Prophylactic Therapy of Cyclic Vomiting Syndrome in Children: Comparison of Amitriptyline and Cyproheptadine: A Randomized Clinical Trial

European Guideline on Chronic Nausea and Vomiting-A UEG and ESNM Consensus for Clinical Management

INTRODUCTION

Chronic nausea and vomiting are symptoms of a wide range of gastrointestinal and non-gastrointestinal conditions. Diagnosis can be challenging and requires a systematic and well-structured approach. If the initial investigation for structural, toxic and metabolic disorders is negative, digestive motility and gut-brain interaction disorders should be assessed. United European Gastroenterology (UEG) and the European Society for Neurogastroenterology and Motility (ESNM) identified the need for an updated, evidence-based clinical guideline for the management of chronic nausea and vomiting.

METHODS

A multidisciplinary team of experts in the field, including European specialists and national societies, participated in the development of the guideline. Relevant questions were addressed through a literature review and statements were developed and voted on according to a Delphi process.

RESULTS

Ninety-eight statements were identified and voted following the Delphi process. Overall agreement was high, although the grade of scientific evidence was low in many areas. Disagreement was more evident for some pharmacological treatment options. A diagnostic algorithm was developed, focussing on the differentiating features between gastrointestinal motility and gut-brain interaction disorders with predominant nausea and vomiting.

CONCLUSION

These guidelines provide an evidence-based framework for the evaluation and treatment of patients with chronic nausea and vomiting.

Prophylactic Cyproheptadine to Control Paroxysmal Hemicrania Attacks: A Preliminary Investigation

Background

Paroxysmal hemicrania (PH) is a severe short-lasting headache usually localized around the eye. It might occur in conjunction with ipsilateral autonomic manifestations of trigeminal nerve stimulation. PH responds well to indomethacin treatment; however, considering the adverse effects of indomethacin, its long-term use is a matter of question and investigations about other prophylactic medications are going on, but they are inconclusive. The current study aims to investigate the efficacy of prophylactic use of cyproheptadine to control PH symptoms.

Materials and Methods

The current clinical trial was conducted on 20 children diagnosed with PH undergoing prophylactic treatment with cyproheptadine syrup at a dosage of 0.2-0.4 mg/kg twice daily for a period of 3 months. The duration, frequency, and severity of headaches were assessed at baseline and then monthly for 3 months.

Results

Significantly shorter duration, less frequency, and less severity of headaches were observed in the postintervention assessments of the patients (P < 0.001). The effect size analysis showed that the greatest effect of the treatment was on the intensity of the headache (effect size: 0.866) and the least effect was on duration of the headache (effect size: 0.775). Drowsiness (5%) and increased appetite (30%) were the only adverse effects of treatment with cyproheptadine.

Conclusion

Findings of this study showed that short-term prophylactic cyproheptadine in divided doses of 0.2-0.4 mg/kg could appropriately improve PH in terms of frequency, duration, and the intensity of the attacks. Nevertheless, further investigations are strongly recommended.

Evidence-based review and frontiers of migraine therapy

BACKGROUND

Cyclic vomiting syndrome (CVS) is identified as one of the "episodic syndromes that may be associated with migraine," along with benign paroxysmal torticollis, benign paroxysmal vertigo, and abdominal migraine. It has been proposed that CVS and migraine may share pathophysiologic mechanisms of hypothalamic activation and altered dopaminergic signaling, and impaired sensorimotor intrinsic connectivity. The past decade has brought groundbreaking advances in the treatment of migraine and other headache disorders. While many of these therapies have yet to be studied in episodic syndromes associated with migraine including CVS and abdominal migraine, the potential shared pathophysiology among these conditions suggests that use of migraine-specific treatments may have a beneficial role even in those for whom headache is not the primary symptom.

PURPOSE

This manuscript highlights newer therapies in migraine. Calcitonin gene-related peptide (CGRP) and its relation to migraine pathophysiology and the therapies that target the CGRP pathway, as well as a 5HT1F receptor agonist and neuromodulation devices used to treat migraine are briefly discussed as they may potentially prove to be useful in the future treatment of CVS.

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.

Treatment Options for Cyclic Vomiting Syndrome: A Real-World, Single-Center Experience with Systematic Literature Review and Meta-Analysis

The optimal therapeutic management of cyclic vomiting syndrome (CVS) remains elusive. The objective of this study was to document our clinical experience in the Pediatric Department of San Marco Hospital and to survey the literature on pediatric CVS treatment, aiming to update the guidance on the most effective treatment strategies for this not-so-uncommon condition. Data from 70 patients with CVS, admitted to our Pediatric Department between September 2011 and December 2021, were aggregated and included in the study. A systematic review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool and the A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) method. Treatment responses, as observed both in the literature and in our own experience, are variable. In our cohort, topiramate demonstrated superiority over other pharmacological treatments, exhibiting an efficacy of 85% in the patients treated. A universally accepted treatment protocol for pediatric CVS has yet to be established. The efficacy of first-line treatments is generally suboptimal, suggesting that topiramate might serve as a safe and effective primary therapeutic option for pediatric CVS.

Pharmacogenomic testing for CYP2C19 and CYP2D6 in cyclic vomiting syndrome

BACKGROUND

Amitriptyline (AT) is recommended as first-line prophylactic therapy in patients with cyclic vomiting syndrome (CVS). However, significant side effects limit its use and dosing is based on trial and error. Though the Clinical Pharmacogenetic Implementation Consortium (CPIC) Guidelines recommend dosing for AT based on CY2D6 and CYP2C19 genotype profile, this is not followed in clinical practice.

METHODS

This pilot study determined CYP2C19 and CYP2D6 genotypes and ascertained its association with adverse drug reactions (ADRs), clinical response, and serum concentration of AT and nortriptyline in a well-characterized cohort of adults with CVS.

KEY RESULTS

Of 46 subjects with CVS, age 33 ± 12 years, 61% female, 85% Caucasian, a third (33%) had normal CYP2C19 metabolizer status, while 4% were poor, and 43% were ultrarapid metabolizers. Most (61%) had normal CYP2D6 genotype while 9% were poor and 2% were ultra-rapid metabolizers. There was no statistically significant association between genotype and ADRs, clinical response or serum drug concentration. There was a trend towards significance between genotype and clinical response, with 64% of responders having normal CYP2D6 metabolism versus 36% of nonresponders (p = 0.06). ADRs were encountered in 46% of patients with 28% discontinuing the medication as a result.

CONCLUSIONS AND INFERENCES

A subset of patients with CVS have dysfunctional alleles of CYP2C19 and CYP2D6. Larger prospective studies to evaluate the clinical impact of pharmacogenomic testing in CVS are needed. This has the potential to optimize clinical management, predict ADRs and allow for personalized therapy.

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.

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.

Psychological and Behavioral Factors Associated with Cyclic Vomiting Syndrome: Case Report

Introduction:Cyclic vomiting syndrome is a disorder of unknown etiology and pathogenesis characterized by recurrent and stereotypical vomiting episodes with varying intervals from baseline or normal health in between. The biopsychosocial model proposes that disease does not result from a single etiology but from systems that interact simultaneously at the cellular, tissue, organismal, interpersonal, and environmental levels. In addition, psychosocial factors have direct and reverse physiological and pathological consequences. Case: In this case report, A 17-year-old boy was consulted to the psychiatry department because of repeated vomiting suspected of psychological factors. The patient was hospitalized due to vomiting. This vomiting has been experienced by the patient since around 2 months before the examination. Patient’s father and stepmother actually really love this patient, but in the patient's perception, the patient's father and mother are less adequate in how to show their affection. The patient realized that his father loved him but felt in some ways, the patient was uncomfortable because he felt that he did not fit his father's mindset. Conclusion:The patient was diagnosed with Psychological and Behavioral Factors Associated with Cyclic Vomiting Syndrome (F54). Pharmacological therapy with 12.5 mg Amytriptiline tablet, 0.5 mg Risperidone tablet, and 5 mg Clobazam tablet every 24 hours orally (evening), while the non-pharmacological therapy given was supportive psychotherapy and psychoeducation to the parent.  

Cyclic Vomiting Syndrome in Pediatric Patients: A Review of Therapeutics

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder that can present quite a challenge to clinicians caring for children with this complex disease. Different therapeutic interventions are recommended for prophylaxis and acute abortive therapy for a CVS attack. The aim of this review is to summarize therapeutic treatment recommendations from the 2008 North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHN) Consensus Statement on the Diagnosis and Management of Cyclic Vomiting Syndrome and discuss studies contemporary to this expert recommendation. After an extensive search of medical databases, 8 studies that evaluated therapeutic treatments for CVS were identified. Amitriptyline and cyproheptadine remain the standard of care for prophylaxis. Nutritional supplements such as carnitine and coenzyme Q10 have shown efficacy in decreasing episodes and severity in small studies with high tolerability among patients. The combination of ondansetron and sumatriptan are recommended for abortion of an acute vomiting episode, but other agents such as aprepitant and sedative agents can be considered when vomiting is refractory to initial treatments.

Migraine and Its Equivalents: What Do They Share? A Narrative Review on Common Pathophysiological Patterns

Migraine is the first in order of frequency of the neurological disorders, affecting both adult and paediatric populations. It is also the first cause of primary headaches in children. Migraine equivalents are periodic disorders that can be associated with migraine or considered as prognostic features of a future migraine manifestation. Despite the mechanisms underlying migraine and its equivalents are not entirely clear, several elements support the hypothesis of common pathophysiological patterns shared by these conditions. The aim of this review is thus to analyze the literature in order to highlight which currently known mechanisms may be common between migraine and its equivalents.

Electrocardiogram Before Tricyclic Antidepressant Use: Minimal Impact in Pediatric Functional Gastrointestinal Disorders

OBJECTIVES

The aim of this study was to determine the effect of electrocardiogram (ECG) findings on the initiation of tricyclic antidepressants (TCAs) for functional gastrointestinal disorders (FGIDs) and to evaluate cardiac outcomes related to low dose TCA use.

METHODS

We performed a retrospective chart review of all pediatric outpatients at a tertiary pediatric hospital with an ECG ordered by a pediatric gastroenterologist when considering initiation of a TCA between January 2011 and February 2018. We collected demographics, previous cardiovascular testing results, TCA dosing, and pertinent outcomes, including cardiology referrals, emergency department, and hospital admissions, and death during the study period. All ECGs were reviewed for corrected QT (QTc) interval, heart rate, and other abnormalities.

RESULTS

Of 233 patients with screening ECGs, most (84.1%) were prescribed a TCA. Functional abdominal pain or dyspepsia account for 82.0% of diagnoses. Initial TCA dosing of amitriptyline varied widely, 10-50 mg/day, and the dose was not associated with QTc intervals. TCAs were not started in only 1.7% (4/233) due to ECG results. A significant ECG abnormality prompting cardiology referral was found in eight (3.4%) with a prolonged QTc interval in one (0.4%). In 10.7% (25/233) of patients, screening ECG was obtained despite available ECG in the chart. No deaths and no emergency department or hospital visits for arrhythmia or drug overdose occurred.

CONCLUSION

Screening ECGs infrequently influence TCA initiation and may lead to increased resource utilization. The overall frequency of cardiology referral due to ECG results is low. Serious adverse cardiac events are unlikely with low dose TCA administration.

Safety of Cyproheptadine, an Orexigenic Drug. Analysis of the French National Pharmacovigilance Data-Base and Systematic Review

Objectives: Cyproheptadine is a first-generation H1-antihistamine drug first that was distributed in the 1960s. While its orexigenic effect was observed early, cyproheptadine is not yet authorized for this indication in all countries today. There is an increasing medical interest and demand for the orexigenic effect of cyproheptadine, especially in children with poor appetite. As cyproheptadine might be evaluated in future clinical trials, we wanted to assess its safety profile. Methods: Using the French national pharmacovigilance database, we retrospectively analyzed all pediatric and adult reports of adverse effects of cyproheptadine recorded since its first distribution in France. Next, we performed a systematic review of the literature of cyproheptadine adverse effects. Results: Since 1985, 93 adverse effects were reported in the French pharmacovigilance database (adults 81.7%, children 18.3%); these were mainly neurological symptoms (n = 38, adults 71%, children 28.9%), and hepatic complications (n = 15, adults 86.7%, children 13.3%). In the literature, the most frequent adverse effect reported was drowsiness in adults or children, and five case reports noted liver complications in adults. We estimated the frequency of hepatic adverse effects at 0.27 to 1.4/1000, regardless of age. Conclusion: Cyproheptadine can be considered a safe drug. Mild neurological effects appear to be frequent, and hepatotoxicity is uncommon to rare. Randomized controlled trials are needed to evaluate the safety and efficacy of cyproheptadine before authorization for appetite stimulation, especially in young children as studies at this age are lacking. Possible hepatic complications should be monitored, as very rare cases of liver failure have been reported.

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.

Management of cyclic vomiting syndrome in adults: Evidence review

BACKGROUND

This evidence review was conducted to inform the accompanying clinical practice guideline on the management of cyclic vomiting syndrome (CVS) in adults.

METHODS

We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework and focused on interventions aimed at prophylactic management and abortive treatment of adults with CVS. Specifically, this evidence review addresses the following clinical questions: (a) Should the following pharmacologic agents be used for prophylaxis of CVS: amitriptyline, topiramate, aprepitant, zonisamide/levetiracetam, or mitochondrial supplements? (b) Should the following pharmacologic agents be used for abortive treatment: triptans or aprepitant?

RESULTS

We found very low-quality evidence to support the use of the following agents for prophylactic and abortive treatment of CVS: amitriptyline, topiramate, aprepitant, zonisamide/levetiracetam, and mitochondrial supplements. We have moderate certainty of evidence for the use of triptans as abortive therapy. We found limited evidence to support the use of ondansetron and the treatment of co-morbid conditions and complementary therapies.

CONCLUSIONS

This evidence review helps inform the accompanying guideline for the management of adults with CVS which is aimed at helping clinicians, patients, and policymakers, and should improve patient outcomes.

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.

Guidelines on management of cyclic vomiting syndrome in adults by the American Neurogastroenterology and Motility Society and the Cyclic Vomiting Syndrome Association

The increasing recognition of cyclic vomiting syndrome (CVS) in adults prompted the development of these evidence-based guidelines on the management of CVS in adults, which was sponsored by the American Neurogastroenterology and Motility Society (ANMS) and the Cyclic Vomiting Syndrome Association (CVSA). GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) framework was used and a professional librarian performed the literature search. The expert committee included the President of the CVSA who brought a patient perspective into the deliberations. The committee makes recommendations for the prophylaxis of CVS, treatment of acute attacks, diagnosis, and overall management of CVS. The committee strongly  recommends that adults with moderate-to-severe CVS receive a tricyclic antidepressant (TCA), such as amitriptyline, as a first-line prophylactic medication and receive topiramate or aprepitant as alternate prophylactic medications. Zonisamide or levetiracetam and mitochondrial supplements (Coenzyme Q10, L-carnitine, and riboflavin) are conditionally recommended as alternate prophylactic medications, either alone or concurrently with other prophylactic medications. For acute attacks, the committee conditionally recommends using serotonin antagonists, such as ondansetron, and/or triptans, such as sumatriptan or aprepitant to abort symptoms. Emergency department treatment is best achieved with the use of an individualized treatment protocol and shared with the care team (example provided). The committee recommended screening and treatment for comorbid conditions such as anxiety, depression, migraine headache, autonomic dysfunction, sleep disorders, and substance use with referral to appropriate allied health services as indicated. Techniques like meditation, relaxation, and biofeedback may be offered as complementary therapy to improve overall well-being and patient care outcomes.

Cyclic vomiting syndrome: diagnostic approach and current management strategies

Cyclic vomiting syndrome (CVS) is a disorder characterized by episodes of nausea and vomiting lasting for 1-5 days followed by asymptomatic periods. The etiology of CVS is unknown, but it shares similar characteristics to migraine headaches. CVS is generally classified as having four phases: prodromal, acute/vomiting/hyperemesis, recovery, and remission/interepisodic. Current management strategies include trigger avoidance, abortive and prophylactic medication therapies, and supportive care. The goal of therapy for the remission phase is prophylaxis of further episodes. Antidepressant, antiepileptic, and antimigraine medications show an overall reduction or remission of CVS symptoms in more than 70% of patients. This article provides a summary of diagnostic strategies and reviews current management strategies for CVS.

Managing cyclic vomiting syndrome in children: beyond the guidelines

Cyclic vomiting syndrome (CVS) in children is characterized by frequent hospitalizations, multiple comorbidities, and poor quality of life. In the absence of robust data, the treatment of CVS remains largely empiric starting with the 2008 NASPGHAN Consensus Statement recommendations of cyproheptadine for children < 5 years of age and amitriptyline for those ≥ 5 years with propranolol serving as the second-line agent. Comprehensive management begins with lifestyle alterations, and extends to medications, supplements, and stress reduction therapies. Standard drug therapy is organized by the four phases of the illness: (1) interictal (preventative medications and mitochondrial supplements), (2) prodromal (abortive agents), (3) vomiting (fluids/energy substrates, antiemetics, analgesics, and sedatives) and (4) recovery (supportive care and nutrition). Because the response to treatment is heterogeneous, clinicians often trial several different preventative strategies including NK1 antagonists, cautious titration of amitriptyline to higher doses, anticonvulsants, Ca²⁺-channel blockers, and other TCA antidepressants. When the child remains refractory to treatment, reconsideration of possible missed diagnoses and further mono- or combination therapy and psychotherapy can be guided by accompanying comorbidities (especially anxiety), specific subphenotype, and when available, genotype. For hospital intervention, IV fluids with 10% dextrose, antiemetics, and analgesics can lessen symptoms while effective sedation in some instances can truncate severe episodes.

CONCLUSION

Although management of CVS remains challenging to the clinician, approaches based upon recent literature and accumulated experience with subgroups of patients has led to improved treatment of the refractory and hospitalized patient. What is Known: • Cyclic vomiting syndrome is a complex disorder that remains challenging to manage. • Previous therapy has been guided by the NASPGHAN Consensus Statement of 2008. What is New: • New prophylactic approaches include NK1 antagonists and higher dosages of amitriptyline. • Strategies based upon comorbidities and subphenotype are helpful in refractory patients.