Gastric stasis in migraineurs: etiology, characteristics, and clinical and therapeutic implications

Difference in Cyclic Versus Non-cyclic Symptom Patterns in Patients with the Symptoms of Gastroparesis Undergoing Bioelectric Therapy

INTRODUCTION

Patients with gastroparesis (Gp) have symptoms with or without a cyclic pattern. This retrospective study evaluates differences in cyclic vs. non-cyclic symptoms of Gp by analyzing mucosal electrogastrogram (mEG), familial dysautonomias, and response to gastric stimulation.

METHODS

37 patients with drug refractory Gp, 7 male and 30 female, with a mean age of 41.4 years, were studied. 18 had diabetes mellitus, 25 had cyclic (Cyc), and 12 had a non-cyclic (NoCyc) pattern of symptoms. Patients underwent temporary mucosal gastric stimulator (tGES) placement, which was done as a trial before permanent stimulator (GES) placement. Electrogastrogram (EGG) by mucosal (mEG) measures, including frequency, amplitude, and frequency-amplitude ratio (FAR), were pre- and post-tGES. Patients' history of personal and familial dysautonomias, quality of life, and symptom scores were recorded. Baseline vs. follow-ups were compared by paired t tests and McNemar's tests. T tests contrasted symptom scores, gastric emptying tests (GET), and mEG measures, while chi-squared tests deciphered comorbidity differences between two groups and univariate and multivariate analyses.

RESULTS

There were significantly more patients with diabetes in the Cyc group vs. the NoCyc group. Using a 1 point in symptom outcome, 18 patients did not improve and 19 did improve with tGES. Using univariable analysis, with the cyclic pattern as a predictor, patients exhibiting a cyclic pattern had an odds ratio of 0.22 (95% CI 0.05-0.81, p = 0.054) for achieving an improvement of at least one unit in vomiting at follow-up from baseline. The mucosal electrogastrogram frequency to amplitude ratio (FAR) for the "not Improved" group was 19.6 [3.5, 33.6], whereas, for the "Improved" group, it was 54.3 [25.6, 72.5] with a p-value of 0.049. For multivariate logistic regression, accounting for sex and age squared, patients exhibiting a cyclic pattern had an adjusted odds ratio (OR) of 0.16 (95% CI 0.03-0.81, p = 0.027) for achieving an improvement of at least one unit in vomiting at follow-up from baseline. The two groups had no significant differences in the personal or inherited history of investigated familial patterns.

CONCLUSION

This study shows differences in Gp patients with Cyc vs. NoCyc symptoms in several areas. Larger studies are needed to elicit further differences between the two groups about cycles of symptoms, EGG, findings, familial patterns, and response to mucosal GES.

The kynurenine pathway of tryptophan metabolism in abdominal migraine in children - A therapeutic potential?

BACKGROUND

Abdominal migraine (AM) is a clinical diagnosis specified by Rome IV and ICHD III as a functional gastrointestinal disease (FGID) and a migraine associated syndrome, respectively. Abdominal migraine in childhood and adolescence may continue with migraine headaches in adulthood. This disease is undiagnosed and undertreated, and thus far the FDA has not approved any drug for AM treatment. It was shown that changes in the kynurenine (KYN) pathway of tryptophan (TRP) metabolism played an important role in the pathogenesis and treatment of FIGDs and associated mood disorders. Changes in the KYN pathway were shown in migraine and therefore it may be involved in AM pathogenesis.

FINDINGS

Abdominal migraine reflects an impairment in the communication within the gut-brain axis. Treatment approaches in AM are based on the experience of physicians, presenting personal rather than evidence-based practice, including efficacy of some drugs in adult migraine. Non-pharmacological treatment of AM is aimed at preventing or ameliorating AM triggers and is based on the STRESS mnemonic. Metabolic treatments with riboflavin and coenzyme Q10 were effective in several cases of pediatric migraine, but in general, results on metabolic treatment in migraine in children are scarce and nonconclusive. Modulations within the KYN pathway of TRP metabolism induced by changes in TRP content in the diet, may ameliorate FGIDs and support their pharmacological treatment. Pharmacological manipulations of brain KYNs in animals have brought promising results for clinical applications. Obese children show a higher headache prevalence and may be especially predisposed to AM, and KYN metabolites showed an alternated distribution in obese individuals as compared with their normal-weight counterparts.

CONCLUSIONS

In conclusion, controlled placebo-based clinical trials with dietary manipulation to adjust the amount of the product of the KYN pathway of TRP metabolism are justified in children and adolescents with AM, especially those with coexisting obesity. Further preclinical studies are needed to establish details of these trials.

Statistically Optimized Polymeric Buccal Films of Eletriptan Hydrobromide and Itopride Hydrochloride: An In Vivo Pharmacokinetic Study

A migraine is a condition of severe headaches, causing a disturbance in the daily life of the patient. The current studies were designed to develop immediate-release polymeric buccal films of Eletriptan Hydrobromide (EHBR) and Itopride Hydrochloride (ITHC) to improve their bioavailability and, hence, improve compliance with the patients of migraines and its associated symptoms. The prepared films were evaluated for various in vitro parameters, including surface morphology, mechanical strength, disintegration test (DT), total dissolving time (TDT), drug release and drug permeation, etc., and in vivo pharmacokinetic parameters, such as area under curve (AUC), mean residence time (MRT), half-life (t1/2), time to reach maximum concentration (Tmax), and time to reach maximum concentration (Cmax). The outcomes have indicated the successful preparation of the films, as SEM has confirmed the smooth surface and uniform distribution of drugs throughout the polymer matrix. The films were found to be mechanically stable as indicated by folding endurance studies. Furthermore, the optimized formulations showed a DT of 13 ± 1 s and TDT of 42.6 ± 0.75 s, indicating prompt disintegration as well as the dissolution of the films. Albino rabbits were used for in vivo pharmacokinetics, and the outcomes were evident of improved pharmacokinetics. The drug was found to rapidly permeate across the buccal mucosa, leading to increased bioavailability of the drug: Cmax of 130 and 119 ng/mL of ITHC and EHBR, respectively, as compared to 96 (ITHC) and 90 ng/mL (EHBR) of oral solution. The conclusion can be drawn that possible reasons for the enhanced bioavailability could be the increased surface area in the form of buccal films, its rapid disintegration, and faster dissolution, which led toward the rapid absorption of the drug into the blood stream.

The Pharmacokinetics of Drugs Delivered to the Upper Nasal Space

Pharmacokinetics (PK) includes how a drug is absorbed, distributed, metabolized and eliminated. The compartment providing this information is usually the plasma. This is as close to the tissue of interest that we can get, although biopsies may be obtained to give "tissue levels" of drugs. Ultimately, the goal of PK is to understand how long the drug is actually engaged with the target in the tissue of interest after a dose has been administered. Most drugs at some point in their development will have been administered intravenously (IV), which acts as the standard for 100% bioavailability. By comparing various routes of administration to IV, the percentage of drug delivered to the plasma, on a dose-normalized basis, can be calculated and is referred to as the "absolute bioavailability". As pharmacology has advanced and more drugs have become available, many older products have been reformulated to be given by routes other than those originally intended (often oral). As the drawbacks of oral (or IV) administration have become better appreciated, non-oral, non-IV formulations and methods of administration have become more popular. Nasal administration is one route that has historically been overlooked as an alternative to oral administration-particularly for products needing rapid and non-invasive access to the target tissue-mostly via the blood stream. But attention is now focused on nasal administration for direct access to the brain, as that has the potential to bypass the blood-brain-barrier (BBB), which not even IV administration can always achieve. Assessing PK for these drugs targeting the brain may require serial sampling of the cerebrospinal fluid (CSF), making PK assessments of CNS drugs more invasive and complex, but still possible in future product development. However, we are now seeing more drugs reformulated for nasal delivery to gain faster systemic levels than oral administration (especially in patients with known or suspected gastrointestinal dysmotility), while avoiding the use of needles. For example, in recent years several different formulations and delivery methods for an old drug, dihydroergotamine (DHE), have been developed and these show very different characteristics, suggesting that delivery to different parts of the nose may have very different PK profiles. This review summarizes the systemic PK of different nasal DHE options that have been, or are being, developed and suggests that delivery of drugs to the upper nasal space (UNS) may represent an optimal target. Further research is required to ascertain if this route could also be utilized for direct administration to the CNS (as an attractive alternative to intrathecal delivery) via the olfactory or trigeminal nerves-but already preclinical data (and some human data) suggest this is entirely possible.

Gastroparesis and Gastroparesis Syndromes as Neuromuscular Disorders

Gastroparesis syndromes (GpS) are a spectrum of disorders presenting with characteristic symptoms increasingly recognized as being gastrointestinal (GI) neuromuscular disorders (NMDs). This review focuses on GpS as a manifestation of neurologic disorders of GI NMD. GpS can be associated with systemic abnormalities, including inflammatory, metabolic, and serologic disorders, as well as autoimmune antibodies via nerve and muscle targets in the GI tract, which can be treated with immunotherapy, such as intravenous immunoglobulin. GpS are associated with autonomic (ANS) and enteric (ENS) dysfunction. Disorders of ANS may interact with the ENS and are the subject of continued investigation. ENS disorders have been recognized for a century but have only recently begun to be fully quantified. Anatomic structural changes in the GI tract are increasingly recognized in GpS. Detailed descriptions of anatomic changes in GpS, and their correlation with physiologic findings, have opened a new era of investigation. The management of GpS, when viewed as GI NMD, has shifted the paradigms of both diagnosis and treatment. This article concludes with current approaches to GpS directed at underlying neuromuscular pathology.

The Upper Nasal Space: Option for Systemic Drug Delivery, Mucosal Vaccines and "Nose-to-Brain"

Sino-nasal disease is appropriately treated with topical treatment, where the nasal mucosa acts as a barrier to systemic absorption. Non-invasive nasal delivery of drugs has produced some small molecule products with good bioavailability. With the recent COVID pandemic and the need for nasal mucosal immunity becoming more appreciated, more interest has become focused on the nasal cavity for vaccine delivery. In parallel, it has been recognized that drug delivery to different parts of the nose can have different results and for "nose-to-brain" delivery, deposition on the olfactory epithelium of the upper nasal space is desirable. Here the non-motile cilia and reduced mucociliary clearance lead to longer residence time that permits enhanced absorption, either into the systemic circulation or directly into the CNS. Many of the developments in nasal delivery have been to add bioadhesives and absorption/permeation enhancers, creating more complicated formulations and development pathways, but other projects have shown that the delivery device itself may allow more differential targeting of the upper nasal space without these additions and that could allow faster and more efficient programs to bring a wider range of drugs-and vaccines-to market.

[The state of the oropharyngeal microbiome in patients with migraine]

OBJECTIVE

To determine a role of changes in the oropharyngeal microbiome in the development and clinical manifestations of migraine.

MATERIAL AND METHODS

Seventy patients with migraine, aged 21-56 years, and 15 healthy subjects matched for age and sex were examined using headache diary, MIDAS and VAS, the Gastrointestinal Symptom Rating Scale (GSRS), microbiological smear examination from the mucous membrane of the posterior wall of the oropharynx with evaluation by the method of mass spectrometry of microbial markers (MSMM) with determination of 57 microorganisms.

RESULTS

The following changes in the oropharynx of individuals with migraine compared with the group of healthy individuals (control group) were found: a) a significant increase in the content of markers of resident (conditionally pathogenic) microorganisms characteristic of chronic diseases of the upper respiratory tract (strepto- and staphylococci); b) the appearance of markers of transient microorganisms normally absent, characteristic of the intestinal microflora (clostridia, gram-negative rods, enterobacteria, anaerobes); c) the appearance of viral markers of cytomegaloviruses, Herpes group, Epstein-Barr; d) a significant decrease in the content of bifidobacteria and lactobacilli). All people with migraine had a history or were found on examination to have chronic diseases of the upper respiratory tract (sinusitis in 48%, pharyngitis in 43%, tonsillitis in 25% of people), and gastrointestinal diseases. Dyspepsia was the most frequent and pronounced of the gastrointestinal syndromes on the GSRS in people with migraine (87%). This corresponds to the data on the extremely frequent occurrence of IBS (70% of patients) and other gastrointestinal pathology obtained from the patient history.

CONCLUSION

In our work, the microbiota of the oropharynx in patients with migraine was studied for the first time using a new MSMM method. Disturbance of the oropharyngeal microbiome compared to the norm was detected in 100% of people with migraine. The changes characteristic of most patients included a significant decrease in the content of normal flora, an increase in the concentration of conditionally pathogenic microorganisms and the appearance of pathogenic microflora characteristic of chronic diseases of the upper respiratory tract and gastrointestinal tract, which may indicate their role in the pathogenesis of migraine.

Migraine and Gastroparesis

PURPOSEOF REVIEW

Migraine is a chronic and disabling disease affecting a significant proportion of the world's population. There is evidence that gastroparesis, a gastrointestinal (GI) dysmotility disorder in which transit of gastric contents is delayed, can occur in the setting of migraine. This article aims to review recent literature on overlap in the pathophysiology and clinical manifestations of migraine and gastroparesis and highlight management considerations when these disorders coexist.

RECENT FINDINGS

There has been increasing recognition of the importance of the connection between the GI tract and the brain, and mounting evidence for the overlap in the pathophysiology of migraine and gastroparesis specifically. There exists a complex interplay between the central, autonomic, and enteric nervous systems. Studies show that gastroparesis may be present during and between acute migraine attacks necessitating modification of management to optimize outcomes. Gastric dysmotility in the setting of migraine can impact absorption of oral migraine medications and alternate formulations should be considered for some patients. Noninvasive vagus nerve stimulation has been FDA cleared for migraine treatment and is also being studied in gastroparesis. Dysfunction of the autonomic nervous system is a significant feature in the pathophysiology of gut motility and migraine, making treatments that modulate the vagus nerve attractive for future research.

Method development and validation for simultaneous determination of Eletriptan hydrobromide and Itopride hydrochloride from fast dissolving buccal films by using RP-HPLC

One of the most effective, rapid, and simple methods reversed-phase high-performance liquid chromatography (RP-HPLC) was used for simultaneous development and validation of Eletriptan hydrobromide (ELE HBR) and Itopride hydrochloride (ITP HCL) in combination. The method was validated based on the regulations of United States Pharmacopeia (USP) and International Conference on Harmonization (ICH) guidelines. Separation of both drugs was achieved within approximately 5 min by using a mobile phase made up of a 70:30 ratio of phosphate buffer and acetonitrile having a flow rate of 1 mL min−1. Furthermore, a comprehensive study was conducted on precision, accuracy, linearity, inter-day, intra-day studies, an assay of formulated films, and stability studies of combined prepared film. Co-efficient of correlation ranged between 0.9993, and 0.9965 for ELE HBR and ITP HCL respectively. The accuracy of the developed method was accurate as drug recoveries in both cases of ITP HCL, and ELE HBR falls between (99.87, 99.96, and 99.84%) to (99.81, 99.12, and 98.44%) respectively having a concentration range of solutions between 10, 30 and 50 μg mL−1 dilution. Films developed by using both drugs in combination were then validated for assay studies, and it was found that substantial results of 99.05%, and 99.87% were found in the case of ITP HCL and ELE HBR respectively. The stability of the solution and mobile phase showed the method's accuracy as the results were 97% for ITP HCL and 99% for ELE HBR. The proposed method developed for simultaneous determination of ITP HCL and ELE HBR was developed and validation and no interaction of any excipient were found.

Self-administered subcutaneous diclofenac sodium in acute migraine attack: A randomized, double-blind, placebo-controlled dose-finding pilot study

BACKGROUND

A novel formulation of diclofenac, complexed with hydroxypropyl-β-cyclodextrin (HPβCD) as a solubility enhancer, in a prefilled syringe for self-administered subcutaneous injection may overcome the limitations of acute migraine treatments administered by oral, rectal, intramuscular, or intravenous routes.

METHODS

This multicentre, phase 2, double-blind, randomized, placebo-controlled, dose-finding pilot study evaluated the efficacy, safety and tolerability of three different doses (25/50/75 mg/1 mL) of subcutaneous diclofenac sodium in the treatment of an acute migraine attack in 122 subjects. The primary efficacy endpoint was the percentage of patients pain-free at 2 hours after the study drug injection.

RESULTS

A significantly higher percentage of patients in the 50 mg diclofenac group 14 (46.7%) were pain-free at 2 hours when compared with placebo: 9 (29.0%) (p = 0.01). The 50 mg dose proved superior to placebo also in the majority of the secondary endpoints. The overall global impression favoured diclofenac vs placebo. There were no adverse events leading to study withdrawal. The majority of treatment-emergent adverse events were mild.

CONCLUSIONS

The 50 mg dose of this novel formulation of diclofenac represents a valuable self-administered option for the acute treatment of migraine attacks.Trial registration: EudraCT Registration No. 2017-004828-29.

Headache as a Neurologic Manifestation of Systemic Disease

Purpose of Review

Recent Findings

Summary

Was it something I ate? Understanding the bidirectional interaction of migraine and appetite neural circuits

Migraine attacks can involve changes of appetite: while fasting or skipping meals are often reported triggers in susceptible individuals, hunger or food craving are reported in the premonitory phase. Over the last decade, there has been a growing interest and recognition of the importance of studying these overlapping fields of neuroscience, which has led to novel findings. The data suggest additional studies are needed to unravel key neurobiological mechanisms underlying the bidirectional interaction between migraine and appetite. Herein, we review information about the metabolic migraine phenotype and explore migraine therapeutic targets that have a strong input on appetite neuronal circuits, including the calcitonin gene-related peptide (CGRP), the pituitary adenylate cyclase-activating polypeptide (PACAP) and the orexins. Furthermore, we focus on potential therapeutic peptide targets that are involved in regulation of feeding and play a role in migraine pathophysiology, such as neuropeptide Y, insulin, glucagon and leptin. We then examine the orexigenic - anorexigenic circuit feedback loop and explore glucose metabolism disturbances. Additionally, it is proposed a different perspective on the most reported feeding-related trigger - skipping meals - as well as a link between contrasting feeding behaviors (skipping meals vs food craving). Our review aims to increase awareness of migraine through the lens of appetite neurobiology in order to improve our understanding of the earlier phase of migraine, encourage better studies and cross-disciplinary collaborations, and provide novel migraine-specific therapeutic opportunities.

SCFA Treatment Alleviates Pathological Signs of Migraine and Related Intestinal Alterations in a Mouse Model of NTG-Induced Migraine

Background: There is a growing realization that the gut–brain axis signaling is critical for maintaining the health and homeostasis of the Central Nervous System (CNS) and the intestinal environment. The role of Short-Chain Fatty Acids (SCFAs), such as Sodium Propionate (SP) and Sodium Butyrate (SB), has been reported to counteract inflammation activation in the central and Enteric Nervous System (ENS). Methods: In this study, we evaluated the role of the SCFAs in regulating the pathophysiology of migraine and correlated dysregulations in the gut environment in a mouse model of Nitroglycerine (NTG)-induced migraine. Results: We showed that, following behavioral tests evaluating pain and photophobia, the SP and SB treatments attenuated pain attacks provoked by NTG. Moreover, treatments with both SCFAs reduced histological damage in the trigeminal nerve nucleus and decreased the expression of proinflammatory mediators. Ileum evaluation following NTG injection reported that SCFA treatments importantly restored intestinal mucosa alterations, as well as the release of neurotransmitters in the ENS. Conclusions: Taken together, these results provide evidence that SCFAs exert powerful effects, preventing inflammation through the gut–brain axis, suggesting a new insight into the potential application of SCFAs as novel supportive therapies for migraine and correlated intestinal alterations.

Kynurenine Pathway of Tryptophan Metabolism in Migraine and Functional Gastrointestinal Disorders

Migraine, the leading cause of disability in the population aged below 50, is associated with functional gastrointestinal (GI) disorders (FGIDs) such as functional nausea, cyclic vomiting syndrome, and irritable bowel syndrome (IBS). Conversely, changes in intestinal GI transit may cause diarrhea or constipation and are a component of the autonomic symptoms associated with pre- and post-dorsal phases of migraine attack. These mutual relationships provoke a question on a common trigger in migraine and FGIDs. The kynurenine (l-kyn) pathway (KP) is the major route for l-tryptophan (l-Trp) metabolism and transforms l-Trp into several neuroactive compounds. Changes in KP were reported in both migraine and FGIDs. Migraine was largely untreatable, but several drugs approved lately by the FDA, including monoclonal antibodies for calcitonin gene-related peptide (CGRP) and its receptor, create a hope for a breakthrough in migraine treatment. Derivatives of l-kyn were efficient in pain relief with a mechanism including CGRP inhibition. KP products are important ligands to the aryl hydrocarbon receptor (AhR), whose activation is implicated in the pathogenesis of GI and migraine. Toll-like receptors (TLRs) may play a role in migraine and IBS pathogeneses, and KP metabolites detected downstream of TLR activation may be an IBS marker. The TLR4 signaling was observed in initiating and maintaining migraine-like behavior through myeloid differentiation primary response gene 88 (MyD88) in the mouse. The aim of this review is to justify the view that KP modulation may provide common triggers for migraine and FGIDs with the involvement of TLR, AhR, and MyD88 activation.

STOP 301: A Phase 3, open-label study of safety, tolerability, and exploratory efficacy of INP104, Precision Olfactory Delivery (POD® ) of dihydroergotamine mesylate, over 24/52 weeks in acute treatment of migraine attacks in adult patients

Objective

To report the safety, tolerability, exploratory efficacy, and patient acceptability of INP104 for the acute treatment of migraine from the Phase 3 STOP 301 trial.

Background

Dihydroergotamine (DHE) has long been used to treat migraine, but intravenous administration is invasive, frequently associated with adverse events (AEs), and not suitable for at‐home administration. INP104 is an investigational drug device that delivers DHE mesylate to the upper nasal space using a Precision Olfactory Delivery technology and was developed to overcome the shortcomings of available DHE products.

Methods

STOP 301 was an open‐label, 24‐week safety study, with a 28‐week extension period. After a 28‐day screening period where patients used their “best usual care” to treat migraine attacks, patients were given INP104 (1.45 mg) to self‐administer nasally with self‐recognized attacks. The primary objective of this study was to assess safety and tolerability, with a specific focus on nasal mucosa and olfactory function. Exploratory objectives included efficacy assessments of migraine measures and a patient acceptability questionnaire.

Results

A total of 360 patients entered the 24‐week treatment period, with 354 patients dosing at least once. INP104‐related treatment‐emergent AEs were reported by 36.7% (130/354) of patients, and 6.8% (24/354) discontinued treatment due to AEs over 24 weeks. No new safety signals were observed following delivery to the upper nasal space. Pain freedom, the most bothersome symptom freedom, and pain relief at 2 h post‐INP104 were self‐reported by 38.0% (126/332), 52.1% (173/332), and 66.3% (167/252) of patients, respectively. A low recurrence rate at 24 and 48 h was observed (7.1% [9/126] and 14.3% [18/126], respectively). Most patients found INP104 easy to use and preferred it over their current therapy.

Conclusions

INP104 has the potential to deliver rapid symptom relief, without injection, that is well tolerated and suitable for outpatient use. Results suggest INP104 may be a promising treatment for patients with migraine.

Zolmitriptan Intranasal Spanlastics for Enhanced Migraine Treatment; Formulation Parameters Optimized via Quality by Design Approach

Zolmitriptan is a potent second-generation triptan prescribed for migraine attacks. It suffers low bioavailability (40%) after oral administration due to the hepatic first-pass metabolism. Spanlastics are surfactant-based elastic vesicular drug carrier systems. This study aimed to design and optimize intranasal spanlastic formulations as an alternative approach that directly targets brain delivery, enhancing its bioavailability and avoiding the first-pass effect. The quality by design approach was applied to correlate the formulation parameters (Span 60 and Tween 80 concentrations) and critical quality attributes (entrapment efficiency (EE%) and particle size). Spanlastic formulations were designed based on response surface central composite design and prepared via an ethanol injection method. Designed formulations were characterized by EE% and particle size measurements to select the optimized formula (with a combination of small particle size and high EE%). The optimized formula was further subjected to transmission electron microscopy, zeta potential measurement and ex vivo permeation study. The optimized formulation showed a particle size of 117.5 nm and EE% of 45.65%, with a low percentage of error between the observed and predicted values. Seventy percent of zolmitriptan was permeated through the nasal membrane within 30 min, and it completely permeated within 2 h with a significantly higher steady-state flux compared to plain gel. This study introduced a successful and promising intranasal formulation suitable for further brain delivery analysis.

A link between gastrointestinal disorders and migraine: Insights into the gut-brain connection

Background

Migraine is a complex, multifaceted, and disabling headache disease that is often complicated by gastrointestinal (GI) conditions, such as gastroparesis, functional dyspepsia, and cyclic vomiting syndrome (CVS). Functional dyspepsia and CVS are part of a spectrum of disorders newly classified as disorders of gut–brain interaction (DGBI). Gastroparesis and functional dyspepsia are both associated with delayed gastric emptying, while nausea and vomiting are prominent in CVS, which are also symptoms that commonly occur with migraine attacks. Furthermore, these gastric disorders are comorbidities frequently reported by patients with migraine. While very few studies assessing GI disorders in patients with migraine have been performed, they do demonstrate a physiological link between these conditions.

Objective

To summarize the available studies supporting a link between GI comorbidities and migraine, including historical and current scientific evidence, as well as provide evidence that symptoms of GI disorders are also observed outside of migraine attacks during the interictal period. Additionally, the importance of route of administration and formulation of migraine therapies for patients with GI symptoms will be discussed.

Methods

A literature search of PubMed for articles relating to the relationship between the gut and the brain with no restriction on the publication year was performed. Studies providing scientific support for associations of gastroparesis, functional dyspepsia, and CVS with migraine and the impact these associations may have on migraine treatment were the primary focus. This is a narrative review of identified studies.

Results

Although the association between migraine and GI disorders has received very little attention in the literature, the existing evidence suggests that they may share a common etiology. In particular, the relationship between migraine, gastric motility, and vomiting has important clinical implications in the treatment of migraine, as delayed gastric emptying and vomiting may affect oral dosing compliance, and thus, the absorption and efficacy of oral migraine treatments.

Conclusions

There is evidence of a link between migraine and GI comorbidities, including those under the DGBI classification. Many patients do not find adequate relief with oral migraine therapies, which further necessitates increased recognition of GI disorders in patients with migraine by the headache community.

Consideration of Migraines Among Risk Factors for Postoperative Nausea and Vomiting

The impact of migraine on postoperative nausea and vomiting (PONV) is controversial, and few studies have focused on their relationship. Thus, we investigated the impact of migraine, among other risk factors, on PONV in a large retrospective study. We analyzed 10 years of clinical data from the Smart Clinical Data Warehouse of Hallym University Medical Center. PONV was defined as nausea or vomiting within the first 24 h after surgery. Patients diagnosed by a neurologist and with a history of triptan use before surgery were enrolled into the migraine group. We enrolled 208,029 patients aged > 18 years who underwent general anesthesia (GA), among whom 19,786 developed PONV within 24 h after GA and 1982 had migraine. Before propensity score matching, the unadjusted and fully adjusted odds ratios (ORs) for PONV in subjects with versus without migraine were 1.52 (95% confidence interval (CI), 1.34–1.72; p < 0.001) and 1.37 (95% CI, 1.21–1.56; p < 0.001), respectively. The OR for PONV in patients with migraine was also high (OR, 1.37; 95% CI, 1.13–1.66; p = 0.001) after matching. Our findings suggest that migraine is a significant risk factor for PONV.

Effect of probiotic supplementation on migraine prophylaxis: a systematic review and meta-analysis of randomized controlled trials

Objective: The prevalence of migraine is higher in patients with gastrointestinal disorders. Possible underlying mechanisms could be increased intestinal permeability and systemic inflammation. Probiotics may reduce gut permeability as well as inflammation, and therefore may improve the clinical features of migraine. This systematic review and meta-analysis aimed to evaluate the impact of probiotic supplementation on the frequency and severity of migraine attacks.Methods: A systematic review of the literature was conducted using ISI Web of Science, PubMed/Medline, Scopus, Cochrane Library, EMBASE, Google Scholar, Magiran.com and Sid.ir to identify eligible studies published up to October 2019. A meta-analysis of eligible trials was performed using the random-effects model to estimate pooled effect size.Results: Three randomized controlled trials with 179 patients (probiotic group = 94, placebo group = 85) were included. Probiotic supplementation had no significant effect on frequency (weighted mean difference (WMD) = -2.54 attacks/month, 95%CI: -5.31-0.22, p = 0.071) and severity of migraine attacks (WMD = -1.23 visual analog scale (VAS) score, 95%CI = -3.37-0.92, p = 0.262) with significant heterogeneity among the studies (I² = 98%, p < 0.001).Conclusions: A pooled analysis of available randomized controlled clinical trials showed that probiotic supplementation had no significant effect on the frequency and severity of episodic migraine attacks.

Gut-brain Axis and migraine headache: a comprehensive review

The terminology "gut-brain axis "points out a bidirectional relationship between the GI system and the central nervous system (CNS). To date, several researches have shown that migraine is associated with some gastrointestinal (GI) disorders such as Helicobacter pylori (HP) infection, irritable bowel syndrome (IBS), and celiac disease (CD). The present review article aims to discuss the direct and indirect evidence suggesting relationships between migraine and the gut-brain axis. However, the mechanisms explaining how the gut and the brain may interact in patients with migraine are not entirely clear. Studies suggest that this interaction seems to be influenced by multiple factors such as inflammatory mediators (IL-1β, IL-6, IL-8, and TNF-α), gut microbiota profile, neuropeptides and serotonin pathway, stress hormones and nutritional substances. Neuropeptides including CGRP, SP, VIP, NPY are thought to have antimicrobial impact on a variety of the gut bacterial strains and thus speculated to be involved in the bidirectional relationship between the gut and the brain. According to the current knowledge, migraine headache in patients harboring HP might be improved following the bacteria eradication. Migraineurs with long headache history and high headache frequency have a higher chance of being diagnosed with IBS. IBS and migraine share some similarities and can alter gut microflora composition and thereby may affect the gut-brain axis and inflammatory status. Migraine has been also associated with CD and the condition should be searched particularly in patients with migraine with occipital and parieto-occipital calcification at brain neuroimaging. In those patients, gluten-free diet can also be effective in reducing migraine frequency. It has also been proposed that migraine may be improved by dietary approaches with beneficial effects on gut microbiota and gut-brain axis including appropriate consumption of fiber per day, adhering to a low glycemic index diet, supplementation with vitamin D, omega-3 and probiotics as well as weight loss dietary plans for overweight and obese patients.

The Upper Nasal Space—A Novel Delivery Route Ideal for Central Nervous System Drugs

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Gastroprotective herbs for headache management in Persian medicine: A comprehensive review

The gut-brain axis is a bidirectional communication system that exists between the brain and gut. Several studies claimed that some types of headaches are associated with various gastrointestinal (GI) disorders. In Persian medicine (PM), physicians believed that gastric disturbances could stimulate headache and introduced some herbs for boosting gastric function as a therapeutic remedy for headache. Here we review the current evidence for the gastroprotective and antiheadache effects of herbs used in PM. Herbs used for their gastrotonic effects in PM were identified from selected Persian medical and pharmaceutical textbooks. PubMed, Scopus and Google Scholar were used to search for contemporary scientific evidence relating to the gastric and neurologic effects of these plants. A total of 24 plants were recorded from the selected sources included in this review, most of which belonged to the Rosaceae family. Phyllanthus emblica, Zingiber officinale, Boswellias errata, Punica granatum and Hypericum perforatum had the most recent studies related to GI disorder and headache, while current research about quince, rose, apple, hawthorn and pear was limited. Reducing Helicobacter pylori growth, gastritis, erosion of the stomach lining, hemorrhage and perforation, improving gastric mucosal resistance, antisecretary, antiulcer, antipyretic, analgesic, sedative, anxiolytic, anti-inflammatory, anticonvulsant, neuroprotective and antioxidant effects as well as improvement in memory scores were some of the gastrotonic and neuroprotective mechanisms described in the current research. These results confirmed that medicinal plants prescribed in PM may improve headache in patients through the management of GI abnormalities. However, further studies are recommended to investigate the efficacy and safety of the mentioned medicinal plants.

Calcitonin Gene-Related Peptide Modulators - The History and Renaissance of a New Migraine Drug Class

Several lines of evidence pointed to an important role for CGRP in migraine. These included the anatomic colocalization of CGRP and its receptor in sensory fibers innervating pain-producing meningeal blood vessels, its release by trigeminal stimulation, the observation of elevated CGRP in the cranial circulation during migraine with normalization concomitant with headache relief by sumatriptan, and translational studies with intravenous (IV) CGRP that evoked migraine only in migraineurs. The development of small molecule CGRP receptor antagonists (CGRP-RAs) that showed clinical antimigraine efficacy acutely and prophylactically in randomized placebo-controlled clinical trials subsequently gave definitive pharmacological proof of the importance of CGRP in migraine. More recently, CGRP target engagement imaging studies using a CGRP receptor PET ligand [¹¹ C]MK-4232 demonstrated that there was no brain CGRP receptor occupancy at clinically effective antimigraine doses of telcagepant, a prototypic CGRP-RA. Taken together, these data indicated that (1) the therapeutic site of action of the CGRP-RAs was peripheral not central; (2) that IV CGRP had most likely evoked migraine through an action at sites outside the blood-brain barrier; and (3) that migraine pain was therefore, at least in part, peripheral in origin. The evolution of CGRP migraine science gave impetus to the development of peripherally acting drugs that could modulate CGRP chronically to prevent frequent episodic and chronic migraine. Large molecule biologic antibody (mAb) approaches that are given subcutaneously to neutralize circulating CGRP peptide (fremanezumab, galcanezumab) or block CGRP receptors (erenumab) have shown consistent efficacy and tolerability in multicenter migraine prevention trials and are now approved for clinical use. Eptinezumab, a CGRP neutralizing antibody given IV, shows promise in late stage clinical development. Recently, orally administered next-generation small molecule CGRP-RAs have been shown to have safety and efficacy in acute treatment (ubrogepant and rimegepant) and prevention (atogepant) of migraine, giving additional CGRP-based therapeutic options for migraine patients.

Diagnosing and managing migraine in children and young people

This article gives an overview of migraine in children. It outlines the epidemiology of the condition and describes presentation with headache and other symptoms and linked conditions. It aims to raise awareness of the diagnosis of migraine and its impact on children and young people, their families and school life. The author also describes methods of diagnosis and management, and the importance of recognising and of avoiding medication overuse.

The effects of a multispecies probiotic supplement on inflammatory markers and episodic and chronic migraine characteristics: A randomized double-blind controlled trial

BACKGROUND

The current study was designed to assess the effect of supplementation with a 14-strain probiotic mixture on episodic and chronic migraine characteristics.

METHODS

Forty episodic and 39 chronic migraine patients who completed this randomized double-blind controlled trial received two capsules of multispecies probiotic or placebo. The migraine severity was assessed by visual analog scale (VAS). The number of abortive drugs consumed, migraine days, frequency and duration of attacks were recorded on paper-based headache diaries. Serum tumor necrosis factor alpha (TNF-α) and C- reactive protein (CRP) levels were measured at baseline and the end of the intervention.

RESULTS

After a 10-week intervention, among episodic migraineurs the mean frequency of migraine attacks significantly reduced in the probiotic group compare to the placebo group (mean change: -2.64 vs. 0.06; respectively, p < 0.001). A significant reduction was also evident in the migraine severity (mean decrease: -2.14 in the probiotic group and 0.11 in the placebo group; p < 0.001). Episodic migraineurs who received the probiotic also showed significant reduction in abortive drug usage per week (mean change: -0.72; p < 0.001) compare to baseline, while there was no significant changes within the placebo group. In chronic migraine patients, after an 8-week intervention, the mean frequency of migraine attacks significantly reduced in the probiotic compared to the placebo group (mean change: -9.67 vs. -0.22; p ≤ 0.001). In contrast to the placebo, probiotic supplementation significantly decreased the severity (mean changes: -2.69; p ≤ 0.001), duration (mean changes: -0.59; p ≤ 0.034) of attacks and the number of abortive drugs taken per day (mean changes: -1.02; p < 0.001), in chronic migraine patients. We failed to detect any significant differences in the serum levels of inflammatory markers at the end of the study either in chronic or in episodic migraineurs.

DISCUSSION

The results of this study showed that the 14-strain probiotic mixture could be an effective and beneficial supplement to improve migraine headache in both chronic and episodic migraineurs. Further research is required to confirm our observations.

Migraine, Cyclic Vomiting Syndrome, and Other Gastrointestinal Disorders

PURPOSE OF REVIEW

Cyclic vomiting syndrome (CVS) is a chronic functional gastrointestinal disorder characterized by episodic nausea and vomiting and is diagnosed using Rome IV criteria. CVS is being recognized more frequently in adults with a prevalence of 2%. It is associated with several functional disorders like autonomic dysfunction, anxiety, and depression, but the strongest association is with migraine. We will elucidate the close relationship between migraine and CVS and briefly discuss its association with other gastrointestinal disorders.

RECENT FINDINGS

We highlight similarities in pathophysiology, clinical presentation, and response to medications between CVS and migraine (tricyclic antidepressants, triptans, antiepileptics). We also discuss novel therapies like CGRP inhibitors which are effective in migraine and have potential for adaptation in patients with CVS. Using migraine as a template should enable investigators to elucidate the mechanisms underlying this disorder, develop novel therapies, and direct future research in CVS.

Pharmacokinetics of DFN-15, a Novel Oral Solution of Celecoxib, Versus Celecoxib 400-mg Capsules: A Randomized Crossover Study in Fasting Healthy Volunteers

Background

COX-2 inhibitors can be effective for acute migraine, but none is supplied in a rapidly absorbed, ready-to-use oral liquid formulation. DFN-15, a novel oral liquid formulation of celecoxib, is being developed for the acute treatment of migraine with or without aura. Clinical studies with this formulation are ongoing.

Objectives

The objectives of the present study were to compare the bioavailability of DFN-15 with that of the commercial formulation of celecoxib 400-mg oral capsules (Celebrex^®) and to determine the dose proportionality of DFN-15 in healthy fasted volunteers.

Methods

This single-dose randomized crossover study in 16 healthy fasted volunteers evaluated the pharmacokinetics and relative bioavailability of DFN-15 at doses of 120, 180, and 240 mg against the commercial formulation of celecoxib 400-mg oral capsules and determined the dose proportionality of DFN-15.

Results

The maximum observed plasma concentrations (C_max) of celecoxib after the administration of DFN-15 120, 180, and 240 mg (1062–1933 ng/ml) were higher than for the 400-mg oral capsules (611 ng/ml). The median time to peak concentration (T_max) was within 1 h for DFN-15 and 2.5 h for the oral capsules. The pharmacokinetics of DFN-15 were dose proportional from 120 to 240 mg. Partial area under the plasma concentration–time curves (AUCs) from 15 min to 2 h for DFN-15 120 mg were at least threefold higher than for the oral capsules, and the relative bioavailability of DFN-15 was approximately 140% that of the oral capsules. DFN-15 was well tolerated, with no new or unexpected adverse events.

Conclusions

Based on a faster rate of absorption and increased bioavailability, DFN-15 is being evaluated as an abortive medication for acute treatment in patients with migraine.

Clinical Implications of Associations between Headache and Gastrointestinal Disorders: A Study Using the Hallym Smart Clinical Data Warehouse

Background

The brain and gastrointestinal (GI) tract are strongly connected via neural, endocrine, and immune pathways. Previous studies suggest that headaches, especially migraines, may be associated with various GI disorders. However, upper GI endoscopy in migraineurs has shown a low prevalence of abnormal findings. Also, the majority of studies have not demonstrated an association between Helicobacter pylori (HP) infection and migraine, although a pathogenic role for HP infection in migraines has been suggested. Further knowledge concerning the relation between headaches and GI disorders is important as it may have therapeutic consequences. Thus, we sought to investigate possible associations between GI disorders and common primary headaches, such as migraines and tension-type headaches (TTH), using the Smart Clinical Data Warehouse (CDW) over a period of 10 years.

Methods

We retrospectively investigated clinical data using a clinical data analytic solution called the Smart CDW from 2006 to 2016. In patients with migraines and TTH who visited a gastroenterology center, GI disorder diagnosis, upper GI endoscopy findings, and results of HP infection were collected and compared to clinical data from controls, who had health checkups without headache. The time interval between headache diagnosis and an examination at a gastroenterology center did not exceed 1 year.

Results

Patients were age- and sex-matched and eligible cases were included in the migraine (n = 168), the TTH (n = 168), and the control group (n = 336). Among the GI disorders diagnosed by gastroenterologists, gastroesophageal reflux disorder was more prevalent in the migraine group, whereas gastric ulcers were more common in the migraine and TTH groups compared with controls (p < 0.0001). With regard to endoscopic findings, there were high numbers of erosive gastritis and chronic superficial gastritis cases in the migraine and TTH groups, respectively, and the severity of gastritis was significantly higher in patients with TTH compared with controls (p < 0.001). However, no differences were observed in the prevalence of HP infection between the groups.

Conclusion

The observed association in this study may suggest that primary headache sufferers who experience migraines or TTH are more prone to GI disorders, which may have various clinical implications. Further research concerning the etiology of the association between headaches and GI disorders is warranted.

Post Hoc Subanalysis of Two Randomized, Controlled Phase 3 Trials Evaluating Diclofenac Potassium for Oral Solution: Impact of Migraine-Associated Nausea and Prior Triptan Use on Efficacy

Objective

To determine whether baseline nausea or prior triptan treatment for migraine impact the effectiveness of diclofenac potassium for oral solution in treating acute migraine.

Background

A great deal of variability exists in patients' response to migraine medications. Migraine‐associated nausea is common and debilitating and can reduce the effectiveness of oral medications. It may cause patients to delay taking oral medications, which is known to diminish therapeutic outcomes, or to avoid taking them altogether. Gastroparesis, which may be associated with nausea, also inhibits drug absorption, resulting in lower bioavailability. Studies have shown that having nausea at the time of drug administration predicts a poorer response to triptan treatment. It is of interest to understand how effective other migraine medications are in patients with a poor response to triptans.

Methods

Data from two randomized, double‐blind, placebo controlled trials were pooled and post hoc subgroup analyses were performed in patients with and without nausea at baseline, and in patients with and without prior triptan treatment. Efficacy assessments included the percentage of patients who, at 2 hours postdosing, were headache pain‐free (2hPF, primary endpoint), without photophobia, without phonophobia, without nausea, or without a severe degree of disability. A Cochran–Mantel–Haenszel test, stratified by analysis center was used to evaluate treatment effect. Effects of nausea or prior triptan use were determined using logistic regression with factors of treatment group, analysis center, nausea or prior triptan use at time of dosing, and interaction of treatment group by nausea or prior triptan use at time of dosing.

Results

The modified intent to treat population consisted of 1272 patients, 644 on active drug and 628 on placebo. The majority of patients (85%) were female. At the time of dosing, 783 (62%) patients reported nausea with the treated attack. Prior triptan use was recorded in 570 (45%). For headache pain, nausea, photophobia, and phonophobia, patients in the active treatment group had a statistically significantly better response than those receiving placebo, regardless of whether they had nausea at baseline. In logistic regression analysis only treatment group predicted a response for these parameters with no detectable group interaction. Baseline nausea, as well as treatment group, predicted whether patients recorded severe disability at 2 hours. While patients in the active treatment group were significantly more likely to be headache pain‐free at 2 hours after dosing, whether or not they had previously been treated with triptan, more triptan‐naïve patients (30%) than triptan‐experienced patients (20%) were headache pain‐free. Interestingly, in the placebo groups, triptan‐naïve patients were also more likely to be PF (14% vs 7%). In the logistic regression analysis, treatment group predicted a headache pain response, triptan use predicted a lack of response, and there was no interaction between the two. Prior triptan use did not predict any of the other outcome measures.

Conclusions

Nausea at the time of dosing does not diminish the effectiveness of diclofenac potassium for oral solution. The rapid absorption profile may enhance the effectiveness in patients with nausea. Prior triptan use predicted poorer headache response at 2 hours postdose, suggesting the possibility of a subset of patients who are more likely to be refractory to both triptans and diclofenac. Diclofenac potassium for oral solution is effective in triptan‐naïve patients but no reliable inference can be made from this study as to about how to order treatment.

Gastrointestinal Headache; a Narrative Review

There are studies reporting primary headaches to be associated with gastrointestinal disorders, and some report resolution of headache following the treatment of the associated gastrointestinal disorder. Headache disorders are classified by The International Headache Society as primary or secondary; however, among the secondary headaches, those attributed to gastrointestinal disorders are not appreciated. Therefore, we aimed to review the literature to provide evidence for headaches, which originate from the gastrointestinal system. Gastrointestinal disorders that are reported to be associated with primary headaches include dyspepsia, gastro esophageal reflux disease (GERD), constipation, functional abdominal pain, inflammatory bowel syndrome (IBS), inflammatory bowel disorders (IBD), celiac disease, and helicobacter pylori (H. Pylori) infection. Some studies have demonstrated remission or improvement of headache following the treatment of the accompanying gastrointestinal disorders. Hypotheses explaining this association are considered to be central sensitization and parasympathetic referred pain, serotonin pathways, autonomic nervous system dysfunction, systemic vasculopathy, and food allergy. Traditional Persian physicians, namely Ebn-e-Sina (Avicenna) and Râzi (Rhazes) believed in a type of headache originating from disorders of the stomach and named it as an individual entity, the "Participatory Headache of Gastric Origin". We suggest providing a unique diagnostic entity for headaches coexisting with any gastrointestinal abnormality that are improved or cured along with the treatment of the gastrointestinal disorder.

Gastrointestinal disorders associated with migraine: A comprehensive review

Migraine is a recurrent and commonly disabling primary headache disorder that affects over 17% of women and 5%-8% of men. Migraine susceptibility is multifactorial with genetic, hormonal and environmental factors all playing an important role. The physiopathology of migraine is complex and still not fully understood. Many different neuropeptides, neurotransmitters and brain pathways have been implicated. In connection with the myriad mechanisms and pathways implicated in migraine, a variety of multisystemic comorbidities (e.g., cardiovascular, psychiatric and other neurological conditions) have been found to be closely associated with migraine. Recent reports demonstrate an increased frequency of gastrointestinal (GI) disorders in patients with migraine compared with the general population. Helicobacter pylori infection, irritable bowel syndrome, gastroparesis, hepatobiliary disorders, celiac disease and alterations in the microbiota have been linked to the occurrence of migraine. Several mechanisms involving the gut-brain axis, such as a chronic inflammatory response with inflammatory and vasoactive mediators passing to the circulatory system, intestinal microbiota modulation of the enteric immunological milieu and dysfunction of the autonomic and enteric nervous system, have been postulated to explain these associations. However, the precise mechanisms and pathways related to the gut-brain axis in migraine need to be fully elucidated. In this review, we survey the available literature linking migraine with GI disorders. We discuss the possible physiopathological mechanisms, and clinical implications as well as several future areas of interest for research.

A Randomized Trial Comparing the Pharmacokinetics, Safety, and Tolerability of DFN-02, an Intranasal Sumatriptan Spray Containing a Permeation Enhancer, With Intranasal and Subcutaneous Sumatriptan in Healthy Adults

OBJECTIVE/BACKGROUND

Intranasal sumatriptan (Imitrex^® ) may be an alternative for patients who refuse injections and cannot tolerate oral agents, but due to low bioavailability and slow absorption, the clinical utility of the currently marketed formulation is limited, highlighting an unmet need for an effective non-oral migraine medication with a rapid onset of action. To overcome the slow absorption profile associated with intranasal administration, we evaluated the impact of 1-O-n-Dodecyl-β-D-Maltopyranoside (DDM, Intravail A-3™), a permeation enhancer, on sumatriptan's pharmacokinetic profile by comparing the pharmacokinetic characteristics of two commercial sumatriptan products, 4 mg subcutaneous and 6 mg subcutaneous in healthy adults, with DFN-02 - a novel intranasal agent comprised of sumatriptan 10 mg plus 0.20% DDM. We also determined the pharmacokinetic characteristics of DDM and evaluated its safety and tolerability.

METHODS

We conducted two studies: a randomized, three-way crossover study comparing monodose and multidose devices for delivery of single doses of DFN-02 with commercially available intranasal sumatriptan 20 mg in 18 healthy, fasted adults, and an open-label, randomized, single-dose, three-way crossover bioavailability study comparing DFN-02 with 4 mg and 6 mg subcutaneous sumatriptan in 78 healthy, fasted adults. In the study comparing DFN-02 with IN sumatriptan, subjects received a single dose of DFN-02 (sumatriptan 10 mg plus DDM 0.20%) via monodose and multidose delivery systems with at least 5 days between treatments. In the comparison with SC sumatriptan, subjects received a single dose of each treatment with at least 3 days between treatments. In both studies, blood was sampled for pharmacokinetic evaluation of sumatriptan and DDM through 24 hours post-dose; safety and tolerability were monitored throughout.

RESULTS

In the comparison with commercially available intranasal sumatriptan 20 mg, DFN-02 had a more rapid absorption profile; t_max was 15 minutes for DFN-02 monodose, 10.2 minutes for DFN-02 multidose, and 2.0 hours for commercially available intranasal sumatriptan 20 mg. Compared with 4 and 6 mg subcutaneous sumatriptan, DFN-02's median t_max (10 minutes) was significantly earlier (15 minutes; P < .0001). Mean sumatriptan exposure metrics were similar for DFN-02 and 4 mg sumatriptan: AUC_0-2 : 35.12 and 44.82 ng*hour/mL, respectively; AUC_0-∞ : 60.70 and 69.21 ng*hour/mL, respectively; C_max : 51.79 and 49.07 ng/mL, respectively. With 6 mg subcutaneous sumatriptan, these exposure metrics were about 50% larger (AUC_0-2 : 67.17 ng*hour/mL; AUC_0-∞ : 103.78 ng*hour/mL; C_max : 72.75 ng/mL). Inter-subject variability of AUC_0-2 , AUC_0-∞ , and C_max was 42-58% for DFN-02, 15-22% for 4 mg subcutaneous sumatriptan, and 15-25% for 6 mg subcutaneous sumatriptan. DDM exposure was low (mean C_max : 1.63 ng/mL), t_max was 30 minutes, and it was undetectable by 4 hours. There were no serious adverse events, discontinuations due to adverse events, or remarkable findings for vital signs, physical examinations (including nasal and injection site examinations), or clinical laboratory assessments. The overall incidence of adverse events was comparable across treatments, and all treatment-related events were mild in severity. Adverse events occurring in ≥10% of subjects were dysgeusia (19%), headache (18%), nausea (15%), paresthesia (15%), and dizziness (12%).

CONCLUSIONS

In healthy subjects, DFN-02, an intranasal spray containing 10 mg sumatriptan plus DDM, had a more rapid absorption profile than commercially available intranasal sumatriptan 20 mg, and systemic exposure from a single-dose administration of DFN-02 was similar to 4 mg SC sumatriptan and two-thirds that of 6 mg SC sumatriptan. With DFN-02, plasma sumatriptan peaked 5 minutes earlier than with both subcutaneous formulations. Systemic exposure to sumatriptan was similar with DFN-02 and 4 mg subcutaneous sumatriptan; both yielded lower systemic exposure than 6 mg subcutaneous sumatriptan. Systemic exposure to DFN-02's excipient DDM was short-lived. DFN-02's safety and tolerability appear to be comparable to subcutaneous sumatriptan. Addition of a permeation enhancer improved the absorption profile compared with commercially available intranasal sumatriptan 20 mg.

Delayed absorption of many (paracetamol, aspirin, other NSAIDs and zolmitriptan) but not all (sumatriptan, rizatriptan) drugs during migraine attacks and most likely normal gastric emptying outside attacks. A review

Background In most pharmacokinetic studies, the oral absorption of drugs is impaired during migraine attacks but exceptions occur. A study on gastric emptying using gastric scintigraphy indicated that gastric stasis also occurs interictally in migraine. These studies were reviewed critically. Results In seven studies, mainly investigating NSAIDs and analgesics, the early absorption of the drugs during 112 migraine attacks was delayed. The absorption of sumatriptan is usual in therapeutic doses, and rizatriptan was normal during 131 migraine attacks. The interictal gastric stasis observed using gastric emptying scintigraphy (GES) with solids ( n = 13) could not be confirmed in a larger study ( n = 27) using the same method. Also gastric emptying measured with GES with liquids ( n = 7) and epigastric impedance ( n = 64) was normal outside migraine attacks. Conclusions and possible clinical implications Drug absorption is not generally impaired during migraine attacks. Gastric emptying is most likely normal in the majority of migraine patients outside attacks. Prokinetic and antiemetic drugs such as metoclopramide and domperidone should not be routinely combined with oral analgesics or oral triptans. If, however, nausea is severe or vomiting occurs, treatment with an antiemetic with proven efficacy on the nausea of migraine can be indicated.

What the Gut Can Teach Us About Migraine

During gestation, cells of the brain and gut develop almost simultaneously into the central nervous system (CNS) and enteric nervous system (ENS), respectively. They remain connected via the vagal nerve lifelong. While it is well known that the brain sends signal to the gut, communication is in fact bidirectional. Just as the brain can modulate gut functioning, the gut, and likely what we ingest, can in fact influence our brain functioning. We will first review both gastrointestinal (GI) function and migraine pathophysiology and then discuss evidence linking the migraine brain to various GI disorders. Lastly, we discuss the effects of gut microbiota on brain functioning and speculate how the gut and particularly diet may affect migraine.

The pharmacokinetics and clinical efficacy of AVP-825: a potential advancement for acute treatment of migraine

INTRODUCTION

Oral triptans have dominated the prescription market for acute treatment of migraine for nearly 25 years. Today, patients often express dissatisfaction with prescribed acute treatment in part because they do not have confidence that the therapy will provide consistent efficacy over time. Major limitations to sustained successful use of oral triptans are their relatively slow onset of meaningful clinical benefit and variable absorption/efficacy due to impaired gastrointestinal function during migraine. AVP-825, a new intranasal delivery system for sumatriptan , may be an effective alternative to oral triptans.

AREAS COVERED

This article reviews AVP-825, which deposits low-dose sumatriptan powder deep into the vascular mucosa of the posterior nose, allowing rapid absorption of drug into the systemic circulation. Studies suggest that AVP-825 is a highly effective, well-tolerated acute treatment for episodic migraine.

EXPERT OPINION

Oral triptans are limited in providing effective patient-centered outcomes to migraine patients. Failed or suboptimal abortive treatment of migraine is a major driver of migraine chronification and increases in healthcare costs. AVP-825 is an easy to use, novel, breath-powered intranasal delivery system that provides early onset of efficacy with low systemic drug exposure and few triptan-associated adverse events. AVP-825 will be a welcomed therapeutic tool for the acute treatment of migraine.

A novel intranasal breath-powered delivery system for sumatriptan: a review of technology and clinical application of the investigational product AVP-825 in the treatment of migraine

INTRODUCTION

AVP-825, formerly 'OptiNose Sumatriptan,' is an investigational Breath-Powered(TM) Bi-Directional(TM) intranasal delivery system containing low-dose sumatriptan (22 mg intranasal powder) that avoids limitations of other types of intranasal administration by taking advantage of unique features of nasal anatomy and physiology.

AREAS COVERED

This review summarizes intranasal drug delivery for migraine, how the breath-powered technology works, and AVP-825 pharmacokinetic, efficacy and safety/tolerability findings. To identify AVP-825 clinical studies, a PubMed/MEDLINE database search was conducted with the terms AVP-825, OptiNose, OptiNose Sumatriptan, Breath-Powered Nasal Delivery or sumatriptan powder. Of 20 articles, 5 clinical studies were identified, including the head-to-head comparative COMPASS trial (AVP-825 vs oral sumatriptan) and two placebo-controlled studies.

EXPERT OPINION

AVP-825 has faster sumatriptan absorption versus oral tablets or traditional liquid nasal spray. In Phase II/III randomized, double-blind, placebo-controlled trials, AVP-825 produced early and sustained efficacy with minimal triptan-related adverse effects. In COMPASS, AVP-825 produced earlier reduction of migraine pain intensity and migraine-associated symptoms than 100 mg oral sumatriptan, and higher early rates of pain relief and pain freedom, similar sustained efficacy, and fewer atypical sensations. AVP-825 has the potential to provide migraine patients with improved intranasal administration of sumatriptan that may enhance efficacy and tolerability.

Migraine associated with gastrointestinal disorders: review of the literature and clinical implications

Recent studies suggest that migraine may be associated with gastrointestinal (GI) disorders, including irritable bowel syndrome (IBS), inflammatory bowel syndrome, and celiac disease. Here, an overview of the associations between migraine and GI disorders is presented, as well as possible mechanistic links and clinical implications. People who regularly experience GI symptoms have a higher prevalence of headaches, with a stronger association with increasing headache frequency. Children with a mother with a history of migraine are more likely to have infantile colic. Children with migraine are more likely to have experienced infantile colic compared to controls. Several studies demonstrated significant associations between migraine and celiac disease, inflammatory bowel disease, and IBS. Possible underlying mechanisms of migraine and GI diseases could be increased gut permeability and inflammation. Therefore, it would be worthwhile to investigate these mechanisms further in migraine patients. These mechanisms also give a rationale to investigate the effects of the use of pre- and probiotics in migraine patients.

Breath powered nasal delivery: a new route to rapid headache relief

The nose offers an attractive noninvasive alternative for drug delivery. Nasal anatomy, with a large mucosal surface area and high vascularity, allows for rapid systemic absorption and other potential benefits. However, the complex nasal geometry, including the narrow anterior valve, poses a serious challenge to efficient drug delivery. This barrier, plus the inherent limitations of traditional nasal delivery mechanisms, has precluded achievement of the full potential of nasal delivery. Breath Powered bi-directional delivery, a simple but novel nasal delivery mechanism, overcomes these barriers. This innovative mechanism has now been applied to the delivery of sumatriptan. Multiple studies of drug deposition, including comparisons of traditional nasal sprays to Breath Powered delivery, demonstrate significantly improved deposition to superior and posterior intranasal target sites beyond the nasal valve. Pharmacokinetic studies in both healthy subjects and migraineurs suggest that improved deposition of sumatriptan translates into improved absorption and pharmacokinetics. Importantly, the absorption profile is shifted toward a more pronounced early peak, representing nasal absorption, with a reduced late peak, representing predominantly gastrointestinal (GI) absorption. The flattening and “spreading out” of the GI peak appears more pronounced in migraine sufferers than healthy volunteers, likely reflecting impaired GI absorption described in migraineurs. In replicated clinical trials, Breath Powered delivery of low-dose sumatriptan was well accepted and well tolerated by patients, and onset of pain relief was faster than generally reported in previous trials with noninjectable triptans. Interestingly, Breath Powered delivery also allows for the potential of headache-targeted medications to be better delivered to the trigeminal nerve and the sphenopalatine ganglion, potentially improving treatment of various types of headache. In brief, Breath Powered bi-directional intranasal delivery offers a new and more efficient mechanism for nasal drug delivery, providing an attractive option for improved treatment of headaches by enabling or enhancing the benefits of current and future headache therapies.

Dietary considerations in migraine management: does a consistent diet improve migraine?

The clinical expression of migraine is significantly impacted by dietary and gastrointestinal issues. This includes gut dysfunction during and between attacks, food triggers, increase in migraine with obesity, comorbid GI and systemic inflammation influenced by diet, and specific food allergies such as dairy and gluten. Practitioners often encourage migraineurs to seek consistency in their lifestyle behaviors, and environmental exposures, as a way of avoiding sudden changes that may precipitate attacks. However, rigorous evidence linking consistency of diet with improvement in migraine is very limited and is, at best, indirect, being based mainly on the consistency of avoiding suspected food triggers. A review of current data surrounding the issue of dietary consistency is presented from the perspective of migraine as an illness (vulnerable state), as a disease (symptom expression traits), and with a view toward the role of local and systemic inflammation in its genesis. Firm recommendations await further investigation.

Why does vomiting stop a migraine attack?

Migraine is commonly associated with nausea and vomiting, though, interestingly, vomiting has also been reported by some patients to be therapeutic, and may actually stop a migraine attack. In this review, we will first discuss the epidemiology of nausea and vomiting in migraine. Further, we will briefly review the connections between the enteric nervous system, the autonomic nervous system, and the central nervous system as they pertain to understanding the question of "Why does vomiting stop a migraine attack?"

Improved pharmacokinetics of sumatriptan with Breath Powered™ nasal delivery of sumatriptan powder

Objectives.—

The purpose of this study was to directly compare the pharmacokinetic (PK) profile of 22-mg sumatriptan powder delivered intranasally with a novel Breath Powered™ device (11 mg in each nostril) vs a 20-mg sumatriptan liquid nasal spray, a 100-mg oral tablet, and a 6-mg subcutaneous injection.

Background.—

A prior PK study found that low doses of sumatriptan powder delivered intranasally with a Breath Powered device were efficiently and rapidly absorbed. An early phase clinical trial with the same device and doses found excellent tolerability with high response rates and rapid onset of pain relief, approaching the benefits of injection despite significantly lower predicted drug levels.

Methods.—

An open-label, cross-over, comparative bioavailability study was conducted in 20 healthy subjects at a single center in the USA. Following randomization, fasted subjects received a single dose of each of the 4 treatments separated by a 7-day washout. Blood samples were taken pre-dose and serially over 14 hours post-dose for PK analysis.

Results.—

Quantitative measurement of residuals in used Breath Powered devices demonstrated that the devices delivered 8 ± 0.9 mg (mean ± standard deviation) of sumatriptan powder in each nostril (total dose 16 mg). Although the extent of systemic exposure over 14 hours was similar following Breath Powered delivery of 16-mg sumatriptan powder and 20-mg liquid nasal spray (area under the curve [AUC]0-∞ 64.9 ng*hour/mL vs 61.1 ng*hour/mL), sumatriptan powder, despite a 20% lower dose, produced 27% higher peak exposure (Cmax 20.8 ng/mL vs 16.4 ng/mL) and 61% higher exposure in the first 30 minutes compared with the nasal spray (AUC0-30 minutes 5.8 ng*hour/mL vs 3.6 ng*hour/mL). The magnitude of difference is larger on a per-milligram basis. The absorption profile following standard nasal spray demonstrated bimodal peaks, consistent with lower early followed by higher later absorptions. In contrast, the profile following Breath Powered delivery showed higher early and lower late absorptions. Relative to the 100-mg oral tablet (Cmax 70.2 ng/mL, AUC0-∞, 308.8 ng*hour/mL) and 6-mg injection (Cmax 111.6 ng/mL, AUC0-∞ 128.2 ng*hour/mL), the peak and overall exposure following Breath Powered intranasal delivery of sumatriptan powder was substantially lower.

Conclusions.—

Breath Powered intranasal delivery of sumatriptan powder is a more efficient form of drug delivery, producing a higher peak and earlier exposure with a lower delivered dose than nasal spray and faster absorption than either nasal spray or oral administration. It also produces a significantly lower peak and total systemic exposure than oral tablet or subcutaneous injection.