An outlook on the trigeminovascular mechanisms of action and side effects concerns of some potential neuropeptidergic antimigraine therapies

Understanding the Biological Relationship between Migraine and Depression

Migraine is a highly prevalent neurological disorder. Among the risk factors identified, psychiatric comorbidities, such as depression, seem to play an important role in its onset and clinical course. Patients with migraine are 2.5 times more likely to develop a depressive disorder; this risk becomes even higher in patients suffering from chronic migraine or migraine with aura. This relationship is bidirectional, since depression also predicts an earlier/worse onset of migraine, increasing the risk of migraine chronicity and, consequently, requiring a higher healthcare expenditure compared to migraine alone. All these data suggest that migraine and depression may share overlapping biological mechanisms. Herein, this review explores this topic in further detail: firstly, by introducing the common epidemiological and risk factors for this comorbidity; secondly, by focusing on providing the cumulative evidence of common biological aspects, with a particular emphasis on the serotoninergic system, neuropeptides such as calcitonin-gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide (PACAP), substance P, neuropeptide Y and orexins, sexual hormones, and the immune system; lastly, by remarking on the future challenges required to elucidate the etiopathological mechanisms of migraine and depression and providing updated information regarding new key targets for the pharmacological treatment of these clinical entities.

Adverse event profile of CGRP monoclonal antibodies: findings from the FDA adverse event reporting database

BACKGROUND

Four CGRP Monoclonal Antibodies (mAbs) have been approved for migraine prophylaxis by the Food and Drug Administration (FDA) since 2018. However, there are concerns about the safety of these four drugs for real-world use.

OBJECTIVE

To compare the adverse event profiles of four CGRP-mAbs with FAERS data.

METHODS

The study was based on records from the FAERS database. Only reports containing one of the active ingredients with CGRP-mAbs were included in this study. Disproportionality analyses including but not limited to reporting odds ratio (ROR) and information components (IC) were conducted to identify drug-AE associations.

RESULTS

In total, 58110 reports were identified for CGRP-mAbs. 80 overlapping signals were disproportionately reported. They affected a range of organs and systems, including the gastrointestinal and cardiovascular systems, skin, and hair. Additionally, the rare cardiovascular adverse events were significantly different among the four CGRP-mAbs.

CONCLUSION

We identified numerous shared underlying signals (overlapping signals) for CGRP-mAbs as suspected drugs in multiple systems and organs. The unlabeled common signals may indicate potential safety issues. In addition, the underlying safety signals varied among the four CGRP-mAbs, particularly in the cardiovascular system, and further studies are needed to confirm these associations and the potential clinical implications.

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 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.

A critical review of the neurovascular nature of migraine and the main mechanisms of action of prophylactic antimigraine medications

INTRODUCTION

Migraine involves neurovascular, functional, and anatomical alterations. Migraineurs experience an intense unilateral and pulsatile headache frequently accompanied with vomiting, nausea, photophobia, etc. Although there is no ideal preventive medication, frequency in migraine days may be partially decreased by some prophylactics, including antihypertensives, antidepressants, antiepileptics, and CGRPergic inhibitors. However, the mechanisms of action involved in antimigraine prophylaxis remain elusive.

AREAS COVERED

This review recaps some of the main neurovascular phenomena related to migraine and currently available preventive medications. Moreover, it discusses the major mechanisms of action of the recommended prophylactic medications.

EXPERT OPINION

In the last three years, migraine prophylaxis has evolved from nonspecific to specific antimigraine treatments. Overall, nonspecific treatments  mainly involve neural actions, whereas specific pharmacotherapy (represented by CGRP receptor antagonists and CGRPergic monoclonal antibodies) is predominantly mediated by neurovascular mechanisms that may include, among others: (i) reduction in the cortical spreading depression (CSD)-associated events; (ii) inhibition of pain sensitization; (iii) blockade of neurogenic inflammation; and/or (iv) increase in cranial vascular tone. Accordingly, the novel antimigraine prophylaxis promises to be more effective, devoid of significant adverse effects (unlike nonspecific treatments), and more beneficial for the quality of life of migraineurs.