a spectro-densitometric technique for the analysis of zolmitriptan (ZOLM) in biological fluids. Fe₃O₄/FeOOH magnetic nanocomposites (MNCs) were prepared by a co-precipitation method in aqueous solutions and utilized subsequently as a sorbent in DSPME. By coupling DSPME with high-performance thin-layer chromatography (HPTLC) with fluorescence detection, the preconcentration and determination of (ZOLM) in presence of metoclopramide (MET) and paracetamol (PARA), which are prescribed as an adjuvant therapy with ZOLM, was accomplished. Adsorption capability was assessed using both Langmuir and Freundlich adsorption isotherm models. The adsorption data was fitted to Langmuir adsorption isotherm model as reflected by high determination coefficient (R² = 0.9944). Moreover, adsorption kinetics was assessed by pseudo-first and pseudo-second order kinetic models. The data was fitted to pseudo-second order kinetics, which proves that ZOLM interaction with the adsorbent is a chemisorption process. Surface complexation with MNCs was suggested to explain the pH dependence of ZOLM sorption. The key parameters of extraction and desorption steps (including pH, extraction time, sample volume, magnetic adsorbent amount, and desorption circumstances) were evaluated. Optimized conditions for solid phase microextraction of ZOLM were pH 2.9, 5.0 mg Fe₃O₄/FeOOH MNCs, 15 min vortex-assisted extraction time and 3 × 200 μL of methanol: 33% ammonia; 4:1 as eluent. The analysis was achieved using ACN: dichloromethane: 33% ammonia (22.5: 6.0: 1.5, v/v/v) as a mobile phase and the fluorescence detection was carried out at 223 nm. The proposed DSPME method was successfully applied for trace quantification of ZOLM in rabbits' plasma (n = 6) after oral administration with a linearity range of 50.0 - 400.0 ng mL^-1 (R² = 0.9931), a detection limit of 12.0 ng mL^-1 and extraction recovery of 97.27-99.89% with an RSD < 2% (n = 9). Moreover, the selectivity of the proposed approach for analysis of ZOLM in the presence of MET and PARA is demonstrated.

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.

Phase 2 randomized placebo-controlled study of lasmiditan for the acute treatment of migraine in Japanese patients

Objective

To evaluate the efficacy and safety of lasmiditan in Japanese adults with migraine.

Background

Global clinical studies have demonstrated the efficacy and safety of lasmiditan in the acute treatment of migraine.

Methods

This was a multicenter, randomized, double‐blind, placebo‐controlled, phase 2 study in Japan (NCT03962738), which enrolled adults with migraine with or without aura. Participants were randomized 7:3:7:6 to placebo, lasmiditan 50 mg, 100 mg, or 200 mg to be self‐administered orally within 4 h of onset of a single moderate‐to‐severe migraine attack. Participants recorded their response to treatment prior to dosing and for 48 h postdose. The primary endpoint was headache pain freedom at 2 h postdose.

Results

Participants (N = 846) were randomized and treated (N = 691, safety; N = 682, modified intent‐to‐treat). At 2 h postdose, a significantly higher proportion of participants were headache pain‐free in the lasmiditan 200 mg (40.8%, 73/179; odds ratio 3.46 [95% confidence interval 2.17 to 5.54]; p < 0.001; primary objective) and 100 mg groups (32.4%, 67/207; odds ratio 2.41 [1.51 to 3.83]; p < 0.001) compared with the placebo group (16.6%, 35/211), whereas the lasmiditan 50 mg group had a numerically higher proportion of participants headache pain‐free (23.5%, 20/85; odds ratio 1.55 [0.83 to 2.87]; p = 0.167) compared with placebo. A statistically significant linear dose–response relationship for pain freedom was achieved at 2 h by a Cochran–Armitage trend test (p < 0.001). Lasmiditan treatment was also associated with headache pain relief, most bothersome symptom freedom, and improvement on disability and Patient Global Impression of Change outcomes. The majority of treatment‐emergent adverse events were mild and of short duration, the most common of which were dizziness (39.4%; 188/477), somnolence (19.3%; 92/477), and malaise (10.5%; 50/477) in all lasmiditan groups, with no serious adverse events reported.

Conclusions

Lasmiditan was well tolerated and effective for the acute treatment of Japanese patients with migraine, consistent with global phase 3 studies.

Lasmiditan inhibits calcitonin gene-related peptide release in the rodent trigeminovascular system

Lasmiditan, an antimigraine drug with selective 5-HT_1F receptor affinity, prejunctionally inhibits calcitonin gene-related peptide release in peripheral and central trigeminal nerve terminals of rodents.

Migraine headache pathophysiology involves trigeminovascular system activation, calcitonin gene-related peptide (CGRP) release, and dysfunctional nociceptive transmission. Triptans are 5-HT_1B/1D/(1F) receptor agonists that prejunctionally inhibit trigeminal CGRP release, but their vasoconstrictor properties limit their use in migraine patients with cardiovascular disease. By contrast, lasmiditan is a novel antimigraine and selective 5-HT_1F receptor agonist devoid of vasoconstrictor properties. On this basis, this study has investigated the modulation of trigeminal CGRP release by lasmiditan. For this purpose, we have comparatively analysed the inhibition of several components of the trigeminovascular system induced by lasmiditan and sumatriptan through: ex vivo KCl-induced CGRP release from isolated dura mater, trigeminal ganglion, and trigeminal nucleus caudalis of mice; and in vivo dural vasodilation in the rat closed-cranial window model induced by endogenous (electrical stimulation and capsaicin) and exogenous CGRP. The ex vivo release of CGRP was similarly inhibited by sumatriptan and lasmiditan in all trigeminovascular system components. In vivo, intravenous (i.v.) lasmiditan or higher doses of sumatriptan significantly attenuated the vasodilatory responses to endogenous CGRP release, but not exogenous CGRP effects. These data suggest that lasmiditan prejunctionally inhibits CGRP release in peripheral and central trigeminal nerve terminals. Because lasmiditan is a lipophilic drug that crosses the blood–brain barrier, additional central sites of action remain to be determined.

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.

Optimal Dosing of Lasmiditan in the Management of Acute Migraine Attack: A Systematic Review and Meta-analysis

Background

The current target of migraine treatment is focused on Triptans. Lasmiditan, a non-vasoconstrictive and highly selective 5HT_1F receptor agonist is a novel therapeutic discovery for migraine for patients with cardiovascular (CV) risk factors or stable cardiovascular diseases and who fail to respond to the existing treatment.

Objective

To identify an optimal dosing of Lasmiditan 100 mg versus 200 mg for the treatment of acute migraine attacks in adult patients with cardiovascular risk factors.

Methods

Systematic searches were run in databases such as Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Google scholar, and PUBMED. Out of 83 study records identified, two studies were included for quantitative analysis.

Results

There was a significant headache pain freedom at 2 h [Odds Ratio (OR): 0.77; 95% Confidence interval (CI): 0.64-0.92] and sustained pain freedom at 24 h (OR): 0.75; 95% CI: 0.61-0.93] in patients taking Lasmiditan 200 mg compared to those taking Lasmiditan 100 mg. The results were statistically insignificant for parameters like most bothersome symptoms (MBS) free at 2 h, headache relief at 2 h, disability level at 2 h, and global impression of change at 2 h. A combined analysis of these parameters showed a remarkable difference between both the groups favoring Lasmiditan 200 mg [OR: 0.88; 95% CI: 0.81-0.95].

Conclusion

An oral dosing of Lasmiditan 200 mg is ideal for the treatment of acute migraine in adult patients with CV risk factors for attaining headache pain freedom at 2 h and sustained pain freedom at 24 compared to Lasmiditan 100 mg.

Effect of a change in lasmiditan dose on efficacy and safety in patients with migraine

Background: Lasmiditan is a selective serotonin (1F) receptor agonist approved for acute treatment of migraine with 3 doses: 50, 100, and 200 mg.Objective: To help provide dosing insights, we assessed the efficacy and safety of lasmiditan in patients who treated two migraine attacks with the same or different lasmiditan doses.Methods: Integrated analyses used data from the migraine attack treated in either of two controlled, Phase 3, single attack studies (SAMURAI/SPARTAN), and after the first attack treated in the open-label GLADIATOR extension study. Eight patient groups were created based on the initial dose received in SAMURAI or SPARTAN and the subsequent dose in GLADIATOR: placebo-100, placebo-200, 50-100, 50-200, 100-100, 100-200, 200-100, 200-200. Migraine pain freedom, migraine-related functional disability freedom, most bothersome symptom (MBS) freedom, and pain relief were evaluated at 2-h post-dose. The occurrence of most common treatment-emergent adverse events (MC-TEAE) was evaluated. Shift analyses were performed for pain freedom and ≥1 MC-TEAE. The incidence of patients with a specific outcome from the first and subsequent doses were compared within each dose change group using McNemar's test.Results: Small, but consistent, increases in incidences of pain freedom, migraine-related functional disability freedom, MBS freedom, and pain relief occurred when the second lasmiditan dose was higher than the initial dose. For patients starting on 50 mg, increasing to 100 or 200 mg provided a positive efficacy-TEAE balance, despite an increase in incidence of ≥1 MC-TEAE. For patients starting on 100 mg, increasing to 200 mg provided a positive efficacy-TEAE balance. If the initial dose was 100 or 200 mg, the incidence of patients experiencing ≥1 MC-TEAE decreased or stayed the same with their subsequent dose, regardless of dose. Decreasing from 200 to 100 mg led to a decrease in patients with pain freedom and ≥1 MC-TEAE, resulting in a neutral efficacy-TEAE balance. Shift analyses supported these findings.Conclusion: A positive efficacy-TEAE balance exists for patients increasing their lasmiditan dose for treatment of a subsequent migraine attack. These results could be important for optimizing dosing for individual patients.Clinicaltrials.gov: SAMURAI (NCT02439320); SPARTAN (NCT02605174); GLADIATOR (NCT02565186).

Rational Use of Lasmiditan for Acute Migraine Treatment in Adults: A Narrative Review

PURPOSE

This narrative review provides an update on the research that led to the development of ditans and lasmiditan for the acute treatment of migraine in adults and discusses the potential advantages and disadvantages of lasmiditan in clinical use.

METHODS

The electronic databases PubMed, Scopus, and ClinicalTrials.gov were searched from database inception through January 9, 2021, to identify relevant studies. Search results were assessed for their overall relevance to this review.

FINDINGS

Because part of the effect of the triptans is mediated by the serotonin 1F receptors, which are not present in the smooth muscle, a pure agonist of these receptors, lasmiditan, was developed. Lasmiditan is hypothesized to act on antinociceptive pathways and inhibit the calcitonin gene-related peptide release. Lasmiditan was approved by the US Food and Drug Administration in 2019 based on the results of 2 pivotal trials that found a significant difference from placebo in the percentage of patients who achieved freedom from pain and most bothersome symptom at 2 h. The main concern of lasmiditan derives from its central nervous system-related adverse effects, mainly dizziness and paraesthesia, probably attributable to its high blood brain barrier penetration. These central nervous system adverse effects impair driving performance for hours and might be suboptimal for individuals with migraine who want to quickly stop the migraine attack to resume their activities as soon as possible.

IMPLICATIONS

Despite the advantage of being beneficial in the acute treatment of migraine without vasocostrictive action, lasmiditan also presents limitations, in particular the central nervous system adverse effects. Moreover, head-to-head trials against triptans and gepants are indispensable to determine the better option for patients.

Subcutaneous sumatriptan: association with decreases in postoperative pain and opioid use after elective cranial surgery

OBJECTIVE

Sumatriptan, a serotonin receptor agonist, has been used in the management of primary headache disorders and has been shown to affect trigeminal dural afferents. There is limited literature on the safety and efficacy of sumatriptan for postcraniotomy pain management. This study aimed to identify whether subcutaneous sumatriptan is a safe and efficacious pain management strategy after elective craniotomy.

METHODS

The authors retrospectively reviewed patients who underwent supratentorial or suboccipital craniotomy between 2016 and 2019 that was performed by a single provider at a single institution to identify patients given subcutaneous sumatriptan in the postoperative period. Pain scores and intravenous and oral opioid use were compared in patients with (n = 15) and without (n = 45) sumatriptan administration.

RESULTS

Patients with and without sumatriptan administration had no significant differences in baseline characteristics or surgery type. There were no sumatriptan-related complications. The average pain score decreased from 3.9 to 1.3 within 1 hour after sumatriptan administration (p = 0.014). In both adult and pediatric patients there was decreased postoperative pain (adults: pain score of 1.1 vs 7.1, p < 0.001; pediatric: 1.1 vs 3.9, p = 0.007) within the first 48 hours. There were decreases in intravenous opioid use, length of intravenous opioid use, maximum dose of intravenous opioid used, oral opioid use, length of oral opioid use, and maximum dose of oral opioid used in both adult and pediatric patients.

CONCLUSIONS

The authors identified subcutaneous sumatriptan as a safe and efficacious tool for postoperative pain management after craniotomy. Large multicenter randomized controlled studies are needed to further evaluate the specific role of sumatriptan in postoperative pain management after craniotomy.

Identifying New Antimigraine Targets: Lessons from Molecular Biology

Primary headaches are one of the most common conditions; migraine being most prevalent. Recent work on the pathophysiology of migraine suggests a mismatch in the communication or tuning of the trigeminovascular system, leading to sensitization and the release of calcitonin gene-related peptide (CGRP). In the current Opinion, we use the up-to-date molecular understanding of mechanisms behind migraine pain, to provide novel aspects on how to modify the system and for the development of future treatments; acute as well as prophylactic. We explore the distribution and the expression of neuropeptides themselves, as well as certain ion channels, and most importantly how they may act in concert as modulators of excitability of both the trigeminal C neurons and the Aδ neurons.