CGRP Receptor Antagonists and 5-HT1F Receptor Agonist in the Treatment of Migraine

CGRP Antagonism and Ketogenic Diet in the Treatment of Migraine

The study of migraine is based on the complexity of the pathology, both at the pathophysiological and epidemiological levels. Although it affects more than a billion people worldwide, it is often underestimated and underreported by patients. Migraine must not be confused with a simple headache; it is a serious and disabling disease that causes considerable limitations in the daily life of afflicted people, including social, work, and emotional effects. Therefore, it causes a daily state of suffering and discomfort. It is important to point out that this pathology not only has a decisive impact on the quality of life of those who suffer from it but also on their families and, more generally, on society as a whole. The clinical picture of migraine is complex, with debilitating unilateral or bilateral head pain, and is often associated with characteristic symptoms such as nausea, vomiting, photophobia, and phonophobia. Hormonal, environmental, psychological, dietary, or other factors can trigger it. The present review focuses on the analysis of the physiopathological and pharmacological aspects of migraine, up to the correct dietary approach, with specific nutritional interventions aimed at modulating the symptoms. Based on the symptoms that the patient experiences, targeted and specific therapy is chosen to reduce the frequency and severity of migraine attacks. Specifically, the role of calcitonin gene-related peptide (CGRP) in the pathogenesis of migraine is analyzed, along with the drugs that effectively target the corresponding receptor. Particularly, CGRP receptor antagonists (gepants) are very effective drugs in the treatment of migraine, given their high diffusion in the brain. Moreover, following a ketogenic diet for only one or two months has been demonstrated to reduce migraine attacks. In this review, we highlight the diverse facets of migraine, from its physiopathological and pharmacological aspects to prevention and therapy.

Consensus-Based Recommendations on the Use of CGRP-Based Therapies for Migraine Prevention in the UAE

INTRODUCTION

Migraine is a common debilitating neurological disorder affecting a large proportion of the general population. Calcitonin gene-related peptide (CGRP), a 37-amino acid neuropeptide, plays a key role in the pathophysiology of migraine, and the development of therapies targeting the anti-CGRP pathway has revolutionized the field of migraine treatment.

METHODS

An expert task force of neurologists in the United Arab Emirates (UAE) developed and critically assessed recommendations on the use of CGRP-based therapies in migraine treatment and management in the UAE, based on available published literature. A consensus was reached for each statement by means of an open-voting process, based on a predefined agreement level of at least 60%.

RESULTS

The consensus recommendations advocate the need for guidelines for the appropriate use of CGRP-based therapies by defining patient cohorts and appropriate monitoring of therapeutic response as well as standardizing the initiation, assessment, and cessation of treatment. The consensus recommendations were primarily formulated on the basis of international studies, because of the limited availability of regional and local data. As such, they may also act as guidelines for global healthcare providers.

CONCLUSIONS

These are the first consensus recommendations for the UAE that address the use of CGRP-based therapies in the treatment and management of migraine, integrating both clinical evidence and medical expertise to enhance clinical judgment and decision-making.

Herbal medicines for insomnia through regulating 5-hydroxytryptamine receptors: a systematic review

Insomnia is a common sleep disorder without effective therapy and can affect a person's life. The mechanism of the disease is not completely understood. Hence, there is a need to understand the targets related to insomnia, in order to develop innovative therapies and new compounds. Recently, increasing interest has been focused on complementary and alternative medicines for treating or preventing insomnia. Research into their molecular components has revealed that their sedative and sleep-promoting properties rely on the interactions with various neurotransmitter systems in the brain. In this review, the role of 5-hydroxytryptamine (5-HT) in insomnia development is summarized, while a systematic analysis of studies is conducted to assess the mechanisms of herbal medicines on different 5-HT receptors subtypes, in order to provide reference for subsequent research.

Safety of drugs used for the treatment of migraine during pregnancy: a narrative review

INTRODUCTION

Migraine is common in females of childbearing age and negatively impacts quality of life. The majority of those with migraine who become pregnant see an improvement in their condition but not all do. Providing evidence-based recommendations for the pharmacological management of migraine in pregnancy is challenging.

AREAS COVERED

This narrative review provides an update on the safety of drugs used for migraine in pregnancy. National and international guidelines on the management of episodic migraine in adults were used to select the drugs of relevance to pregnant women. The final list of drugs was chosen by a pain specialist who categorized them according to drug class and use in acute management or prevention. PubMed was searched from inception to 31st July 2022 for evidence on drug safety.

EXPERT OPINION

Obtaining high-quality drug safety data in pregnant migraineurs is difficult not least because exposing a fetus to research-related risks is often considered unethical. There is reliance on observational studies which often group drugs together and lack specificities pertinent to drug prescribing like timing, dosing and duration. Improved statistical tools, study designs and the creation of international collaborative frameworks are ways to advance knowledge on drug safety in pregnancy.

New Migraine Drugs for Older Adults

Migraine is one of the most widespread and burdensome diseases, affecting one in every seven individuals in the world, for an estimated global prevalence of 14%. Until recently, therapeutic choices for older migraineurs have been limited by safety concerns and such patients have typically been excluded from clinical trials. However, randomized controlled trials (RCTs) of new migraine drugs have begun to include participants aged over 65 years, offering clinicians relevant safety and efficacy data to be able to treat older patients with the newest drug classes, including monoclonal antibodies for CGRP (r), CGRP antagonists, and drugs targeting the serotonin 5-HT_1F receptor. RCT inclusion criteria nonetheless select the most appropriate older patients, usually excluding polymorbid participants. In a real-life setting, older patients may have several comorbidities, and this reduces the clinical applicability of the new drugs to these patients. Two main points should be addressed to solve this barrier: the inclusion of a sufficient number of migraineurs aged over 65 years in RCTs and the publication of appropriate guidelines for a tailored treatment that considers the existence of multimorbid pathologies in this population of individuals.

Gepants for Acute and Preventive Migraine Treatment: A Narrative Review

Calcitonin gene-related peptide (CGRP) antagonists are a class of medications that act as antagonists of the CGRP receptor or ligand. They can be divided into monoclonal antibodies and non-peptide small molecules, also known as gepants. CGRP antagonists were the first oral agents specifically designed to prevent migraines. The second generation of gepants includes rimegepant (BHV-3000, BMS-927711), ubrogepant (MK-1602), and atogepant (AGN-241689, MK-8031). Zavegepant (BHV-3500, BMS-742413) belongs to the third generation of gepants characterized by different administration routes. The chemical and pharmacological properties of this new generation of gepants were calculated. The clinical trials showed that the new generation of CGRP antagonists is effective for the acute and/or preventive treatment of migraines. No increased mortality risks were observed to be associated with the second- and third-generation gepants. Moreover, the majority of the serious adverse events reported probably occurred unrelated to the medications. Interesting facts about gepants were highlighted, such as potency, hepatotoxicity, concomitant use with monoclonal antibodies targeting the CGRP, comparative analysis with triptans, and the "acute and preventive" treatment of migraine. Further studies should include an elderly population and compare the medications inside this class and with triptans. There are still concerns regarding the long-term side effects of these medications, such as chronic vascular hemodynamic impairment. Meanwhile, careful pharmacovigilance and safety monitoring should be performed in the clinical practice use of gepants.

Reaching the Nadir of Medication Overuse in Chronic Migraine

The introduction of new drug classes for chronic migraine, such as monoclonal antibodies for calcitonin-gene-related peptide or its receptor (CGRPr), or antagonists of the same CGRP, have opened a new scenario in a selected population of individuals with migraine, and those presenting with chronic form of migraine in association with medication overuse. Medication overuse is now considered a complication of chronic migraine and, in fact, the treatment with CGRP(r)-MAbs of chronic migraine with medication overuse results in a clinical improvement of chronic migraine itself, accompanied by a parallel and obvious reduction in the intake of specific and non-specific acute migraine drugs. Education on the correct use of these drugs will be an essential tool to reduce the disability and costs of people suffering from CM complicated by MO, considering the long-term safety of the new therapies targeting the CGRP pathways. Only in this way can medication overuse risk can be reduced at its nadir in the scenario of chronicity of migraines.

European Headache Federation (EHF) consensus on the definition of effective treatment of a migraine attack and of triptan failure

Background

Triptans are migraine-specific acute treatments. A well-accepted definition of triptan failure is needed in clinical practice and for research. The primary aim of the present Consensus was to provide a definition of triptan failure. To develop this definition, we deemed necessary to develop as first a consensus definition of effective treatment of an acute migraine attack and of triptan-responder.

Main body

The Consensus process included a preliminary literature review, a Delphi round and a subsequent open discussion. According to the Consensus Panel, effective treatment of a migraine attack is to be defined on patient well-being featured by a) improvement of headache, b) relief of non-pain symptoms and c) absence of adverse events. An attack is considered effectively treated if patient’s well-being, as defined above, is restored within 2 hours and for at least 24 hours. An individual with migraine is considered as triptan-responder when the given triptan leads to effective acute attack treatment in at least three out of four migraine attacks. On the other hand, an individual with migraine is considered triptan non-responder in the presence of failure of a single triptan (not matching the definition of triptan-responder). The Consensus Panel defined an individual with migraine as triptan-resistant in the presence of failure of at least 2 triptans; triptan refractory, in the presence of failure to at least 3 triptans, including subcutaneous formulation; triptan ineligibile in the presence of an acknowledged contraindication to triptan use, as specified in the summary of product characteristics.

Conclusions

The novel definitions can be useful in clinical practice for the assessment of acute attack treatments patients with migraine. They may be helpful in identifying people not responding to triptans and in need for novel acute migraine treatments. The definitions will also be of help in standardizing research on migraine acute care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01502-z.

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.

Applying a biopsychosocial model to migraine: rationale and clinical implications

Migraine is a complex condition in which genetic predisposition interacts with other biological and environmental factors determining its course. A hyperresponsive brain cortex, peripheral and central alterations in pain processing, and comorbidities play a role from an individual biological standpoint. Besides, dysfunctional psychological mechanisms, social and lifestyle factors may intervene and impact on the clinical phenotype of the disease, promote its transformation from episodic into chronic migraine and may increase migraine-related disability.Thus, given the multifactorial origin of the condition, the application of a biopsychosocial approach in the management of migraine could favor therapeutic success. While in chronic pain conditions the biopsychosocial approach is already a mainstay of treatment, in migraine the biomedical approach is still dominant. It is instead advisable to carefully consider the individual with migraine as a whole, in order to plan a tailored treatment. In this review, we first reported an analytical and critical discussion of the biological, psychological, and social factors involved in migraine. Then, we addressed the management implications of the application of a biopsychosocial model discussing how the integration between non-pharmacological management and conventional biomedical treatment may provide advantages to migraine care.

Calcitonin Gene-Related Peptide (CGRP)-Targeted Monoclonal Antibodies and Antagonists in Migraine: Current Evidence and Rationale

Calcitonin gene-related peptide (CGRP), a 37 amino-acid neuropeptide found mostly in peptidergic sensory C-fibers, has been suggested to be implicated in the pathogenesis of migraine, which is one of the most common neurological disorders seen in medical practice, affecting almost 16% of the US population. While previously thought to be a vascular condition, migraine attacks are the result of neurogenic inflammation and peripheral/central sensitization through dysfunctional activation of the trigeminovascular system. To date, two classes of therapeutic agents have been developed to interrupt the function of CGRP: CGRP-targeted monoclonal antibodies (mAbs) and small-molecule antagonists (gepants). There are currently four CGRP-targeted mAbs and three gepants that are US Food and Drug Administration (FDA) approved for the treatment of migraine. Multiple phase II and III studies have established the efficacies and tolerability of these treatments. Previously, we reviewed the fundamental role of CGRP in migraine pathogenesis. Here, we discuss in depth the clinical evidence (randomized controlled trials and real-world studies), safety, and tolerability of CGRP-targeted mAbs and gepants for treating migraine.

Atogepant: an emerging treatment for migraine

INTRODUCTION

Until recently, only nonspecific and not always well-tolerated medications were available for migraine prophylaxis. Currently, specific drugs such as calcitonin gene-related peptide (CGRP) monoclonal antibodies and second-generation gepants are marketed for migraine treatment. Atogepant, an orally active small molecule, is a potent, selective antagonist of the CGRP receptor and is the only gepant authorized exclusively for episodic migraine prophylaxis in adults.

AREAS COVERED

Using literature obtained from PubMed, Scopus, Web of Science, Cochrane, and ClinicalTrials.gov (up to February 13^rd, 2022), the authors summarize and evaluate the available data on atogepant for the prophylaxis of episodic migraine.

EXPERT OPINION

From pivotal trials, the efficacy and tolerability of atogepant in episodic migraine prophylaxis seem comparable to those of CGRP monoclonal antibodies, even if comparative studies have not been conducted. To date, limited information is available on atogepant, including the optimal dose and duration of therapy; hence, it is difficult to establish whether it could be a first-line drug for migraine prophylaxis. Furthermore, it is important to evaluate if atogepant use is associated with the risk of cardiovascular and cerebrovascular events, which could result from potent and persistent blockade of vasodilation by CGRP.

Real world considerations for newly approved CGRP receptor antagonists in migraine care

INTRODUCTION

Migraine is the leading cause of years lived with disability in people under 50 . Electrophysiological phenomena at the basis of prodromal and headache attack phases and of chronification processes involve calcitonin-gene related peptide (CGRP) as a fundamental player become a game changer of migraine pharmacotherapy.Areas covered: The purpose of the present review is to retrace fundamental stages of CGRP from its discovery to the role in migraine pathogenesis and therapy to underscore the change of paradigm offered by the newly approved small molecules to antagonize CGRP receptor, the gepants. In particular, the development of this new class is gone over from the initial synthesis of C-terminus truncated CGRP antagonists to the development of the first generation of gepants ending with Zavegepant that can be considered the third generation.Expert opinion: The history of CGRP in migraine draws the successful road to follow for key signaling pathways of modulation of nociceptive facilitation by diencephalic and brainstem nuclei, including dopaminergic neurotransmission, orexin A and the large-conductance calcium-activated potassium (BK_Ca) and ATP-sensitive potassium (K_ATP) channels also investigating the potential of essential oils and the role of polymorphisms. Real-world post marketing long-term data are needed for gepants.

Serotonin receptors in epilepsy: novel treatment targets?

Despite the availability of over 30 antiseizure medications (ASMs), there is no “one size fits it all,” so there is a continuing search for novel ASMs. There are divergent data demonstrating that modulation of distinct serotonin (5‐hydroxytryptamine, 5‐HT) receptors subtypes could be beneficial in the treatment of epilepsy and its comorbidities, whereas only a few ASM, such as fenfluramine (FA), act via 5‐HT. There are 14 different 5‐HT receptor subtypes, and most epilepsy studies focus on one or a few of these subtypes, using different animal models and different ligands. We reviewed the available evidence of each 5‐HT receptor subtype using MEDLINE up to July 2021. Our search included medical subject heading (MeSH) and free terms of each “5‐HT subtype” separately and its relation to “epilepsy or seizures.” Most research underlines the antiseizure activity of 5‐HT_{1A,1D,2A,2C,3} agonism and 5‐HT₆ antagonism. Consistently, FA, which has recently been approved for the treatment of seizures in Dravet syndrome, is an agonist of 5‐HT_1D,2A,2C receptors. Even though each study focused on a distinct seizure/epilepsy type and generalization of different findings could lead to false interpretations, we believe that the available preclinical and clinical studies emphasize the role of serotonergic modulation, especially stimulation, as a promising avenue in epilepsy treatment.

Hormonal therapies in migraine management: current perspectives on patient selection and risk management

INTRODUCTION

The link between sex hormones and migraines has long been investigated but the mechanisms underlying this altered interaction are not yet fully understood. Herein, we retrace the knowledge on this association in relationship with risk of stroke.

AREAS COVERED

Estrogens fluctuations could trigger migraine attacks and exogenous estrogens intake could be a risk factor for venous thromboembolism (VTE) and stroke. At the same time, ischemic heart diseases and stroke share a common substrate with migraine and other mood disorders, depression, and anxiety.

EXPERT OPINION

The use of hormonal therapies in the context of contraception or replacement therapy must be closely evaluated in a careful risk assessment. We highlight the complex interaction of hormone/neuroinflammation pathways underlying the pathophysiology of migraine glimpsing in mood disorders a possible common denominator of link between hormonal and neuronal systems.