Other Preventive Anti-Migraine Treatments: ACE Inhibitors, ARBs, Calcium Channel Blockers, Serotonin Antagonists, and NMDA Receptor Antagonists

Voltage-gated Calcium Channels as Potential Therapeutic Targets in Migraine

Migraine is a complex and highly incapacitating neurological disorder that affects around 15% of the general population with greater incidence in women, often at the most productive age of life. Migraine physiopathology is still not fully understood, but it involves multiple mediators and events in the trigeminovascular system and the central nervous system. The identification of calcitonin gene-related peptide as a key mediator in migraine physiopathology has led to the development of effective and highly selective antimigraine therapies. However, this treatment is neither accessible nor effective for all migraine sufferers. Thus, a better understanding of migraine mechanisms and the identification of potential targets are still clearly warranted. Voltage-gated calcium channels (VGCCs) are widely distributed in the trigeminovascular system, and there is accumulating evidence of their contribution to the mechanisms associated with headache pain. Several drugs used in migraine abortive or prophylactic treatment target VGCCs, which probably contributes to their analgesic effect. This review aims to summarize the current evidence of VGGC contribution to migraine physiopathology and to discuss how current pharmacological options for migraine treatment interfere with VGGC function. PERSPECTIVE: Calcitonin gene-related peptide (CGRP) represents a major migraine mediator, but few studies have investigated the relationship between CGRP and VGCCs. CGRP release is calcium channel-dependent and VGGCs are key players in familial migraine. Further studies are needed to determine whether VGCCs are suitable molecular targets for treating migraine.

Efficacy and Safety of Galcanezumab as a Preventive Treatment for Episodic Migraine in South Korean Patients: A Post-Hoc Analysis of a Phase 3 Clinical Trial

BACKGROUND AND PURPOSE

The estimated prevalence of migraines in South Korea is 6.0%, with affected patients having unmet needs. The efficacy, safety, and tolerability of galcanezumab, a humanized monoclonal antibody, for episodic migraine (EM) prevention was evaluated in South Korean patients.

METHODS

During the double-blind period of the EVOLVE-2 phase 3 trial, patients with EM were randomized into placebo, 120 mg-galcanezumab, and 240-mg galcanezumab treatment groups. The primary endpoint was the overall mean change from baseline in the number of monthly migraine headache days during the 6-month double-blind period. We conducted a post-hoc analysis of the South Korean cohort in EVOLVE-2.

RESULTS

Among 98 South Korean patients in the intent-to-treat population, significant changes from baseline were observed in the number of monthly migraine headache days in the 240-mg galcanezumab group compared with the placebo group (-2.64, p=0.013), in the percentage of patients with ≥50% reduction in the number of monthly migraine headache days (120 mg: odds ratio=2.43, p=0.030; 240 mg: odds ratio=2.60, p=0.019), in the number of monthly migraine headache days with acute medication use (120 mg: -2.22, p=0.006; 240 mg: -2.23, p=0.005), and in the Migraine-Specific Quality-of-Life Role Function-Restrictive (120 mg: 8.34, p=0.040). Numerical improvements from baseline were observed relative to the placebo group in at least one galcanezumab group for: the percentage of patients with ≥75% reduction in the number of monthly migraine headache days functional impairment, and disease severity. The most common treatment-emergent adverse event in the combined galcanezumab group was injection site reaction, which led to treatment discontinuation for one patient.

CONCLUSIONS

Galcanezumab treatment demonstrated efficacy and a favorable safety and tolerability profile in South Korean patients with EM.

Future targets for migraine treatment beyond CGRP

BACKGROUND

Migraine is a disabling and chronic neurovascular headache disorder. Trigeminal vascular activation and release of calcitonin gene-related peptide (CGRP) play a pivotal role in the pathogenesis of migraine. This knowledge has led to the development of CGRP(-receptor) therapies. Yet, a substantial proportion of patients do not respond to these treatments. Therefore, alternative targets for future therapies are warranted. The current narrative review provides a comprehensive overview of the pathophysiological role of these possible non-CGRP targets in migraine.

FINDINGS

We covered targets of the metabotropic receptors (pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal peptide (VIP), amylin, and adrenomedullin), intracellular targets (nitric oxide (NO), phosphodiesterase-3 (PDE3) and -5 (PDE5)), and ion channels (potassium, calcium, transient receptor potential (TRP), and acid-sensing ion channels (ASIC)). The majority of non-CGRP targets were able to induce migraine-like attacks, except for (i) calcium channels, as it is not yet possible to directly target channels to elucidate their precise involvement in migraine; (ii) TRP channels, activation of which can induce non-migraine headache; and (iii) ASICs, as their potential in inducing migraine attacks has not been investigated thus far. Drugs that target its receptors exist for PACAP, NO, and the potassium, TRP, and ASIC channels. No selective drugs exist for the other targets, however, some existing (migraine) treatments appear to indirectly antagonize responses to amylin, adrenomedullin, and calcium channels. Drugs against PACAP, NO, potassium channels, TRP channels, and only a PAC₁ antibody have been tested for migraine treatment, albeit with ambiguous results.

CONCLUSION

While current research on these non-CGRP drug targets has not yet led to the development of efficacious therapies, human provocation studies using these targets have provided valuable insight into underlying mechanisms of migraine headaches and auras. Further studies are needed on these alternative therapies in non-responders of CGRP(-receptor) targeted therapies with the ultimate aim to pave the way towards a headache-free future for all migraine patients.

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.

Consensus of the Brazilian Headache Society (SBCe) for prophylactic treatment of episodic migraine: part II

BACKGROUND

Migraine affects 1 billion people worldwide and > 30 million Brazilians; besides, it is an underdiagnosed and undertreated disorder.

OBJECTIVE

The need to disseminate knowledge about the prophylactic treatment of migraine is known, so the Brazilian Headache Society (SBCe, in the Portuguese acronym) appointed a committee of authors with the objective of establishing a consensus with recommendations on the prophylactic treatment of episodic migraine based on articles from the world literature as well as from personal experience.

METHODS

Meetings were held entirely online, with the participation of 12 groups that reviewed and wrote about the pharmacological categories of drugs and, at the end, met to read and finish the document. The drug classes studied in part II of this Consensus were: antihypertensives, selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, calcium channel blockers, other drugs, and rational polytherapy.

RESULTS

From this list of drugs, only candesartan has been established as effective in controlling episodic migraine. Flunarizine, venlafaxine, duloxetine, and pizotifen were defined as likely to be effective, while lisinopril, enalapril, escitalopram, fluvoxamine, quetiapine, atorvastatin, simvastatin, cyproheptadine, and melatonin were possibly effective in prophylaxis of the disease.

CONCLUSIONS

Despite an effort by the scientific community to find really effective drugs in the treatment of migraine, given the large number of drugs tested for this purpose, we still have few therapeutic options.

Effectiveness and Safety of Memantine for Headache: A Meta-analysis of Randomized Controlled Studies

OBJECTIVE

The effectiveness and safety of memantine for headache are elusive, and this meta-analysis aimed to explore the influence of memantine versus placebo for headache.

METHODS

We have searched PubMed, Embase, Web of science, EBSCO, and Cochrane library databases through May 2021 and included randomized controlled trials reporting memantine versus placebo for headache patients. This meta-analysis is performed using the random-effects model.

RESULTS

Our meta-analysis included 4 randomized controlled trials and 229 patients. Compared with control group for headache, memantine treatment could substantially reduce headache days (mean difference [MD] = -3.10; 95% confidence interval [CI] = -5.46 to -0.75; P = 0.01), pain intensity (MD, -0.43; 95% CI, -0.85 to -0.01; P = 0.04), monthly attack frequency (MD, -2.14; 95% CI, -2.83 to -1.46; P < 0.00001), and Migraine Disability Assessment Test (MD, -5.63; 95% CI, -6.46 to -4.79; P < 0.00001) but revealed no significant influence on days for acute pain medications, adverse events, or nausea/vomiting.

CONCLUSIONS

Memantine treatment is effective and safe to treat headache.

Role of memantine in the prophylactic treatment of episodic migraine: A systematic review

OBJECTIVE

The purpose of this systematic review is to assess the efficacy and safety of memantine for the prophylactic treatment of episodic migraine.

BACKGROUND

Migraine is a prevalent chronic disease with significant costs to the health care system. Although various prophylactic treatment options are available, these medications have limitations based on efficacy, potential side effects, and patient preference. Memantine is an N-methyl-d-aspartate receptor antagonist used in dementia treatment that may have potential benefit for migraine prophylaxis.

METHODS

A systematic search of PubMed, Embase, and CENTRAL databases was conducted to identify relevant published studies through December 2020 using the search terms: migraine disorders, migraine, headache disorders, or headache and memantine. Studies selected for the systematic review included prospective, interventional designs and evaluated memantine for prophylaxis of migraine. Animal studies, case reports, abstracts, review articles, protocols without results, and studies not written in English were excluded. Data were extracted using a standardized systematic process and included author, publication date, study design, sample size, patient characteristics, treatment regimen, clinical efficacy outcomes, and adverse drug effects.

RESULTS

Four articles were identified for inclusion representing two prospective open-label studies and two randomized, double-blind trials, evaluating 183 patients on memantine overall. A reduction in number of migraine days and headache severity were shown in all four studies in the participants treated with memantine. The most common adverse effects included somnolence, sedation, and nausea, none of which were severe.

CONCLUSION

The studies in this review establish that memantine has the potential for use as a treatment option for episodic migraine. Additional long-term studies using an active comparator would be useful to further elucidate its role.

Preventive Oral Treatment of Episodic Migraine: An Overview

Background

Migraine is a common primary headache disorder and Episodic migraine is characterized by the occurrence of up to 14 headache days in a month. The preventive treatment of migraine is useful in patients with frequent migraine attacks, impaired activities of daily living, failure of acute pain management, disabling aura and limitations in the use of acute treatment. It is aimed at reducing headache frequency and intensity, improve response to acute treatment of migraine and improve the quality of life.

Aim

To analyze the evidence for the efficacy and tolerability of preventive oral drugs used in the management of episodic migraine.

Methods

A narrative review of the references were reviewed by searching the literature for the articles published in PubMed in English language using all the following MeSH keywords "preventive treatment", "preventive oral treatment", AND "episodic migraine", "migraine".

Results

Out of articles identified in the search, 38 articles were reviewed for evidence and summarized. The various oral drugs used in the prevention of episodic migraine are antihypertensives (beta-blockers, calcium channel blockers and Angiotensin-converting enzyme inhibitors/Angiotensin receptor blockers), antidepressants (tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors), antiepileptic drugs (valproic acid, topiramate, lamotrigine) and other miscellaneous agents. HURT questionnaire and HALT 30 index are useful in assessing response to treatment in the follow up of migraine patients.

Conclusion

An appropriately chosen oral drug is useful in the preventive treatment of episodic migraine. In patients, who fail to respond to the preventive treatment, it is essential to review the diagnosis of migraine, titrate the dosage and duration of preventive treatment and ensure patient compliance. In those patients who fail to respond to monotherapy, polytherapy is a useful option to be considered.

Preventive Migraine Treatment

PURPOSE OF REVIEW

This article provides an overview of preventive interventions for migraine, including when to start and how to choose a treatment, pharmacologic options (both older oral treatments and new monoclonal antibodies to calcitonin gene-related peptide [CGRP] or its receptor), nonpharmacologic treatment such as neuromodulation, and preventive treatment of refractory migraine.

RECENT FINDINGS

The migraine preventive treatment landscape has been transformed by the development of monoclonal antibodies targeting CGRP or its receptor. These treatments, which are given subcutaneously or intravenously monthly or quarterly, have high efficacy and were well tolerated in clinical trials. Emerging real-world studies have found higher rates of adverse events than were seen in clinical trials. They are currently recommended for use if two traditional preventive therapies have proven inadequate. Since the commonly cited 2012 American Headache Society/American Academy of Neurology migraine prevention guidelines were released, clinical trials supporting the preventive use of lisinopril, candesartan, and memantine have been published. Neuromodulation devices, including external trigeminal nerve stimulation and single-pulse transcranial magnetic stimulation devices, have modest evidence to support preventive use. The American Headache Society/American Academy of Neurology guidelines for the preventive treatment of migraine are currently being updated. A new class of oral CGRP receptor antagonists (gepants) is being tested for migraine prevention.

SUMMARY

Successful preventive treatment of migraine reduces disease burden and improves quality of life. Many pharmacologic and nonpharmacologic treatment options are available for the prevention of migraine, including newer therapies aimed at the CGRP pathway as well as older treatments with good evidence for efficacy. Multiple treatment trials may be required to find the best preventive for an individual patient.

The Efficacy of Memantine for the Treatment of Migraine: A Meta-Analysis of Randomized Controlled Studies

INTRODUCTION

The efficacy of memantine for migraine remains controversial. We conduct a systematic review and meta-analysis to explore the influence of memantine versus placebo on treatment in migraine patients.

METHODS

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through February 2020 for randomized controlled trials assessing the effect of memantine versus placebo on treatment efficacy in migraine patients. This meta-analysis is performed using the random-effect model.

RESULTS

Three randomized controlled trials are included in the meta-analysis. Overall, compared with control group in migraine patients, memantine treatment is associated with substantially reduced monthly attack frequency (mean difference [MD], -2.14; 95% confidence interval [CI], -2.83 to -1.46; P < 0.00001), number of migraine days (MD, -4.17; 95% CI, -6.40 to -1.93; P = 0.0003) and Migraine Disability Assessment (MD, -5.63; 95% CI, -6.46 to -4.79; P < 0.00001), but demonstrates no obvious influence on acute pain medications (MD, -1.23; 95% CI, -4.63 to 2.17; P = 0.48).

CONCLUSIONS

Memantine treatment may benefit to the control of migraine.

Migraine: Calcium Channels and Glia

Migraine is a common neurological disease that affects about 11% of the adult population. The disease is divided into two main clinical subtypes: migraine with aura and migraine without aura. According to the neurovascular theory of migraine, the activation of the trigeminovascular system (TGVS) and the release of numerous neuropeptides, including calcitonin gene-related peptide (CGRP) are involved in headache pathogenesis. TGVS can be activated by cortical spreading depression (CSD), a phenomenon responsible for the aura. The mechanism of CSD, stemming in part from aberrant interactions between neurons and glia have been studied in models of familial hemiplegic migraine (FHM), a rare monogenic form of migraine with aura. The present review focuses on those interactions, especially as seen in FHM type 1, a variant of the disease caused by a mutation in CACNA1A, which encodes the α1A subunit of the P/Q-type voltage-gated calcium channel.

The renin angiotensin aldosterone system and COVID-19

The ongoing pandemic has stimulated study of the Renin Angiotensin Aldosterone System (RAAS), and how it can be manipulated to treat COVID-19. Studies are examining whether drugs that act on the RAAS system might be useful to treat COVID-19. COVID-19 and the RAAS are closely linked both in infection and in possible post-infection inflammatory cascades. We detail the Physiology and Pharmacology of the RAAS including the effects of aldosterone and atrial natriuretic peptide. It is appropriate that the theoretical benefits of modulation of the RAAS should be considered based on available knowledge of the complexity of the system. In this short review we have tried to explain the actions of the angiotensin family of peptides and produce a relatively simple model and diagrammatic summary of the RAAS and the possible sites of intervention.

A Systematic Review and Meta-analysis of the Therapeutic Effect of Acupuncture on Migraine

Background: Migraine is an intractable headache disorder, manifesting as periodic attacks. It is highly burdensome for patients and society. Acupuncture treatment can be beneficial as a supplementary and preventive therapy for migraine. Objectives: This systematic review and meta-analysis aimed to investigate the efficacy and safety of acupuncture for migraine, and to examine transcranial doppler changes after acupuncture. Methods: Reports, conference, and academic papers published before March 15, 2019 in databases including PubMed, Cochrane library, Embase, China National Knowledge Infrastructure, WANFANG Database, Chinese journal of Science and Technology, and China Biomedical were searched. Randomized controlled trials (RCTs) involving acupuncture, sham acupuncture, and medication in migraine were included. The Cochrane Collaboration software, RevMan 5.3, was used for data processing and migration risk analysis. Results: Twenty-eight RCTs were included. 15 RCTs included medication only, 10 RCTs included sham acupuncture only, and 3 RCTs included both. The study included 2874 patients, split into 3 groups: acupuncture treatment group (n = 1396), medication control group (n = 865), and sham acupuncture control group (n = 613). The results showed that treatment was more effective in the acupuncture group than in the sham acupuncture group (MD = 1.88, 95% CI [1.61, 2.20], P < 0.00001) and medication group (MD = 1.16, 95% CI [1.12, 1.21], P < 0.00001). Improvement in visual analog scale (VAS) score was greater in the acupuncture group than in the sham acupuncture group (MD = -1.00, 95% CI [-1.27,-0.46], P < 0.00001; MD = -0.59, 95% CI [-0.81,-0.38], P < 0.00001), and their adverse reaction rate was lower than that of the medication group (RR = 0.16, 95% CI [0.05, 0.52], P = 0.002). The improvement of intracranial blood flow velocity by acupuncture is better than that by medication, but the heterogeneity makes the result unreliable. Conclusions: Acupuncture reduced the frequency of migraine attacks, lowered VAS scores, and increased therapeutic efficiency compared with sham acupuncture. Compared with medication, acupuncture showed higher effectiveness with less adverse reactions and improved intracranial blood circulation. However, owing to inter-study heterogeneity, a prospective, multicenter RCT with a large sample is required to verify these results.

Integrating Pathophysiology in Migraine: Role of the Gut Microbiome and Melatonin

BACKGROUND

The pathoetiology and pathophysiology of migraine are widely accepted as unknown.

METHODS

The current article reviews the wide array of data associated with the biological underpinnings of migraine and provides a framework that integrates previously disparate bodies of data.

RESULTS

The importance of alterations in stress- and pro-inflammatory cytokine- induced gut dysbiosis, especially butyrate production, are highlighted. This is linked to a decrease in the availability of melatonin, and a relative increase in the N-acetylserotonin/melatonin ratio, which has consequences for the heightened glutamatergic excitatory transmission in migraine. It is proposed that suboptimal mitochondria functioning and metabolic regulation drive alterations in astrocytes and satellite glial cells that underpin the vasoregulatory and nociceptive changes in migraine.

CONCLUSION

This provides a framework not only for classical migraine associated factors, such as calcitonin-gene related peptide and serotonin, but also for wider factors in the developmental pathoetiology of migraine. A number of future research and treatment implications arise, including the clinical utilization of sodium butyrate and melatonin in the management of migraine.