Cannabinoid Receptor Type 1 and mu-Opioid Receptor Polymorphisms Are Associated With Cyclic Vomiting Syndrome

Cyclic Vomiting Syndrome in Adults at the National Level: Impact of Demographics, Burden of Comorbidities, Effect of Hospital Factors, and Determinants of Mortality

GOALS

The aim of this study was to assess clinical, economic, and epidemiological characteristics of hospitalized patients in the United States with cyclic vomiting syndrome (CVS).

BACKGROUND

CVS is a poorly understood disorder of gut-brain interaction (DGBI) characterized by recurring episodes of intractable nausea and vomiting.

STUDY

The study utilized the Healthcare Cost and Utilization Project's National Inpatient Sample between 2016 and 2019. χ2 test and logistic regression were performed to compare the variables. All analyses included sample weights, strata, and clusters to account for the complex survey design.

RESULTS

Admission rates declined from 11,055 in 2016 to 8625 in 2019. Mean age (34.7 y), females (62.5%), and racial distribution (61.8% white) remained stable. Patients were more likely to be 18 to 30 years old (37.2%) and female (62.5%). Comorbidities included anxiety/depression (38.6%) and cannabis use (35.0%). Overall, 90.4% were discharged routinely (ie, to home). Older age (P=0.002) and female gender (P<0.001) had higher length of stay (LOS) and charges. Hispanics incurred higher costs (P<0.001). Depression/anxiety comorbidity (P<0.001) and teaching hospitals (P<0.001) were associated with significantly higher LOS and cost.

CONCLUSIONS

The number of hospitalizations declined between 2016 and 2019, with the latter having 8625 hospitalizations costing over $300 million. Young females represent a larger group, African Americans were disproportionally affected, and Hispanics had the highest hospitalization costs. Anxiety and depression are primary comorbidities. The disparities identified can help clinicians identify riskier CVS patients who may become a burden on the healthcare system, stratifying them for closer monitoring with the goal of improved outcomes.

Cyclic vomiting syndrome: Future clinical and research priorities for: Special supplement/proceedings of 3rd international symposium

BACKGROUND

An increasing number of studies have explored the clinical features, epidemiology, pathophysiology, and management of cyclic vomiting syndrome (CVS). CVS is common in adults and children and negatively impacts patients, families, and the healthcare system. A related condition, cannabinoid hyperemesis syndrome (CHS), has been a focus of interest in the lay press and published literature.

PURPOSE

Clinical presentations of CVS have been defined by small series and expert opinion, but recent prospective studies are refining our understanding of the spectrum of emetic episodes and the breadth of comorbid conditions. Large cross-sectional population analyses are clarifying CVS prevalence and factors related to age, ethnicity, and geographic region. CVS pathophysiology is multifactorial with contributions from migraines, dysautonomia, endogenous cannabinoids, mitochondrial dysfunction, genetic abnormalities, and rapid gastric emptying. CVS treatment relies on antiemetics and antimigraine therapies to abort acute episodes coupled with prophylactic regimens employing neuromodulators and antiepileptics. CHS represents a challenge partly because of difficulties in achieving sustained cannabis abstinence. Benefits of other therapies in CHS remain poorly defined. Several areas warrant further scrutiny including better identification of CVS triggers and characterization of different CVS subsets including those with frequent severe episodes, refined description of epidemiology to allow targeting of populations predisposed to CVS development, rigorous definition of pathogenic factors to provide a foundation for exploratory studies of novel therapies, and conduct of controlled trials by multicenter collaborations to confirm benefits of existing and new therapies in development. Progress in these areas will be facilitated by generous governmental and industry support.

Landscape of Cyclic Vomiting Syndrome: From Bedside to Bench, Past to Present

Investigations into mechanisms of cyclic(al) vomiting syndrome (CVS) began at the bedside more than a century ago. The modern era started with the formation of the Cyclic Vomiting Syndrome Association in 1993 that helped initiate robust efforts in education, advocacy, family physician conferences, scientific symposia, dedicated clinical programs, therapeutic guidelines, and research. Even today, bedside clues continue to emerge with the recent description of cannabinoid hyperemesis syndrome (CHS) and subsequent evidence of a perturbed endocannabinoid system. The clinical picture of CVS has evolved from that of a straightforward emetic disorder related to migraine requiring short-term antiemetics or prophylactic anti-migraine therapy, to a complicated, heterogenous one with multiple comorbid associations (anxiety, dysautonomia) and endophenotypes (migraine, Sato, CHS). This expanded view has important therapeutic implications which necessitate managing the comorbidities which can in turn impact the disease itself and proffered promising evidence that behavioral management (meditation) and vagal neuromodulation appear efficacious with few untoward effects, perhaps by reestablishing autonomic (parasympathetic) balance. The pathophysiologic picture now appears to be inscribed on an autonomic polyvagal design but multiple additional pathways interact, some confirmed (NK1, CB1, HPA axis, PPM1D gene, biological calendar, estrogen), and others, possible (TRPV-1, CGRP, GDF-15, mitochondrial dysfunction, impaired cation transport). CVS and its cousin CHS continue to challenge clinicians and perplex investigators and in the current era require not only a critical mass of specific pathway expertise but also syncretic biopsychosocial thinking to integrate these disparate threads. We may have reached such a tipping point at this Symposium.

Endocannabinoid signaling in stress, nausea, and vomiting

BACKGROUND

Classical antiemetics that target the serotonin system may not be effective in treating certain nausea and vomiting conditions like cyclic vomiting syndrome (CVS) and cannabinoid hyperemesis syndrome (CHS). As a result, there is a need for better therapies to manage the symptoms of these disorders, including nausea, vomiting, and anxiety. Cannabis is often used for its purported antiemetic and anxiolytic effects, given regulation of these processes by the endocannabinoid system (ECS). However, there is considerable evidence that cannabinoids can also produce nausea and vomiting and increase anxiety in certain instances, especially at higher doses. This paradoxical effect of cannabinoids on nausea, vomiting, and anxiety may be due to the dysregulation of the ECS, altering how it maintains these processes and contributing to the pathophysiology of CVS or CHS.

PURPOSE

The purpose of this review is to highlight the involvement of the ECS in the regulation of stress, nausea, and vomiting. We discuss how prolonged cannabis use, such as in the case of CHS or heightened stress, can dysregulate the ECS and affect its modulation of these functions. The review also examines the evidence for the roles of ECS and stress systems' dysfunction in CVS and CHS to better understand the underlying mechanisms of these conditions.

Cannabinoid hyperemesis syndrome: genetic susceptibility to toxic exposure

Cannabinoid hyperemesis syndrome presents as a complex of symptoms and signs encompassing nausea, vomiting, abdominal pain, and hot water bathing behavior, most typically in a heavy cannabis user. Its presentation is frequently associated with hypothalamic-pituitary-adrenal axis activation with stress and weight loss. Recent investigation has identified five statistically significant mutations in patients distinct from those of frequent cannabis users who lack the symptoms, affecting the TRPV1 receptor, two dopamine genes, the cytochrome P450 2C9 enzyme that metabolizes tetrahydrocannabinol, and the adenosine triphosphate-binding cassette transporter. The syndrome is associated with escalating intake of high potency cannabis, or alternatively, other agonists of the cannabinoid-1 receptor including synthetic cannabinoids. Some patients develop environmental triggers in scents or foods that suggest classical conditioned responses. Various alternative "causes" are addressed and refuted in the text, including exposure to pesticides, neem oil or azadirachtin. Nosological confusion of cannabinoid hyperemesis syndrome has arisen with cyclic vomiting syndrome, whose presentation and pathophysiology are clearly distinct. The possible utilization of non-intoxicating antiemetic cannabis components in cannabis for treatment of cannabinoid hyperemesis syndrome is addressed, along with future research suggestions in relation to its genetic foundation and possible metabolomic signatures.

Acute and Long-Term Effects of App-Delivered Heartfulness Meditation on Psychological Outcomes and the Endocannabinoid Signaling System in Cyclic Vomiting Syndrome

INTRODUCTION

Cyclic vomiting syndrome (CVS) is a disorder of gut-brain interaction often triggered by stress. Interventions such as meditation may improve psychological outcomes and health-related quality of life (HRQoL), but their efficacy and the underlying mechanism are unknown.

METHODS

We conducted a 6-week single-arm pilot study to assess the effects of heartfulness meditation (HFM) in CVS using a custom-designed meditation app. Primary outcomes included state and trait anxiety and mood state changes pre vs post-meditation, and secondary outcomes were psychological distress, coping, sleep quality, and HRQoL at baseline and at weeks 3 and 6. Serum concentrations of endocannabinoids N -arachidonylethanolamine and 2-arachidonoylglycerol and related lipids were measured pre- and post-HFM at baseline and week 6.

RESULTS

In 30 treatment completers, there was a significant improvement in state anxiety ( P < 0.001), total mood disturbance ( P < 0.001), and other mood states (all P values < 0.05) across the 3 time points. Trait anxiety was also improved at week 6. There was a significant improvement in psychological distress (Global Severity Index), sleep quality (daytime dysfunction), coping (using religion/spirituality), and HRQoL (mental and physical) across the 3 time points (all P < 0.05). Significant increases in N -arachidonylethanolamine and related lipids N -oleoylethanolamine and palmitoylethanolamide post vs pre-HFM were observed at week 6 ( P < 0.001, 0.002, 0.003, respectively). No adverse effects were noted.

DISCUSSION

App-delivered HFM is feasible, safe, and effective and improves psychological outcomes and augments endocannabinoids. This provides insight into the mechanism underlying HFM and has potential for widespread use as a digital therapeutic in CVS and other disorder of gut-brain interaction.

Cyclic vomiting syndrome: From pathophysiology to treatment

Cyclic vomiting syndrome (CVS) is a disorder characterized by recurrent and unpredictable episodes of intense vomiting, interspersed with periods of apparent wellbeing. This disorder, which primarily affects children and adolescents but can persist into adulthood, has recently been the subject of extensive study and analysis in the medical literature. The aim of the present review is to examine the most important aspects of the epidemiology, pathophysiology, subtypes, diagnostic criteria, and current management of CVS. Even though the exact etiology remains unknown, genetic factors (polymorphisms), nervous system alterations and autonomic dysregulation, and environmental factors (use and abuse of cannabinoids) are postulated as possible triggers. CVS has significant diagnostic challenges, given that there is no specific test for confirming its presence. Thorough evaluation of symptoms and the ruling out of other possible causes of recurrent vomiting are required. Management of CVS typically involves a multidisciplinary approach. Pharmacologic options are explored, such as antiemetics and preventive medications, as well as behavioral and psychologic support therapies. Treatment personalization is essential, adapting it to the individual needs of each patient. Despite advances in the understanding of CVS, it remains a significant clinical challenge. This disorder impacts the quality of life of those affected and their families, underscoring the ongoing need for research and the development of more effective treatment strategies.

Cannabis use in the United States and its impact on gastrointestinal health

In recent years, the legalization and social acceptability of cannabis use have increased in the United States. Concurrently, the prevalence of cannabis use has continued to rise, and cannabis products have diversified. There are growing concerns regarding the health effects of regular and high-potency cannabis use, and new research has shed light on its potentially negative effects. Here, we review evidence of the gastrointestinal (GI) effects of cannabis and cannabinoids. Dysregulation of the endocannabinoid system might contribute to various GI disorders, including irritable bowel syndrome and cyclic vomiting syndrome, and endocannabinoids have been found to regulate visceral sensation, nausea, vomiting, and the gut microbiome. Cannabis has been shown to have antiemetic properties, and the US Food and Drug Administration has approved cannabis-based medications for treating chemotherapy-induced nausea and vomiting. Yet, chronic heavy cannabis use has been linked to recurrent episodes of severe nausea and intractable vomiting (cannabinoid hyperemesis syndrome). Given the considerable heterogeneity in the scientific literature, it is unclear if cannabinoid hyperemesis syndrome is truly a distinct entity or a subtype of cyclic vomiting that is unmasked by heavy cannabis use and the associated dysregulation of the endocannabinoid system. The changes in cannabis legalization, availability, and public risk perceptions have outpaced research in this area and there is a need for robust, prospective, large-scale studies to understand the effects of cannabis use on GI health.

Plasma endocannabinoids and cannabimimetic fatty acid derivatives are altered in cyclic vomiting syndrome: The effects of sham feeding

Cyclic vomiting syndrome (CVS) is an underdiagnosed disorder of the gut-brain interaction. Our understanding of the pathophysiology of CVS is evolving. Here, we tested the hypotheses that: (1) the levels of endocannabinoids and related lipids are altered in CVS, and (2) cephalic-vagal stimulation drive changes in endolipid levels. Ten adult patients with CVS and eight healthy controls were included. Indirect measurements of parasympathetic (RFa) functions were performed with spectral analysis of heart rate variability and respiratory activity. Plasma levels of endocannabinoids and related lipids were measured at baseline and during a sham feeding. Values are reported as mean ± standard error of the mean and compared using t-test or ANOVA. CVS patients had a lower parasympathetic tone and response to the Valsalva maneuver and deep breathing than the controls. The baseline 2-Arachidonoylglycerol (2-AG) had a significantly higher concentration in CVS (5.9e-008 ± 3.7e-008 mol/L) than control (3.7e-008 ± 1.3e-008 mol/; p < 0.05). Sham feeding did not change the concentration of 2-AG. 2-oleoylglycerol (2-OG) was significantly higher in CVS than control and did not change with sham feeding. Levels of N-acylethanolamines, including anandamide (AEA), were not different in CVS vs control. After sham feeding, AEA showed a trend toward increasing (p = 0.08) in CVS, but not in control. With sham feeding, palmitoyl ethanolamine significantly increased in both CVS and control groups; oleoyl ethanolamine in CVS only, and stearoyl ethanolamine in the control group. Levels of endocannabinoids and related lipids are altered in CVS patients. Sham feeding affects endogenous signaling lipids in a disease and time-dependent manner.

Whole exome/genome sequencing in cyclic vomiting syndrome reveals multiple candidate genes, suggesting a model of elevated intracellular cations and mitochondrial dysfunction

OBJECTIVE

To utilize whole exome or genome sequencing and the scientific literature for identifying candidate genes for cyclic vomiting syndrome (CVS), an idiopathic migraine variant with paroxysmal nausea and vomiting.

METHODS

A retrospective chart review of 80 unrelated participants, ascertained by a quaternary care CVS specialist, was conducted. Genes associated with paroxysmal symptoms were identified querying the literature for genes associated with dominant cases of intermittent vomiting or both discomfort and disability; among which the raw genetic sequence was reviewed. "Qualifying" variants were defined as coding, rare, and conserved. Additionally, "Key Qualifying" variants were Pathogenic/Likely Pathogenic, or "Clinical" based upon the presence of a corresponding diagnosis. Candidate association to CVS was based on a point system.

RESULTS

Thirty-five paroxysmal genes were identified per the literature review. Among these, 12 genes were scored as "Highly likely" (SCN4A, CACNA1A, CACNA1S, RYR2, TRAP1, MEFV) or "Likely" (SCN9A, TNFRSF1A, POLG, SCN10A, POGZ, TRPA1) CVS related. Nine additional genes (OTC, ATP1A3, ATP1A2, GFAP, SLC2A1, TUBB3, PPM1D, CHAMP1, HMBS) had sufficient evidence in the literature but not from our study participants. Candidate status for mitochondrial DNA was confirmed by the literature and our study data. Among the above-listed 22 CVS candidate genes, a Key Qualifying variant was identified in 31/80 (34%), and any Qualifying variant was present in 61/80 (76%) of participants. These findings were highly statistically significant (p < 0.0001, p = 0.004, respectively) compared to an alternative hypothesis/control group regarding brain neurotransmitter receptor genes. Additional, post-analyses, less-intensive review of all genes (exome) outside our paroxysmal genes identified 13 additional genes as "Possibly" CVS related.

CONCLUSION

All 22 CVS candidate genes are associated with either cation transport or energy metabolism (14 directly, 8 indirectly). Our findings suggest a cellular model in which aberrant ion gradients lead to mitochondrial dysfunction, or vice versa, in a pathogenic vicious cycle of cellular hyperexcitability. Among the non-paroxysmal genes identified, 5 are known causes of peripheral neuropathy. Our model is consistent with multiple current hypotheses of CVS.

Cyclic Vomiting Syndrome and Cannabis Hyperemesis Syndrome: The State of the Science

This article provides a narrative review of the state of the science for both cyclic vomiting syndrome and cannabis hyperemesis syndrome along with a discussion of the relationship between these 2 conditions. The scope of this review includes the historical context of these conditions as well as the prevalence, diagnostic criteria, pathogenesis, and treatment strategies for both conditions. A synopsis of the endocannabinoid system provides a basis for the hypothesis that a lack of cannabidiol in modern high-potency Δ 9 -tetrahydrocannabinol cannabis may be contributory to cannabis hyperemesis syndrome and possibly other cannabis use disorders. In concluding assessment, though the publications addressing both adult cyclic vomiting syndrome and cannabis hyperemesis syndrome are steadily increasing overall, the state of the science supporting the treatments, prognosis, etiology, and confounding factors (including cannabis use) is of moderate quality. Much of the literature portrays these conditions separately and as such sometimes fails to account for the confounding of adult cyclic vomiting syndrome with cannabis hyperemesis syndrome. The diagnostic and therapeutic approaches are, at present, based generally on case series publications and expert opinion, with a very limited number of randomized controlled trials and a complete absence of Level 1 evidence within the cyclic vomiting literature overall as well as for cannabis hyperemesis syndrome specifically.

Diagnosis and Management of Cyclic Vomiting Syndrome: A Critical Review

Cyclic vomiting syndrome (CVS) is a chronic disorder of gut-brain interaction characterized by recurrent disabling episodes of nausea, vomiting, and abdominal pain. CVS affects both children and adults with a prevalence of approximately 2% in the United States. CVS is more common in female individuals and affects all races. The pathophysiology of CVS is unknown and a combination of genetic, environmental, autonomic, and neurohormonal factors is believed to play a role. CVS is also closely associated with migraine headaches and likely have a shared pathophysiology. The diagnosis of CVS is based on the Rome criteria, and minimal recommended testing includes an upper endoscopy and imaging studies of the abdomen. CVS is frequently associated with anxiety, depression, and autonomic dysfunction. Patients with CVS commonly use cannabis therapeutically for symptom relief. By contrast, cannabinoid hyperemesis syndrome is believed to be a subset of CVS with chronic heavy cannabis use leading to hyperemesis. Due to the recalcitrant nature of the illness, patients often visit the emergency department and are hospitalized for acute CVS flares. Guidelines on the management of CVS recommend a biopsychosocial approach. Prophylactic therapy consists of tricyclic antidepressants (amitriptyline), antiepileptics (topiramate), and aprepitant in refractory patients. Abortive therapy consists of triptans, antiemetics (ondansetron), and sedation. Treatment of comorbid conditions is extremely important to improve overall patient outcomes. CVS has a significant negative impact on patients, families, and the healthcare system, and future research to understand its pathophysiology and develop targeted therapies is needed.

Abdominal migraine and cyclical vomiting syndrome

Abdominal migraine and cyclical vomiting syndrome (CVS) are characteristic syndromes which have overlapping characteristics with migraine but lack the cardinal symptom of headache. Both abdominal migraine and CVS are characterized by recurrent attacks of nausea, vomiting, and/or abdominal pain lasting hours to a few days, with symptom freedom between attacks. Both abdominal migraine and CVS typically occur in children and adolescents, who often go on to develop more typical migraine headaches when older, but may also present for the first time in adults. Due to their shared characteristics and association with migraine headaches, abdominal migraine and CVS are sometimes called "migraine equivalents," and their pathophysiology is assumed to overlap with migraine headache. This chapter describes what is known about the clinical characteristics, epidemiology, pathophysiology, and prognosis of abdominal migraine and CVS, and explores their relationship to migraine. We also review the existing evidence for the nonpharmacological management, acute treatment of attacks, and preventive treatments for both abdominal migraine and CVS.

[Clinical and gastroscopic features of children with cyclic vomiting syndrome: an analysis of 63 cases]

OBJECTIVES

To study the clinical and gastroscopic features of children with cyclic vomiting syndrome.

METHODS

A retrospective analysis was performed on the medical data of 63 children with cyclic vomiting syndrome who were hospitalized and followed up in Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University from August 2019 to March 2022.

RESULTS

Among the 63 children, there were 30 boys and 33 girls, with a mean age of 6.11 years, a mean course of disease of 2.57 years, and a mean vomiting period of 4.04 days. The most common accompanying symptom was listlessness or somnolence (55/63, 87%), followed by anorexia (45/63, 71%), abdominal pain or abdominal discomfort (40/63, 63%), constipation (19/63, 30%), salivation (12/63, 19%), nausea (11/63, 17%), headache (11/63, 17%), fever (6/63, 10%), and rash (1/63, 2%). All 63 children underwent gastroscopy, among whom 3 had no marked abnormalities, 22 (35%) had chronic superficial gastritis or chronic non-atrophic gastritis alone, and 38 (60%) had other abnormal changes aside from chronic gastritis (16 children with reflux esophagitis, 12 with bile reflux gastritis, 13 with duodenitis, 10 with erosive gastritis, and 5 with gastric or duodenal ulcer). Among the 63 children, 42 underwent pathological examinations of gastric mucosa, among whom 5 had no marked abnormalities, 34 had mild chronic gastritis, 2 had moderate chronic gastritis, and 1 had severe chronic gastritis. Among the 63 children, 15 received 24-hour dynamic esophageal pH monitoring during the interictal period, among whom 9 children were found to have pathological acid reflux.

CONCLUSIONS

In addition to recurrent vomiting, most children with cyclic vomiting syndrome also have the symptoms such as somnolence or listlessness, anorexia, and abdominal pain. The main manifestation on gastroscopy is chronic gastritis, and most children may also have reflux esophagitis, bile reflux gastritis, and erosive gastritis. Mild chronic gastritis is the main pathological change of gastric mucosa.

Cannabinoid hyperemesis syndrome in North America: evaluation of health burden and treatment prevalence

BACKGROUND

Cannabinoid hyperemesis syndrome (CHS) is a poorly understood vomiting disorder associated with chronic cannabis use.

AIMS

To characterise patients experiencing CHS in North America and to obtain a population-based estimate of CHS treatment prevalence in Canada before and during the Covid-19 pandemic METHODS: Internet survey of 157 CHS sufferers in Canada and the United States. Administrative health databases for the province of Alberta (population 5 million) were accessed to measure emergency department (ED) visits for vomiting, with a concurrent diagnostic code for cannabis use. Three time periods of 1 year were assessed: prior to recreational cannabis legalisation (2017-2018), after recreational legalisation (2018-2019) and during the first year of the Covid-19 pandemic (2020-2021).

RESULTS

Problematic cannabis use (defined as a CUDIT-R score ≥8) was universal among the survey cohort, and 59% and 68% screening for moderate or worse anxiety or depression, respectively. The overall treatment prevalence of CHS across all ages increased from 15 ED visits per 100,000 population (95% CI, 14-17) prior to legalisation, to 21 (95% CI, 20-23) after legalisation, to 32 (95% CI, 31-35) during the beginning of the Covid-19 pandemic (p < 0.001). Treatment prevalence among chronic cannabis users was as high as 6 per 1000 in the 16-24 age group.

CONCLUSION

Survey data suggest patients with CHS almost universally suffer from a cannabis use disorder, which has significant treatment implications. Treatment prevalence in the ED has increased substantially over a very short time period, with the highest rates seen during the Covid-19 pandemic.

Current understanding of the etiology of cyclic vomiting syndrome and therapeutic strategies in its management

INTRODUCTION

Cyclic vomiting syndrome is a chronic debilitating disorder of the gut-brain interaction and is characterized by recurrent episodes of nausea and vomiting.Recent studies indicate that it is common and affects 2% of the US population. Unfortunately, there is significant heterogeneity in the management of these patients in the medical community. This review article aims to bridge this gap and will review the epidemiology and etiology with a focus on management of CVS.

AREAS COVERED

This article reviews the epidemiology, and pathophysiology of CVS and impact on patients. It also discusses management based on recent guidelines based on which is intended for the busy clinician. A literature search was done using PubMed and key words "cyclic vomiting", "management", "etiology", and pathophysiology were used to identify articles of importance.

EXPERT OPINION

CVS is a complex, poorly understood disorder of gut-brain interaction (DGBI) and has a significant negative impact on patients, families and the healthcare system. Recent guidelines recommend a multidisciplinary approach to management using prophylactic therapy in moderate-severe CVS and abortive medication for acute flares. However more research is needed to better understand the pathophysiology and develop targeted therapies for CVS.

Low patient engagement is associated with reduced health-related quality of life in adults with cyclic vomiting syndrome

INTRODUCTION

Patient engagement, adaptation and self-management play a critical role in improving Health Related Quality of Life (HRQOL) and reducing health care utilization in chronic disorders. There is no data on the level of patient engagement in patients with cyclic vomiting syndrome (CVS); we thus sought to determine their level of engagement and its association with clinical covariates.

METHODS

The Patient Activation Measure (PAM-13), a validated tool that measures the degree of patient engagement in their health was administered prospectively to patients with CVS. Data on demographics, health care utilization, and HRQOL (using the NIH PROMIS 10) were obtained. Patients were stratified into low engagement (PAM 1 & 2) and high engagement (PAM 3 & 4). The Fisher's exact test and Wilcoxon rank-sum tests were used to identifying significant differences between the groups.

RESULTS

Of 96 patients, 45% of patients had low levels of patient engagement. On multivariate analysis, low patient engagement was significantly associated with an increased number of CVS hospitalizations in the past year (aOR 1.26 [1.07, 1.54] p = .010), lower mental HRQOL scores (aOR 0.88 [0.78, 0.97] p = .022), current tobacco use (aOR 4.85 [1.24, 22.74] p = .031), and patients who were newly established in a specialized CVS clinic (aOR 44.40 [5.38, 70.02] p = .002).

CONCLUSION

Almost half of CVS patients demonstrate poor patient engagement, which is associated with poor outcomes. Identifying these patients and treatment in a specialized CVS center can potentially improve HRQOL, reduce health care utilization and improve overall healthcare outcomes.

Cannabinoid Hyperemesis Syndrome Survey and Genomic Investigation

Background:

Cannabinoid hyperemesis syndrome (CHS) is a diagnosis of exclusion with intractable nausea, cyclic vomiting, abdominal pain, and hot bathing behavior associated with ongoing tetrahydrocannabinol (THC) exposure. Increasing cannabis use may elevate CHS prevalence, exacerbating a public health issue with attendant costs and morbidity.

Objective, Design, and Data Source:

This study, the largest contemporaneous database, investigated genetic mutations underlying CHS. Patients with CHS diagnosis and ongoing symptoms were compared with current cannabis users lacking symptoms.

Target Population:

A screening questionnaire was posted online. Of 585 respondents, 205 qualified as the CHS pool and 54 as controls; a reduced pool of 28 patients and 12 controls ultimately completed genomic testing.

Results:

Patients and controls were high-frequency users of cannabis flower or concentrates (93%), using multiple grams/day of THC-predominant material. Among patients, 15.6% carried diagnoses of cannabis dependency or addiction, and 56.6% experienced withdrawal symptoms. About 87.7% of patients improved after cannabis cessation, most suffering recurrence rapidly after resumption. Findings in patients included mutations in genes COMT {odds ratio, 12 (95% confidence limit [CL], 1.3–88.1) p=0.012}, transient receptor potential vanilloid receptor 1 (TRPV1) (odds ratio, 5.8 [95% CL, 1.2–28.4] p=0.015), CYP2C9 (odds ratio, 7.8 [95% CL, 1.1–70.1] p=0.043), gene coding dopamine-2 receptor (DRD2) (odds ratio, 6.2 [95% CL, 1.1–34.7] p=0.031), and ATP-binding cassette transporter gene (ABCA1) (odds ratio, 8.4 [95% CL, 1.5–48.1] p=0.012).

Limitations:

Some participants were reluctant to undergo genetic testing; only 28 of 99 CHS patients who agreed to testing ultimately returned a kit.

Conclusion:

This is the largest patient cohort of CHS examined to date, and first to note associated mutations in genes affecting neurotransmitters, the endocannabinoid system, and the cytochrome P450 complex associated with cannabinoid metabolism. Although the sample size was smaller than desired, these preliminary findings may contribute to the growing body of knowledge, stimulate additional investigation, help elucidate the pathophysiology of CHS, and, ultimately, direct future treatment.

The childhood migraine syndrome

Migraine is a complex genetic brain disorder with an intricate pathogenesis and polymorphous clinical presentations, particularly in children. In this Perspective, we describe the different phenotypes of migraine in children, including conditions that have been referred to in the International Classification of Headache Disorders as "syndromes that may be related to migraine''. Evidence is presented for the integration of abdominal migraine, cyclical vomiting syndrome, benign paroxysmal vertigo, benign paroxysmal torticollis and infantile colic into the unified diagnosis of 'childhood migraine syndrome' on the basis of clinical and epidemiological characteristics, and shared inheritance. In our opinion, such integration will guide clinicians from specialities other than neurology to consider migraine in the assessment of children with these disorders, as well as stimulate research into the genetics, pathophysiology and clinical features of all disorders within the syndrome. A diagnosis of childhood migraine syndrome would also enable patients to benefit from inclusion in clinical trials of old and new migraine treatments, thus potentially increasing the number of treatment options available.

Plasma endocannabinoids and cannabimimetic fatty acid derivatives are altered in gastroparesis: A sex- and subtype-dependent observation

BACKGROUND

Gastroparesis (GP) is a motility disorder of the stomach presenting with upper gastrointestinal symptoms in the setting of delayed gastric emptying. Endocannabinoids are involved in the regulation of GI function including motility. However, their role in the pathophysiology of GP has not been sufficiently investigated. Our goal was to compare the circulating levels of endocannabinoids and cannabimimetic fatty acid derivatives in GP versus control subjects.

METHODS

The study compared plasma concentrations of endocannabinoids and their lipoamine and 2-acyl glycerol congeners, measured by high-pressure liquid chromatography/tandem mass spectrometry (HPLC-MS-MS), in adult patients with diabetic gastroparesis (DM-GP; n = 24; n = 16 female), idiopathic gastroparesis (ID-GP; n = 19; n = 11 female), diabetic patients without GP (DM; n = 19; n = 10 female), and healthy controls (HC; n = 18; n = 10 female). Data, presented as mean ± SEM, were analyzed with ANOVA (Sidak post hoc).

KEY RESULTS

Endocannabinoids anandamide (AEA: 0.5 ± 0.1 nMol/L) and 2-arachidonoyl glycerol (2-AG: 2.6 ± 0.7 nMol/L) were significantly lower in female DM-GP patients vs. DM females (AEA: 2.5 ± 0.7 nMol/L and 2-AG: 9.4 ± 3.3 nMol/L). Other monoacylglycerols including 2-palmitoyl glycerol and 2-oleoyl glycerol were also lower in female DM-GP patients compared to DM females. No changes were observed in men.

CONCLUSIONS & INFERENCES

Endocannabinoids and other fatty acid derivatives with cannabimimetic properties are reduced in female DM-GP patients. Since GP, particularly with diabetic etiology, is more prevalent among women and since cannabinoids are antiemetic, this decrease in levels may contribute to symptom development in these subjects. Targeting the endocannabinoid system may be a future therapeutic option in DM-GP patients.

Cyclic Vomiting Syndrome in Children

Cyclic Vomiting Syndrome (CVS) is an underdiagnosed episodic syndrome characterized by frequent hospitalizations, multiple comorbidities, and poor quality of life. It is often misdiagnosed due to the unappreciated pattern of recurrence and lack of confirmatory testing. CVS mainly occurs in pre-school or early school-age, but infants and elderly onset have been also described. The etiopathogenesis is largely unknown, but it is likely to be multifactorial. Recent evidence suggests that aberrant brain-gut pathways, mitochondrial enzymopathies, gastrointestinal motility disorders, calcium channel abnormalities, and hyperactivity of the hypothalamic-pituitary-adrenal axis in response to a triggering environmental stimulus are involved. CVS is characterized by acute, stereotyped and recurrent episodes of intense nausea and incoercible vomiting with predictable periodicity and return to baseline health between episodes. A distinction with other differential diagnoses is a challenge for clinicians. Although extensive and invasive investigations should be avoided, baseline testing toward identifying organic causes is recommended in all children with CVS. The management of CVS requires an individually tailored therapy. Management of acute phase is mainly based on supportive and symptomatic care. Early intervention with abortive agents during the brief prodromal phase can be used to attempt to terminate the attack. During the interictal period, non-pharmacologic measures as lifestyle changes and the use of reassurance and anticipatory guidance seem to be effective as a preventive treatment. The indication for prophylactic pharmacotherapy depends on attack intensity and severity, the impairment of the QoL and if attack treatments are ineffective or cause side effects. When children remain refractory to acute or prophylactic treatment, or the episode differs from previous ones, the clinician should consider the possibility of an underlying disease and further mono- or combination therapy and psychotherapy can be guided by accompanying comorbidities and specific sub-phenotype. This review was developed by a joint task force of the Italian Society of Pediatric Gastroenterology Hepatology and Nutrition (SIGENP) and Italian Society of Pediatric Neurology (SINP) to identify relevant current issues and to propose future research directions on pediatric CVS.

Cannabinoid Hyperemesis Syndrome: A Review of Potential Mechanisms

Introduction: Cannabinoids have long been known for their ability to treat nausea and vomiting. Recent reports, however, have highlighted the paradoxical proemetic effects of cannabinoids. Cannabinoid hyperemesis syndrome (CHS) is characterized by cyclical episodes of nausea and vomiting, accompanied by abdominal pain following prolonged, high-dose cannabis use, which is alleviated by hot baths and showers. Little is known about the cause of this syndrome. Discussion: Cannabinoids produce a biphasic effect on nausea and vomiting, with low doses having an antiemetic effect and high doses producing emesis. Presentation and treatment of CHS are similar to cyclical vomiting syndrome as well as chemotherapy-related anticipatory nausea and vomiting, suggesting that these phenomena may share mechanisms. The prevalence of CHS is not known because of the symptomatic overlap with other disorders and the lack of knowledge of the syndrome by the public and physicians. Treatment with typical antiemetic drugs is ineffective for CHS, but anxiolytic and sedative drugs, along with hot showers, seem to be consistently effective at reducing symptoms. The only known way to permanently end CHS, however, is abstinence from cannabinoids. Case studies and limited pre-clinical data on CHS indicate that prolonged high doses of the main psychotropic compound in cannabis, Δ9-tetrahydrocannabinol (THC), result in changes to the endocannabinoid system by acting on the cannabinoid 1 (CB1) receptor. These endocannabinoid system changes can dysregulate stress and anxiety responses, thermoregulation, the transient receptor potential vanilloid system, and several neurotransmitters systems, and are thus potential candidates for mediating the pathophysiology of CHS. Conclusions: Excessive cannabinoid administration disrupts the normal functioning of the endocannabinoid system, which may cause CHS. More clinical and pre-clinical research is needed to fully understand the underlying pathophysiology of this disorder and the negative consequences of prolonged high-dose cannabis use.

Patterns of Cannabis Use in Patients With Cyclic Vomiting Syndrome

BACKGROUND & AIMS

Some patients with cyclic vomiting syndrome (CVS) use cannabis to relieve stress and for its antiemetic properties. However, chronic cannabis use has been associated paradoxically with cannabinoid hyperemesis syndrome (CHS) and some patients with CVS are thought to have CHS. We sought to characterize patterns of cannabis use by patients with CVS and identify those who could be reclassified as having CHS.

METHODS

We performed a cross-sectional study of 140 patients with CVS (72% female; mean age, 37 ± 13 y) seen at a specialized clinic. Patients were screened for cannabis use with the cannabis use disorder identification test. Patients were classified as regular (use ≥4 times/wk) or occasional users (<4 times/wk).

RESULTS

Forty-one percent of patients were current cannabis users, with 21% reporting regular use. Regular users were more likely to be male and to report an anxiety diagnosis, and smoked cannabis with higher tetrahydrocannabinol content and for a longer duration. Most users reported that cannabis helped control CVS symptoms. Among all cannabis users, 50 of 57 (88%) reported that they had abstained for longer than 1 month, but only 1 user reported resolution of CVS episodes during the abstinence period. This patient subsequently resumed using cannabis but remains free of symptoms.

CONCLUSIONS

Cannabis is used commonly among patients with CVS-patients report relief of symptoms with use. We found 21% of patients with CVS to be regular users, but only 1 met the Rome IV criteria for CHS. Longitudinal studies are needed to determine the relationships among cannabis use, hyperemesis, and mood symptoms.

Association of a Variant of CNR1 Gene Encoding Cannabinoid Receptor 1 With Gilles de la Tourette Syndrome

Background

Gilles de la Tourette syndrome (GTS) is a neuropsychiatric disorder of unknown etiology, although a major role of genetic factors has been established. Cannabis-based medicines may alleviate GTS-associated tics and variants of CNR1 gene encoding central cannabinoid receptor (CB1) are believed to be a risk factor for the development of some neurodevelopmental diseases. Our aim was to test the association of selected CNR1 gene variants with GTS.

Material and Methods

The cohort of GTS cases comprised 262 unrelated patients aged 3–53 years (mean age: 18.3 ± 9.1 years; 204 males (77.9%), 126 (48.1%) adults defined as ≥18 years). As a control group we enrolled 279 unrelated, ethnically and gender matched individuals with no diagnosed mental, neurological or general disorder, aged 13–54 years (mean age: 22.5 ± 3.0 years; 200 males, (74.1%). Both study and control groups were selected from Polish population, which is ethnically homogenous subgroup of Caucasian population. Four single nucleotide polymorphisms (SNPs) in CNR1 were selected: rs2023239, rs2180619, rs806379, and rs1049353 based on minor allele frequency in general population >15%. These variants were genotyped using a real-time quantitative polymerase chain reaction system (TaqMan SNP genotyping assay).

Results

We found significant association of GTS clinical phenotype with rs2023239 variant. Minor allele C and CT+CC genotypes were found significantly more often in GTS patients compared to controls (17.4 vs 11.1%, p=0.003 and 32.8 vs 20.4%, p=0.001, respectively), and the difference remained significant after correction for multiple testing. C allele of rs2023239 polymorphism of the CNR1 gene was associated with the occurrence of tics. There were no statistically significant associations for rs806379, rs1049353 or rs2180619 variants.

Conclusion

Our findings suggest that C allele of rs2023239 polymorphism of the CNR1 gene is a risk factor of GTS in Polish population. The variant can be potentially associated with abnormal endocannabinoid transmission, which is suspected to be one of the causes of GTS.

Endogenous opiates and behavior: 2017

This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Cyclic vomiting syndrome: Pathophysiology, comorbidities, and future research directions

Cyclic vomiting syndrome (CVS) is characterized by severe episodic emesis in adults and children. Cannabinoid hyperemesis syndrome is an increasingly recognized CVS-like illness that has been associated with chronic cannabis use. There are significant gaps in our understanding of the pathophysiology, clinical features, comorbidities, and effective management options of CVS. Recommendations for treating CVS are based on limited clinical data, as no placebo-controlled, randomized trials have yet been conducted. Diseases associated with CVS, including migraine, mitochondrial disorders, autonomic dysfunction, and psychiatric comorbidities, provide clues about pathophysiologic mechanisms and suggest potential therapies. We review our current understanding of CVS and propose future research directions with the aim of developing effective therapy. Establishing a multicenter, standardized registry of CVS patients could drive research on multiple fronts including developing CVS-specific outcome measures to broaden our understanding of clinical profiles, to serve as treatment end points in clinical trials, and to provide a platform for patient recruitment for randomized clinical trials. Such a robust database would also facilitate conduct of research that aims to determine the underlying pathophysiological mechanisms and genetic basis for CVS, as well as identifying potential biomarkers for the disorder. Soliciting government and industry support is crucial to establishing the necessary infrastructure and achieving these goals. Patient advocacy groups such as the Cyclic Vomiting Syndrome Association (CVSA), which partner with clinicians and researchers to disseminate new information, to promote ongoing interactions between patients, their families, clinicians, investigators, to support ongoing CVS research and education, must be an integral part of this endeavor.

The ventral pallidum as a critical region for fatty acid amide hydrolase inhibition of nausea-induced conditioned gaping in male Sprague-Dawley rats

Here we investigate the involvement of the ventral pallidum (VP) in the anti-nausea effect of fatty acid amide hydrolase (FAAH) inhibition with PF-3845, and examine the pharmacological mechanism of such an effect. We explored the potential of intra-VP PF-3845 to reduce the establishment of lithium chloride (LiCl)-induced conditioned gaping (a model of acute nausea) in male Sprague-Dawley rats. As well, the role of the cannabinoid 1 (CB₁) receptors and the peroxisome proliferator-activated receptors-α (PPARα) in the anti-nausea effect of PF-3845 was examined. Finally, the potential of intra-VP GW7647, a PPARα agonist, to reduce acute nausea was also evaluated. Intra-VP PF-3845 dose-dependently reduced acute nausea by a PPARα mechanism (and not a CB₁ receptor mechanism). Intra-VP administration of GW7647, similarly attenuated acute nausea. These findings suggest that the anti-nausea action of FAAH inhibition may occur in the VP, and may involve activation of PPARα to suppress acute nausea.

Efficacy of Capsaicin for the Treatment of Cannabinoid Hyperemesis Syndrome: A Systematic Review

Objective: Cannabinoid hyperemesis syndrome (CHS) is characterized by cyclic vomiting, abdominal pain, and alleviation of symptoms via hot showers in chronic cannabinoid users. Capsaicin is recommended as a reasonable first-line treatment approach for CHS despite limited clinical evidence regarding its use. The objective of this study is to systematically review the efficacy data for capsaicin in CHS. Data Sources: A literature search using keywords related to cannabinoids, emesis, and capsaicin was performed in MEDLINE, CINAHL, and EMBASE from inception through March 31, 2019. Study Selection and Data Extraction: Studies and published abstracts in which capsaicin was used for CHS and clinical outcomes were reported were eligible for inclusion. Data Synthesis: A total of 241 articles were screened, of which 5 full-text articles and 6 conference abstracts were included. Full-text case reports (n = 3) and case series (n = 2) found capsaicin to be effective in a total of 18 patients. Published abstracts were in the form of case reports (n = 1), case series (n = 3), and retrospective cohort studies (n = 2). Relevance to Patient Care and Clinical Practice: Capsaicin use was described as beneficial in all case series and case reports; however, both retrospective cohort studies were unable to find a significant benefit for capsaicin on primary outcomes (emergency department length of stay). Conclusion: Current data for capsaicin efficacy in CHS is of low methodological quality. However, the limited data on alternative antiemetic therapies and capsaicin’s favorable risk-benefit profile make it a reasonable adjunctive treatment option.

Epidemiology, Clinical Characteristics, and Associations for Rome IV Functional Nausea and Vomiting Disorders in Adults

BACKGROUND & AIMS

Functional nausea and vomiting disorders (FNVDs) are classified as chronic nausea and vomiting syndrome (CNVS) or cyclic vomiting syndrome (CVS)-CVS includes cannabinoid hyperemesis syndrome. We investigated the population prevalence of FNVDs, their characteristics, and associated factors.

METHODS

In the year 2015, an Internet cross-sectional health survey was completed by 5931 adults in the general populations of 3 English-speaking countries; 2100 participants were in the United States, Canada, or the United Kingdom. Quota-based sampling was used to generate demographically balanced and population-representative samples. The survey collected data on demographics, health care visits, medications, somatic symptom severity, quality of life, and symptom-based diagnostic criteria for Rome IV FNVDs as well as for irritable bowel syndrome and functional dyspepsia. Subsequent comparisons were made between Rome IV FNVD subjects and individuals without FNVDs (controls).

RESULTS

Overall, 2.2% of the population (n = 131) fulfilled symptom-based diagnostic criteria for Rome IV FNVDs: the United States (3%) had a greater prevalence than Canada (1.9%) or the United Kingdom (1.8%) (P = .02). The prevalence of CNVS was similar among the countries, ranging from 0.8% to 1.2%. However, the prevalence of CVS was higher in the United States (2%) than in Canada (0.7%) or the United Kingdom (1%) (P = .03). The proportion of subjects with CVS taking cannabis did not differ significantly among countries (P = .31), although the 7 cases of cannabinoid hyperemesis syndrome were in the United States. A significantly higher proportion of subjects with CVS reported a compulsive need for hot water bathing to alleviate emetic symptoms than subjects with CNVS (44% vs 19%; P = .03); this behavior was independent of cannabis but augmented by its use. Subjects with FNVDs had significantly greater health impairment and health care utilization than controls. On multivariate analysis, independent factors associated with FNVDs were younger age, increasing somatic symptom severity, lower quality of life, presence of irritable bowel syndrome, and functional dyspepsia. However, on subgroup analysis, somatic symptom severity was associated with CVS but not CNVS, whereas poor quality of life was associated with CNVS but not CVS.

CONCLUSIONS

Based on a cross-sectional health survey of adults in the general populations of 3 English-speaking countries, approximately 2% of subjects meet symptom-based criteria for Rome IV FNVDs and have considerable health impairments. Hot water bathing to alleviate emetic symptoms is reported for all FNVDs, and is perpetuated by cannabis use.

Episodic syndromes of childhood associated with migraine

PURPOSE OF REVIEW

This review covers recent advances in our understanding of episodic syndromes that may be associated with migraine in children and adolescents, as well as what is known about the treatment of these disorders.

RECENT FINDINGS

The episodic syndromes include benign paroxysmal torticollis, benign paroxysmal vertigo, abdominal migraine, and cyclic vomiting syndrome. Infant colic, or excessive crying in an otherwise healthy and well fed infant, may also fit into this category and is included in the appendix section of the most recent edition of the International Classification of Headache Disorders.

SUMMARY

Episodic syndromes are considered to be early life expressions of migraine in the developing brain. Additional research is needed to determine, which acute and preventive treatments are the most effective in managing these disorders.

Cannabis, Cannabinoids, and the Endocannabinoid System-Is there Therapeutic Potential for Inflammatory Bowel Disease?

Cannabis sativa and its extracts have been used for centuries, both medicinally and recreationally. There is accumulating evidence that exogenous cannabis and related cannabinoids improve symptoms associated with inflammatory bowel disease [IBD], such as pain, loss of appetite, and diarrhoea. In vivo, exocannabinoids have been demonstrated to improve colitis, mainly in chemical models. Exocannabinoids signal through the endocannabinoid system, an increasingly understood network of endogenous lipid ligands and their receptors, together with a number of synthetic and degradative enzymes and the resulting products. Modulating the endocannabinoid system using pharmacological receptor agonists, genetic knockout models, or inhibition of degradative enzymes have largely shown improvements in colitis in vivo. Despite these promising experimental results, this has not translated into meaningful benefits for human IBD in the few clinical trials which have been conducted to date, the largest study being limited by poor medication tolerance due to the Δ9-tetrahydrocannabinol component. This review article synthesises the current literature surrounding the modulation of the endocannabinoid system and administration of exocannabinoids in experimental and human IBD. Findings of clinical surveys and studies of cannabis use in IBD are summarised. Discrepancies in the literature are highlighted together with identifying novel areas of interest.

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.

Cannabinoids and gastrointestinal motility: Pharmacology, clinical effects, and potential therapeutics in humans

BACKGROUND

Cannabinoid agents and cannabis are frequently used for relief of diverse gastrointestinal symptoms.

PURPOSE

The objective of this article is to increase the awareness of gastroenterologists to the effects of cannabinoids on gastrointestinal motility, as gastroenterologists are likely to encounter patients who are taking cannabinoids, or those with dysmotility that may be associated with cannabinoid mechanisms. The non-selective cannabinoid agonist, dronabinol, retards gastric emptying and inhibits colonic tone and phasic pressure activity. In addition to the well-recognized manifestations of cannabinoid hyperemesis, cannabinoid mechanisms result in human and animal models of gastrointestinal and colonic dysmotility. Decreased enteric FAAH activity is associated with colonic inertia in slow transit constipation and, conversely, the orphan G protein-coupled receptor, GPR55, is overexpressed in streptozotocin-induced gastroparesis, suggesting it is involved in inhibition of antral motility. Experimental therapies in gastrointestinal motility and functional disorders are focused predominantly on pain relief mediated through cannabinoid 2 receptors or inhibition of DAGLα to normalize colonic transit. In summary, cannabinoid mechanisms and pharmacology are relevant to the current and future practice of clinical gastroenterology.

Pharmacophore modeling for identification of anti-IGF-1R drugs and in-vitro validation of fulvestrant as a potential inhibitor

Insulin-like growth factor 1 receptor (IGF-1R) is an important therapeutic target for breast cancer treatment. The alteration in the IGF-1R associated signaling network due to various genetic and environmental factors leads the system towards metastasis. The pharmacophore modeling and logical approaches have been applied to analyze the behaviour of complex regulatory network involved in breast cancer. A total of 23 inhibitors were selected to generate ligand based pharmacophore using the tool, Molecular Operating Environment (MOE). The best model consisted of three pharmacophore features: aromatic hydrophobic (HyD/Aro), hydrophobic (HyD) and hydrogen bond acceptor (HBA). This model was validated against World drug bank (WDB) database screening to identify 189 hits with the required pharmacophore features and was further screened by using Lipinski positive compounds. Finally, the most effective drug, fulvestrant, was selected. Fulvestrant is a selective estrogen receptor down regulator (SERD). This inhibitor was further studied by using both in-silico and in-vitro approaches that showed the targeted effect of fulvestrant in ER+ MCF-7 cells. Results suggested that fulvestrant has selective cytotoxic effect and a dose dependent response on IRS-1, IGF-1R, PDZK1 and ER-α in MCF-7 cells. PDZK1 can be an important inhibitory target using fulvestrant because it directly regulates IGF-1R.

Cyclic vomiting syndrome: epidemiology, diagnosis, and treatment

Cyclic-vomiting syndrome (CVS) is a chronic functional gastrointestinal disorder characterized by recurrent episodes of nausea and vomiting. Although once thought to be a pediatric disorder, there has been a considerable increase in recognition of CVS in adults. The exact pathogenesis is unknown and several theories have been proposed. Migraine and CVS share a similar pathophysiology as suggested by several studies. Since there are no specific biomarkers available for this disorder, physicians should rely on Rome criteria for the diagnosis. Due to the lack of randomized control trials, the treatment of CVS is primarily empirical.

Cyclic vomiting syndrome is a prevalent and under-recognized condition in the gastroenterology outpatient clinic

BACKGROUND

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder (FGID) characterized by intermittent episodes of nausea and vomiting. Our aim was to report its prevalence and associated features.

METHODS

Data concerning demographics, symptoms, and psychiatric comorbidity were collected. Symptoms compatible with CVS were classified as per Rome III criteria. We recorded whether a diagnosis of CVS was considered in patients after negative investigation. We compared demographics and association with other FGIDs in patients with and without CVS.

KEY RESULTS

920 of 1002 patients provided data. Of the 920 patients, 112 (12.2%) had symptoms compatible with CVS. Thirteen (11.6%) of these had an organic cause for their symptoms, but 99 patients (88.4%) were deemed to have CVS (prevalence=10.8%). Organic causes for symptoms compatible with CVS included gastroparesis, large hiatus hernia, achalasia, and small bowel obstruction. Only 39.4% of patients with CVS were asked about vomiting symptoms at their initial consultation, and a diagnosis of CVS was considered in only four (4.0%) of the 99 patients. CVS was associated with younger age, tobacco smoking, never having married, psychiatric comorbidity, and presence of symptoms compatible with other FGIDs (P≤.01).

CONCLUSIONS AND INFERENCES

Prevalence of CVS in this outpatient gastroenterology adult population was 10.8%. Identified associations included younger age, tobacco smoking, psychiatric comorbidity, and symptoms compatible with other FGIDs. The condition was considered as a possible diagnosis in <5% of patients who met the diagnostic criteria.