New Insights into the Mechanism of Action of Viloxazine: Serotonin and Norepinephrine Modulating Properties

Serotonergic Drugs for the Treatment of Attention-Deficit/Hyperactivity Disorder: A Review of Past Development, Pitfalls and Failures, and a Look to the Future

Serotonin has been implicated in the neurobiology of attention-deficit/hyperactivity disorder (ADHD) due to its association with impulsivity, attention, and emotional regulation. Many compounds with serotonergic properties have been evaluated in ADHD, but few have been approved by regulatory authorities. Utilizing a search of public databases, we identified interventions studied in ADHD. Prescribing information and peer-reviewed and gray literature helped us to determine which compounds had an underlying mechanism of action associated with changing serotonin levels. Of the 24 compounds that met the search criteria, 16 had either failed clinical studies in an ADHD population or had been discontinued from future development. The available evidence was assessed to identify the developmental history of drugs with serotonergic activity and the outlook for new ADHD drug candidates targeting serotonin. Several treatment candidates floundered due to an inability to balance effectiveness with safety, underscoring the potential importance of potency, and selectivity. Ongoing drug development includes compounds with multimodal mechanisms of action targeting neurotransmission across serotonin, norepinephrine, and dopamine pathways; it appears likely that treatment which balances competing and complementary monoamine effects may provide improved outcomes for patients. It is hoped that continuing research into ADHD treatment will produce new therapeutic options targeting the serotonergic system, which can positively impact a wide range of symptoms, including mood, anxiety, and sleep as well as attention and hyperactivity.

Current nonstimulant medications for adults with attention-deficit/hyperactivity disorder

INTRODUCTION

Stimulants, including methylphenidate and amphetamines, are the first-line pharmacological treatment of ADHD in adults. However, in patients who do not respond or poorly tolerate stimulants, non-stimulant medications are usually recommended.

AREAS COVERED

The authors provide a narrative review of the literature on non-stimulant treatments for adult ADHD, including controlled and observational clinical studies conducted on adult samples. Atomoxetine has been extensively studied and showed significant efficacy in treating adult ADHD. Issues related to dosing, treatment duration, safety, and use in the case of psychiatric comorbidity are summarized. Among other compounds indicated for ADHD in adults, antidepressants sharing at least a noradrenergic or dopaminergic component, including tricyclic compounds, bupropion, and viloxazine, have shown demonstratable efficacy. Evidence is also available for antihypertensives, particularly guanfacine, as well as memantine, metadoxine, and mood stabilizers, while negative findings have emerged for galantamine, antipsychotics, and cannabinoids.

EXPERT OPINION

While according to clinical guidelines, atomoxetine may serve as the only second-line option in adults with ADHD, several other nonstimulant compounds may be effectively used in order to personalize treatment based on comorbid conditions and ADHD features. Nevertheless, further research is needed to identify and test more personalized treatment strategies for adults with ADHD.

The role of adrenergic neurotransmitter reuptake inhibitors in the ADHD armamentarium

INTRODUCTION

Adrenergic neurotransmitter reuptake inhibitors are gaining attention in treatment for attention-deficit hyperactivity disorder (ADHD). Due to their effects on norepinephrine, dopamine, and serotonin neurotransmission, they benefit both ADHD and comorbid disorders and have some other advantages including longer duration of action and fewer adverse effects compared to stimulants. There is continued interest in these agents with novel mechanisms of action in treatment of ADHD.

AREAS COVERED

The authors conducted a PubMed literature search using the following key words: 'ADHD' AND 'adrenergic reuptake inhibitors' OR 'nonstimulants' OR 'atomoxetine' OR 'Viloxazine' OR 'Dasotraline' OR 'Centanafadine' OR 'PDC-1421' OR 'Reboxetine' OR 'Edivoxetine' OR 'Bupropion' OR 'Venlafaxine' OR 'Duloxetine.' They reviewed FDA fact sheets of available medications for safety/tolerability studies and reviewed published clinical studies of these medications for treatment of ADHD.

EXPERT OPINION

Adrenergic neurotransmitter reuptake inhibitors fit the diverse needs of children and adolescents with ADHD with 1) poor tolerability to stimulants (e.g. due to growth suppression, insomnia, rebound irritability, co-morbid depression, anxiety and tic disorders, substance abuse or diversion concerns), 2) cardiac risks, and/or 3) need for extended duration of action. Their differences in receptor affinities and modulating effects support the unique benefits of individual agents.

Impact of Viloxazine Extended-Release Capsules (Qelbree®) on Select Cytochrome P450 Enzyme Activity and Evaluation of CYP2D6 Genetic Polymorphisms on Viloxazine Pharmacokinetics

BACKGROUND AND OBJECTIVE

Viloxazine extended-release (ER) [Qelbree®] is a nonstimulant attention-deficit/hyperactivity disorder (ADHD) treatment. In vitro studies suggested potential for viloxazine to inhibit cytochrome 450 (CYP) enzymes 1A2, 2B6, 2D6 and 3A4. This clinical study therefore evaluated viloxazine ER effects on index substrates for CYP1A2, 2D6, and 3A4, and secondarily evaluated the impact of CYP2D6 polymorphisms on viloxazine pharmacokinetics.

METHODS

Thirty-seven healthy subjects received a modified Cooperstown cocktail (MCC; caffeine 200 mg, dextromethorphan 30 mg, midazolam 0.025 mg/kg) on Day 1, viloxazine ER 900 mg/day on Days 3-5, and a combination of viloxazine ER 900 mg and MCC on Day 6. Viloxazine ER effects on MCC substrates were evaluated using analysis of variance. The impact of CYP2D6 genetic polymorphisms on steady-state viloxazine plasma concentrations was evaluated using Student's t test assessing pharmacokinetic parameter differences between poor versus extensive metabolizers.

RESULTS

The least squares geometric mean ratio [GMR%] (90% CI) of MCC substrate + viloxazine ER/MCC substrate alone for caffeine maximum concentration (Cmax), area under the plasma concentration-time curve from time 0 to the last quantifiable concentration (AUCt), and area under the plasma concentration-time curve from time 0 extrapolated to infinity (AUC∞) was 99.11 (95.84-102.49), 436.15 (398.87-476.92), and 583.35 (262.41-1296.80), respectively; 150.76 (126.03-180.35), 185.76 (155.01-222.61), and 189.71 (160.37-224.42) for dextromethorphan Cmax, AUCt, and AUC∞, respectively; and 112.81 (104.71-121.54), 167.56 (153.05-183.45), and 168.91 (154.38-184.80) for midazolam Cmax, AUCt, and AUC∞, respectively. At steady state, viloxazine least squares GMR (90% CI) for poor/extensive CYP2D6 metabolizers were Cmax 120.70 (102.33-142.37) and area under the plasme concentration-time curve from time 0 to 24 hours (AUC0-24 125.66 (105.36-149.87)).

CONCLUSION

Viloxazine ER is a strong CYP1A2 inhibitor and a weak CYP2D6 and CYP3A4 inhibitor. CYP2D6 polymorphisms did not meaningfully alter the viloxazine ER pharmacokinetic profile.

From Consensus Statement to Pills to Pixels: New Innovations in Attention-Deficit/Hyperactivity Disorder Care

Objectives: This review aims to present recent innovations and advancements in attention-deficit/hyperactivity disorder (ADHD) care, encompassing international consensus statement, new medication formulations, digital therapeutics, and neurostimulation devices. Methods: A comprehensive literature search of relevant articles published in the past five years was conducted, emphasizing the evidence base, efficacy, safety, and practical implications of these advancements. Results: The World Federation of ADHD Consensus Statement offers an updated diagnostic and treatment framework rooted in global scientific evidence. There are several newer ADHD medication formulations, including a nonstimulant (Viloxazine extended release) and the first transdermal amphetamine patch approved to treat ADHD. These options offer some unique benefits to personalize treatment based on symptom profile, lifestyle, preferences, and response. Digital tools offer additional means to restructure environments for individuals with ADHD, reducing impairment and reliance on others. In addition, digital therapeutics enhance access, affordability, personalization, and feasibility of ADHD care, complementing or augmenting existing interventions. Trigeminal nerve stimulation emerges as a well-tolerated nonpharmacological, device-based treatment for pediatric ADHD, with initial trials indicating effect sizes comparable to nonstimulant medications. Conclusions: These innovations in ADHD care represent clinically significant new treatment options and opportunities for personalized care. Health care professionals should integrate these developments into clinical practice, mindful of individual patient and family needs and preferences. Future research should assess long-term outcomes, cost-effectiveness, and acceptability of these innovations.

Recent advances in pharmacological management of attention-deficit/hyperactivity disorder: moving beyond stimulants

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder characterized by impairing inattention and/or hyperactivity and impulsivity in children and adults. Although medications have been available to treat ADHD symptoms for decades, many are stimulant formulations. Stimulants, such as amphetamine and methylphenidate, are available in more than two dozen formulations, but all have similar adverse effects and carry a risk of misuse and dependence.

AREAS COVERED

In the United States (US), several nonstimulants are available to treat ADHD. Two, including atomoxetine and viloxazine extended-release (ER), are approved by the Food and Drug Administration for the treatment of ADHD in children and adults. Two others, clonidine ER and guanfacine ER, are only approved for children and adolescents in the US. Several other compounds are under investigation. Drugs in Phase 3 trials include centanafadine, solriamfetol, and L-threonic acid magnesium salt. Efficacy and safety data for nonstimulants is presented.

EXPERT OPINION

Although many effective formulations for the treatment of ADHD are available, more than 33% of children and 50% of adults discontinue treatment during the first year. The lack of individual drug response and tolerability are reasons many stop treatment. The development of new nonstimulants may offer hope for patients who need medication alternatives.

Viloxazine extended-release capsules as an emerging treatment for attention-deficit/hyperactivity disorder in children and adolescents

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention and/or hyperactivity and impulsivity. Viloxazine extended-release (ER) capsules (Qelbree®) is a US Food and Drug Administration-approved nonstimulant treatment option for children, adolescents, and adults with ADHD.

AREAS COVERED

This review manuscript summarizes the neurobiology of ADHD and currently available treatment options before discussing viloxazine pharmacology, efficacy, safety, and tolerability data from phase II and III trials in children and adolescents (6-17 years old). Viloxazine clinical efficacy has also been further demonstrated by post hoc analyses of pediatric clinical trial results.

EXPERT OPINION

Current stimulant and nonstimulant treatments for ADHD may be suboptimal given low response rates and that tolerability issues are frequently experienced. Preclinical and clinical evidence has implicated both the role of catecholamine and serotonin signaling in the pathophysiology of ADHD and the pharmacologic effect of viloxazine on these critical neurotransmitter systems. With a relatively rapid onset of action, sustained symptom improvement, and clinical benefit in ADHD-associated impairments (functional and social), viloxazine ER represents a novel and emerging ADHD treatment option.

Viloxazine Increases Extracellular Concentrations of Norepinephrine, Dopamine, and Serotonin in the Rat Prefrontal Cortex at Doses Relevant for the Treatment of Attention-Deficit/Hyperactivity Disorder

Background

Viloxazine ER (viloxazine extended-release capsules; Qelbree®), a nonstimulant attention-deficit/hyperactivity disorder (ADHD) treatment, has known activity as a norepinephrine (NE) transporter (NET) inhibitor. In vitro studies have also shown direct pharmacological effects on specific serotonin (5-HT) receptors, but not on the serotonin transporter (SERT). An in vivo microdialysis study in rats showed viloxazine (50 mg/kg i.p.) increased extracellular 5-HT, NE, and dopamine (DA) in the prefrontal cortex (PFC), a key brain region in ADHD pathology. This study evaluated whether these effects occur at clinically relevant concentrations.

Methods

Microdialysis experiments were conducted in freely-moving, Sprague-Dawley rats (males, 8 weeks). Viloxazine (1, 3, 10, 30 mg/kg) was administered intraperitoneally to establish the dose range in rats at which viloxazine plasma concentrations aligned with those of individuals with ADHD administered therapeutic doses of viloxazine ER. Concentrations of unbound viloxazine, NE, 5-HT, DA, and NE and 5-HT metabolites (3,5-dihydroxyphenylglycol [DHPG] and 5-hydroxyindoleacetic acid [5-HIAA]) were measured in PFC interstitial fluid. After identifying a therapeutically relevant dose (30 mg/kg), the experiment was repeated using 30 and 50 mg/kg viloxazine (as 50 mg/kg increased NE, 5-HT, and DA in prior studies).

Results

Viloxazine unbound (free drug) plasma concentrations in rats at 30 mg/kg were comparable to free drug concentrations in individuals with ADHD taking clinically effective doses (based on validated population PK models). Viloxazine 30 mg/kg significantly increased extracellular NE, 5-HT, and DA PFC levels compared to vehicle. Concomitant decreases in DHPG, but not 5-HIAA, support the inhibitory effect of viloxazine on NET but not SERT.

Conclusion

At clinically relevant concentrations, viloxazine increases PFC NE, DA, and 5-HT. Prefrontal augmentation of 5-HT does not appear to result from 5-HT reuptake inhibition but may be related to activation of 5-HT neurons. The potential therapeutic role of serotonergic effects in ADHD treatment merits further exploration.

Adrenoceptors: A Focus on Psychiatric Disorders and Their Treatments

Research into the involvement of adrenoceptor subtypes in the cause(s) of psychiatric disorders is particularly challenging. This is partly because of difficulties in developing animal models that recapitulate the human condition but also because no evidence for any causal links has emerged from studies of patients. These, and other obstacles, are outlined in this chapter. Nevertheless, many drugs that are used to treat psychiatric disorders bind to adrenoceptors to some extent. Direct or indirect modulation of the function of specific adrenoceptor subtypes mediates all or part of the therapeutic actions of drugs in various psychiatric disorders. On the other hand, interactions with central or peripheral adrenoceptors can also explain their side effects. This chapter discusses both aspects of the field, focusing on disorders that are prevalent: depression, schizophrenia, anxiety, attention-deficit hyperactivity disorder, binge-eating disorder, and substance use disorder. In so doing, we highlight some unanswered questions that need to be resolved before it will be feasible to explain how changes in the function of any adrenoceptor subtype affect mood and behavior in humans and other animals.

Extended-Release Viloxazine for the Treatment of Attention-Deficit Hyperactivity Disorder in School-Age Children and Adolescents

OBJECTIVE

To describe the efficacy and safety of extended-release viloxazine (viloxazine ER; Qelbree) for the treatment of attention-deficit hyperactivity disorder (ADHD) in school-age children and adolescents (6-17 years).

DATA SOURCES

A literature search was conducted with PubMed using the following terms: viloxazine and ADHD (August 1, 2017 to February 1, 2023).

STUDY SELECTION AND DATA EXTRACTION

All relevant English-language articles examining the efficacy and safety of viloxazine ER were considered for inclusion.

DATA SYNTHESIS

Phase III studies reported significant improvement in ADHD symptoms after viloxazine ER treatment in both school-age children (100 mg/d, P = 0.0004 and 200 mg/d, P < 0.0001; NCT03247530) and adolescents (200 mg/d, P = 0.0232; 400 mg/d, P = 0.0091; NCT03247517) compared with placebo. Common adverse effects associated with viloxazine ER included somnolence, fatigue, irritability, decreased appetite, and headache. Together, the studies demonstrated the efficacy and safety of viloxazine ER in patients with ADHD.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON WITH EXISTING DRUGS

Viloxazine ER is a serotonin-norepinephrine modulator, which is administered once daily orally. It is classified as a nonstimulant medication, which can be used in patients with ADHD who do not respond to or cannot tolerate stimulant medications. Even though atomoxetine and viloxazine ER have not been directly compared, clinical studies have suggested that viloxazine ER has a faster onset of action (~1-2 weeks) compared with atomoxetine (~4 weeks). Like atomoxetine, viloxazine ER carries a boxed warning for suicidal ideation and/or behavior.

CONCLUSION

Viloxazine ER is a useful addition to other nonstimulant medications available to treat patients with ADHD.

Efficacy and Safety of SPN-812 (Extended-Release Viloxazine) in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis

BACKGROUND

SPN-812 has been approved for attention-deficit/hyperactivity disorder (ADHD) treatment in children and adolescents.

OBJECTIVE

We aimed to analyze the efficacy and safety of different doses of SPN-812 for ADHD pediatric patients of different ages, verify its clinical efficacy, and evaluate its safety.

METHODS

Up until 30 August 2023, randomized controlled trials (RCTs) were searched in EMBASE, MEDLINE, the Cochrane Library, and clinicaltrials.gov to evaluate different doses of SPN-812 and a placebo.

RESULTS

We pooled 1619 patients from five RCTs with a duration of 6-8 weeks. Patients (6-17 years old) in SPN-812 (100, 200, and 400 mg/d) groups were superior to the control group in all efficacy outcomes with lower attention-deficit/hyperactivity disorder rating scale-5 (ADHD-RS-5), Conners 3-parent short form composite T score (Conners 3-PS), Weiss functional impairment rating scale-parent (WFIRS-P), and increased clinical global impression-improvement (CGI-I) score (both p < 0.05). At the same time, only SPN-812 300 mg/d did not show a significantly high risk of the adverse events (AEs) such as somnolence and decreased appetite (p = 0.09). There was no significant difference between placebo and SPN-812 groups (100, 200, and 400 mg/d) in serious adverse events (SAEs) such as syncope. The subgroup analyses showed that, both in children and adolescents subgroups, SPN-812 showed better efficacy than the placebo. The two age subgroups showed a significantly higher risk of AEs and an insignificant risk of SAEs than the placebo.

CONCLUSION

At present, SPN-812 (100, 200, and 400 mg/d) is superior to the corresponding control in efficacy measures. However, the safety problem cannot be ignored.

Neuron-Specific Enolase (NSE) as a Biomarker for Autistic Spectrum Disease (ASD)

Autistic spectrum disease (ASD) is an increasingly common diagnosis nowadays with a prevalence of 1-2% in most countries. Its complex causality-a combination of genetic, immune, metabolic, and environmental factors-is translated into pleiomorphic developmental disorders of various severity, which have two main aspects in common: repetitive, restrictive behaviors and difficulties in social interaction varying from awkward habits and verbalization to a complete lack of interest for the outside world. The wide variety of ASD causes also makes it very difficult to find a common denominator-a disease biomarker and medication-and currently, there is no commonly used diagnostic and therapeutic strategy besides clinical evaluation and psychotherapy. In the CORDUS clinical study, we have administered autologous cord blood to ASD kids who had little or no improvement after other treatments and searched for a biomarker which could help predict the degree of improvement in each patient. We have found that the neuron-specific enolase (NSE) was elevated above the normal clinical range (less than 16.3 ng/mL) in the vast majority of ASD kids tested in our study (40 of 41, or 97.5%). This finding opens up a new direction for diagnostic confirmation, dynamic evaluation, and therapeutic intervention for ASD kids.

Extended-Release Viloxazine Compared with Atomoxetine for Attention Deficit Hyperactivity Disorder

BACKGROUND AND OBJECTIVE

In our outpatient pediatric and adult psychiatry centers, we reserve psychostimulants for predominantly inattentive attention deficit hyperactivity disorder (ADHD) due to the potential for appetite and growth suppression, insomnia, wear off, exacerbation of mood, anxiety, and tics, or misuse. We utilize extended-release (ER) alpha-2 agonists primarily for hyperactivity/impulsivity but find them less effective for inattention, and they can cause sedation and hypotension. Oftentimes, we need to combine an alpha-2 agonist for behavior with psychostimulants for inattention. We employ atomoxetine or viloxazine ER (VER) for combined ADHD. However, our patients' insurers mandate a trial of generic atomoxetine prior to covering branded VER. The objective of this study was to determine whether pediatric and adult patients taking atomoxetine for DSM-5-TR ADHD combined type would experience improvement in ADHD symptoms following voluntary, open-label switch to VER.

METHODS

50 patients (35 children) received mean doses of atomoxetine 60 mg (25-100 mg once daily) followed by VER 300 mg (100-600 mg once daily) after a 5-day atomoxetine washout. Both atomoxetine and VER were flexibly titrated according to US Food and Drug Administration (FDA) guidelines. The pediatric ADHD-Rating Scale-5 (ADHD-RS-5) and the Adult Investigator Symptom Rating Scale (AISRS) were completed prior to starting atomoxetine, and 4 weeks after treatment with atomoxetine or upon earlier response or discontinuation due to side effects, whichever occurred first; the same protocol was used after treatment with VER. We conducted a blinded, de-identified, retrospective review of charts from these 50 patients in the regular course of outpatient practice. Statistical analysis was performed using a within-subject, 2-tailed t-test with significance level of p < 0.05.

RESULTS

From the baseline total ADHD-RS-5 mean score (40.3 ± 10.3), improvements were greater on VER (13.9 ± 10.2) than atomoxetine (33.1 ± 12.1; t = - 10.12, p < 0.00001) in inattention (t = - 8.57, p < 0.00001) and in hyperactivity/impulsivity (t = - 9.87, p < 0.00001). From the baseline total AISRS mean score (37.3 ± 11.8), improvements were greater on VER (11.9 ± 9.4) than atomoxetine (28.8 ± 14.9; t = - 4.18, p = 0.0009) in inattention (t = - 3.50, p < 0.004) and in hyperactivity/impulsivity (t = - 3.90, p < 0.002). Of patients on VER, 86% reported positive response by 2 weeks versus 14% on atomoxetine. A total of 36% discontinued atomoxetine for side effects, including gastrointestinal (GI) upset (6 patients), irritability (6), fatigue (5), and insomnia (1), versus 4% who discontinued VER due to fatigue. A total of 96% preferred VER over atomoxetine, with 85% (22 out of 26) choosing to taper psychostimulants following stabilization on VER.

CONCLUSIONS

Pediatric and adult ADHD patients who have experienced less than optimal response to atomoxetine demonstrate rapid improvement in inattention and in hyperactivity/impulsivity with greater tolerability on extended-release viloxazine.

An updated safety review of the current drugs for managing ADHD in children

INTRODUCTION

Attention-Deficit/Hyperactivity Disorder (ADHD) is a highly prevalent condition that causes persistent problems with attention and/or hyperactivity-impulsivity and often results in significant impairment when left untreated. Medications for this disorder continue to evolve and provide new treatment options. Ongoing review of related medication safety and tolerability remains an important task for prescribers.

AREAS COVERED

This manuscript provides an updated safety review of medications used to treat ADHD in children and adolescents. PubMed and OneSearch online databases were utilized to search for literature relevant to the topic of ADHD medications and safety. Clinical trials of medications used to treat ADHD, systematic reviews and meta-analyses, and articles covering specific safety issues (adverse or unfavorable events) such as cardiovascular effects, seizures, impact on growth, depression, suicidal ideation, substance use disorders, psychosis, and tics are described.

EXPERT OPINION

Available pharmacologic treatments for ADHD have favorable efficacy, safety and tolerability and allow many patients to achieve significant improvement of their symptoms. Despite the availability of multiple stimulant and non-stimulant formulations, some individuals with ADHD may not tolerate available medications or attain satisfactory improvement. To satisfy unmet clinical needs, ADHD pharmaceutical research with stimulant and nonstimulant formulations targeting dopamine, norepinephrine, and novel receptors is ongoing.

Viloxazine extended-release capsules for the treatment of attention-deficit/ hyperactivity disorder in adult patients

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder with symptoms that may persist in up to 90% of adults diagnosed during childhood and continue to cause significant impairment throughout the lifespan. In the United States (US), amphetamine and methylphenidate formulations have been available to treat ADHD for several decades. Only one nonstimulant, atomoxetine, was available for the treatment of ADHD in adults until recently. In April 2022, a second nonstimulant, viloxazine extended-release (VLX-ER), became available in the US for the treatment of adult ADHD. Efficacy was previously established in placebo-controlled trials in children and adolescents.

AREAS COVERED

VLX-ER is a norepinephrine reuptake inhibitor with serotonin activity. The efficacy in adults, adverse event profile, pharmacokinetics, drug-drug interactions, and metabolism of VLX-ER are reviewed.

EXPERT OPINION

Despite the availability of effective pharmacological treatments for ADHD, many patients discontinue treatment in less than 1 year. Stimulants are effective in more than 80% of patients; however, some may have difficulty tolerating them. Although there were no head-to-head studies, the effect size of VLX-ER in an adult efficacy trial was lower than has been shown for stimulants. Nevertheless, the approval of VLX-ER adds another effective ADHD treatment option for adults.

Pharmacologic Management of Cognitive Disengagement Syndrome (CDS) and Implications for Attention-Deficit/Hyperactivity Disorder (ADHD) Treatment: Emerging Treatments and Recommendations for Future Research

Although the study of cognitive disengagement syndrome (CDS; previously called sluggish cognitive tempo) first emerged in the 1980s, very little is known about treating CDS or its impact on evidence-based interventions for attention-deficit/hyperactivity disorder (ADHD) with which it frequently co-occurs. The objective of this leading article was to investigate the existing evidence on medication treatment and CDS, including studies that have examined CDS response to medication and CDS as a moderator of ADHD treatment response. A total of seven studies were identified. At present, the limited existing literature suggests that psychostimulants such as methylphenidate and lisdexamfetamine, as well as atomoxetine, may improve CDS symptoms, although replication and research on related medications is needed. However, there are indications that CDS symptoms may predict a reduced response to methylphenidate in children with ADHD. Although untested, research on the neurobiological, neuropsychological, and behavioral correlates of CDS point to a possible benefit of other ADHD medications (e.g., guanfacine), medications that treat narcolepsy (e.g., modafinil), and medications traditionally used to treat depression and anxiety (e.g., viloxazine, bupropion, fluvoxamine), some of which have also recently been used in ADHD management. The article concludes with recommendations for future research on pharmacologic treatment and CDS.

Annual Research Review: Perspectives on progress in ADHD science - from characterization to cause

The science of attention-deficit/hyperactivity disorder (ADHD) is motivated by a translational goal - the discovery and exploitation of knowledge about the nature of ADHD to the benefit of those individuals whose lives it affects. Over the past fifty years, scientific research has made enormous strides in characterizing the ADHD condition and in understanding its correlates and causes. However, the translation of these scientific insights into clinical benefits has been limited. In this review, we provide a selective and focused survey of the scientific field of ADHD, providing our personal perspectives on what constitutes the scientific consensus, important new leads to be highlighted, and the key outstanding questions to be addressed going forward. We cover two broad domains - clinical characterization and, risk factors, causal processes and neuro-biological pathways. Part one focuses on the developmental course of ADHD, co-occurring characteristics and conditions, and the functional impact of living with ADHD - including impairment, quality of life, and stigma. In part two, we explore genetic and environmental influences and putative mediating brain processes. In the final section, we reflect on the future of the ADHD construct in the light of cross-cutting scientific themes and recent conceptual reformulations that cast ADHD traits as part of a broader spectrum of neurodivergence.

Considerations when selecting an antidepressant: a narrative review for primary care providers treating adults with depression

Major depressive disorder (MDD) is a debilitating mental disorder that can be treated with a number of different antidepressant therapies, each with its own unique prescribing considerations. Complicating the selection of an appropriate antidepressant for adults with MDD is the heterogeneity of clinical profiles and depression subtypes. Additionally, patient comorbidities, preferences, and likelihood of adhering to treatment must all be considered when selecting an appropriate therapy. With the majority of prescriptions being written by primary care practitioners, it is appropriate to review the unique characteristics of all available antidepressants, including safety considerations. Prior to initiating antidepressant treatment and when patients do not respond adequately to initial therapy and/or exhibit any hypomanic or manic symptoms, bipolar disorder must be ruled out, and evaluation for psychiatric comorbidities must be considered as well. Patients with an inadequate response may then require a treatment switch to another drug with a different mechanism of action, combination, or augmentation strategy. In this narrative review, we propose that careful selection of the most appropriate antidepressant for adult patients with MDD based on their clinical profile and comorbidities is vital for initial treatment selection.Strategies must be considered for addressing partial and inadequate responses as well to help patients achieve full remission and sustained functional recovery. This review also highlights data for MDD clinical outcomes for which gaps in the literature have been identified, including the effects of antidepressants on functional outcomes, sleep disturbances, emotional and cognitive blunting, anxiety, and residual symptoms of depression.

Epilepsy and Attention Deficit Hyperactivity Disorder: Connection, Chance, and Challenges

Comorbidities are common in children with epilepsy, with nearly half of the patients having at least one comorbidity. Attention deficit hyperactivity disorder (ADHD) is a psychiatric disorder characterized by hyperactivity and inattentiveness level disproportional to the child’s developmental stage. The burden of ADHD in children with epilepsy is high and can adversely affect the patients’ clinical outcomes, psychosocial aspects, and quality of life. Several hypotheses were proposed to explain the high burden of ADHD in childhood epilepsy; the well-established bidirectional connection and shared genetic/non-genetic factors between epilepsy and comorbid ADHD largely rule out the possibility of a chance in this association. Stimulants are effective in children with comorbid ADHD, and the current body of evidence supports their safety within the approved dose. Nonetheless, safety data should be further studied in randomized, double-blinded, placebo-controlled trials. Comorbid ADHD is still under-recognized in clinical practice. Early identification and management of comorbid ADHD are crucial to optimize the prognosis and reduce the risk of adverse long-term neurodevelopmental outcomes. The identification of the shared genetic background of epilepsy and ADHD can open the gate for tailoring treatment options for these patients through precision medicine.

A post hoc analysis of the effect of viloxazine extended-release capsules on learning and school problems in children and adolescents with attention-deficit/hyperactivity disorder

Improvement in attention-deficit/hyperactivity disorder (ADHD) symptoms vs. placebo was reported in a series of pediatric clinical trials of viloxazine extended-release capsules (viloxazine ER; Qelbree™). This post hoc analysis of those studies evaluated the effect of viloxazine ER on learning and school problems (LSPs). We used data from four Phase 3 placebo-controlled trials of 100-600 mg/day viloxazine ER (N = 1354; 6-17 years of age). LSPs were evaluated using the School domain of the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P-S) and the Learning Problems content scale of the Conners 3rd Edition-Parent Short Form (C3PS-LP) at baseline and end of study (≥ Week 6). ADHD symptoms were assessed weekly using the ADHD Rating Scale 5th Edition. The analyses were performed using the general linear mixed model with participant as a random effect. The responder analyses were performed using the Chi-square test. Viloxazine ER demonstrated significantly greater improvements in WFIRS-P-S (p < 0.0001) and C3PS-LP (p = 0.0113) scores vs. placebo. The response rate for the WFIRS-P-S was significantly greater for viloxazine ER vs. placebo (p = 0.001), and the number needed to treat (NNT) was 10.3 (effect size 0.7). Conversely, response rates for C3PS-LP did not differ between groups (p = 0.9069). In addition to ADHD symptoms improvement demonstrated in previous studies, viloxazine ER significantly reduced LSPs in pediatric subjects with ADHD. The responder analyses and NNT estimates indicate that a substantial number of children and adolescents with ADHD treated with viloxazine ER improved in clinically assessed LSPs.

ADHD-A Clinician's Bird's Eye View of Current Status and New Vistas!

Objectives

Literature on ADHD has taken long strides recently as heaps of new data are pouring in through countless papers. Here, authors try to outline changing paradigms in ADHD practice. DSM-5 changes regarding the typology and diagnostic criteria are highlighted. Overview of co-morbidities, associations, developmental trajectories, and syndromic continuity across lifespan is outlined. Recent insights into aetiology and diagnostic tools are briefly discussed. New medications in the pipeline are also described.

Methods

EMBASE, Ovid MEDLINE, PubMed, Scopus, Web of Science, and Cochrane Database of Systemic Reviews were searched for all relevant updates in ADHD literature as of June, 2022.

Results

DSM-5 brought about changes to the diagnostic criteria of ADHD. These included replacing types with presentations, pushing age to 12, and, incorporating adult diagnostic criteria. In the same vein, DSM-5 allows now for diagnosing concurrent ADHD and ASD. Associations of ADHD to allergy, obesity, sleep disorders, and, epilepsy have been demonstrated in recent literature. Neurocircuity underlying ADHD has been extended beyond frontal-striatal to include CTC as well as DMN accounting for ADHD heterogeneity. NEBA was FDA-approved to differentiate ADHD from hyperkinetic ID. Atypical antipsychotics use to address behavioural facets in ADHD is on the rise with no solid evidence-base. α-2 agonists are FDA-approved as monotherapy or adjunctive to stimulants. Pharmacogenetic testing is readily available for ADHD. Different formulations of stimulants abound on the market widening clinicians' repertoire. Stimulant-related exacerbation of anxiety and tics were challenged in recent studies. Drugs for ADHD in the pipeline include-dasotraline, armodafinil, tipepidine, edivoxetine, metadoxine, and memantine.

Conclusions

Literature on ADHD keeps expanding towards advancing our understanding of the complex and heterogeneous intricacies of this commonplace neurodevelopmental disorder and hence informing better decisions on how best to manage its diverse cognitive, behavioural, social and medical facets.

Response of peer relations and social activities to treatment with viloxazine extended-release capsules (Qelbree® ): A post hoc analysis of four randomized clinical trials of children and adolescents with attention-deficit/hyperactivity disorder

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is associated with impairments related to peer relations (PR) and social activities (SA). The objective of this post hoc analysis was to assess the degree to which viloxazine extended-release (viloxazine ER; viloxazine extended-release capsules; Qelbree^® ) improves clinical assessments of PR and SA in children and adolescents with ADHD.

METHODS

Data were used from four Phase III placebo-controlled trials of 100 to 600 mg/day of viloxazine ER (N = 1354; 6-17 years of age). PR and SA were measured with the Peer Relations content scale of the Conners 3rd Edition Parent Short Form's Peer Relation content scale (C3PS-PR) and the Social Activities domain of the Weiss Functional Impairment Rating Scale-Parent Report's (WFIRS-P-SA) at baseline and end of study. ADHD symptoms were assessed weekly with the ADHD Rating Scale, 5th Edition. The analyses relied on the general linear mixed model with the subject as a random effect.

RESULTS

Improvement in C3PS-PR (p = .0035) and WFIRS-P-SA (p = .0029) scores were significantly greater in subjects treated with viloxazine ER compared with placebo. When using measures of clinically meaningful response, the C3PS-PR responder rate was significantly higher for viloxazine ER (19.2%) compared with placebo (14.1%) and the difference was statistically significant (p = .0311); the Number Needed to Treat (NNT) was 19.6. The WFIRS-P-SA responder rate was significantly higher for viloxazine ER (43.2%) compared with placebo (28.5%) and the difference was statistically significant (p < .0001); the NNT was 6.8. The standardized mean difference effect size for both PR and SA was 0.09.

CONCLUSIONS

Viloxazine ER significantly reduces the impairment of PR and SA in children and adolescents with ADHD. Although its effects on PR and SA are modest, many ADHD patients can be expected to achieve clinically meaningful improvements in PR and SA with viloxazine ER treatment for longer than 6 weeks.

Association between ADHD and vision problems. A systematic review and meta-analysis

AIM

To conduct the first systematic review and meta-analysis assessing whether attention-deficit/hyperactivity disorder (ADHD) is associated with disorders of the eye, and/or altered measures of visual function.

METHOD

Based on a pre-registered protocol (PROSPERO: CRD42021256352), we searched PubMed, Web of Knowledge/Science, Ovid Medline, Embase and APA PsycINFO up to 16th November 2021, with no language/type of document restrictions. We included observational studies reporting at least one measure of vision in people of any age meeting DSM/ICD criteria for ADHD and in people without ADHD; or the prevalence of ADHD in people with and without vision disorders. Study quality was assessed with the Appraisal tool for Cross-Sectional Studies (AXIS). Random effects meta-analyses were used for data synthesis.

RESULTS

We included 42 studies in the narrative synthesis and 35 studies in the meta-analyses (3,250,905 participants). We found meta-analytic evidence of increased risk of astigmatism (OR = 1.79 [CI: 1.50, 2.14]), hyperopia and hypermetropia (OR = 1.79 [CI: 1.66, 1.94]), strabismus (OR = 1.93 [CI: 1.75, 2.12]), unspecified vision problems (OR = 1.94 [CI: 1.38, 2.73]) and reduced near point of convergence (OR = 5.02 [CI: 1.78, 14.11]); increased lag (Hedge's g = 0.63 [CI: 0.30, 0.96]) and variability (Hedge's g = 0.40 [CI: 0.17, 0.64]) of the accommodative response; and increased self-reported vision problems (Hedge's g = 0.63 [CI: 0.44, 0.82]) in people with ADHD compared to those without ADHD (with no significant heterogeneity). We also found meta-analytic evidence of no differences between people with and without ADHD on retinal nerve fiber layer thickness (Hedge's g = -0.19 [CI: -0.41, 0.02]) and refractive error (Hedge's g = 0.08 [CI: -0.26, 0.42]) (with no significant heterogeneity).

DISCUSSION

ADHD is associated with some self-reported and objectively ascertained functional vision problems, but not with structural alterations of the eye. Further studies should clarify the causal relationship, if any, between ADHD and problems of vision.

TRIAL REGISTRATION

PROSPERO registration: CRD42021256352.

Treatment of ADHD: Drugs, psychological therapies, devices, complementary and alternative methods as well as the trends in clinical trials

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders having a high influence on social interactions. The number of approved treatments and clinical trials for ADHD have increased markedly during the recent decade. This analytical review provides a quantitative overview of the existing pharmacological and non-pharmacological methods of ADHD treatments investigated in clinical trials during 1999-2021. A total of 695 interventional trials were manually assessed from clinicaltrial.gov with the search term « ADHD», and trial data has been used for analysis. A clear majority of the studies investigated non-pharmacological therapies (∼80%), including many behavioral options, such as social skills training, sleep and physical activity interventions, meditation and hypnotherapy. Devices, complementary and other alternative methods of ADHD treatment are also gaining attention. The pharmacological group accounts for ∼20% of all the studies. The most common drug classes include central nervous system stimulants (e.g., methylphenidate hydrochloride, lisdexamfetamine dimesylate, amphetamine sulfate, mixed amphetamine salts, a combination of dexmethylphenidate hydrochloride and serdexmethylphenidate chloride), selective noradrenaline reuptake inhibitors (atomoxetine, viloxazine), and alpha2 adrenergic receptor agonists (guanfacine hydrochloride, clonidine hydrochloride). Several studies investigated antidepressants (e.g., bupropion hydrochloride, vortioxetine), and atypical antipsychotics (e.g., quetiapine, aripiprazole) but these are yet not approved by the FDA for ADHD treatment. We discuss the quantitative trends in clinical trials and provide an overview of the new drug agents and non-pharmacological therapies, drug targets, and novel treatment options.

The role of placebo response in the efficacy outcome assessment in viloxazine extended-release pivotal trials in paediatric subjects with attention-deficit/hyperactivity disorder

AIMS

Four Phase 3 studies evaluated efficacy and safety of viloxazine extended-release in the treatment of attention-deficit/hyperactivity disorder (ADHD). The primary efficacy objective-change from baseline in ADHD Rating Scale-5 (ADHD-RS-5) Total score at end of study (EOS)-was not met in one of the studies (812P304). A band-pass analysis was performed to evaluate the impact of placebo response on the results.

METHODS

The distribution of placebo response at EOS of each trial was evaluated. The 2.5^th and 97.5^th percentiles of the distribution of ADHD-RS-5 Total score were used as boundaries for the band-pass analysis. An independent mixed model for repeated measures analysis was conducted for each trial using all eligible data (active and placebo) from the total and band-pass filtered populations.

RESULTS

The 2.5^th and 97.5^th percentiles at EOS were 3.5 and 53.5, respectively. Application of the band-pass filter (filtering out all subjects [active, n = 305 (32.1%) and placebo, n = 134 (33.5%)] of clinical sites with placebo scores <3.5 or >53.5) revealed statistically significant improvement at the primary endpoint (600-mg/d viloxazine ER vs. placebo) in Study 812P304 (mean [confidence interval] = 4.9537 [0.5405-9.3669]), previously masked by a high placebo response (mean [confidence interval] = 3.5756 [-0.3332-7.4844]). The outcome of the analysis indicated that the impact of the band-pass adjustment is greater when placebo response is higher.

CONCLUSION

This analysis indicated that a higher placebo response in Study 812P304 confounded the assessment of treatment effect. Application of the band-pass methodology confirmed the positive results of the 3 prior studies and the signal detection confounder in the fourth study.

Viloxazine for the Treatment of Attention Deficit Hyperactivity Disorder

Purpose of Review

Attention deficit hyperactivity disorder (ADHD) is a widely diagnosed neurodevelopmental disorder giving rise to symptoms of hyperactivity, impulsivity, and inattentiveness that can impair daily functioning. Stimulants, such as methylphenidate and amphetamines, are the mainstay of treatment for ADHD. However, nonstimulant drugs such as viloxazine, atomoxetine, guanfacine, and clonidine are becoming more popular due to minimal adverse effects when compared to stimulants.

Recent Findings

Viloxazine is a selective norepinephrine reuptake inhibitor (NRI) originally used to treat depression in adults with activity in both the noradrenergic as well as serotonergic pathways. Studies have demonstrated its efficacy for its use in the treatment of ADHD. Unlike stimulants, viloxazine has a decreased chance of substance abuse, drug dependance, and withdrawal symptoms upon the cessation of therapy. Additionally, dopamine levels in the nucleus accumbens after treatment with viloxazine are elevated considerably less in comparison with traditional stimulant ADHD treatments. Viloxazine provides an alternative, nonstimulant approach to treating ADHD.

Summary

Viloxazine is a recently approved, non-stimulant medication functions by inhibiting the uptake of norepinephrine which has been seen to be decreased in patients with ADHD. When patients do not respond to first-line stimulants, cannot tolerate the side effects, or have contraindications to stimulants, viloxazine may be a nonstimulant option offering patients an increasing arsenal of medications to treat ADHD.

Convergence mechanism of mindfulness intervention in treating attention deficit hyperactivity disorder: Clues from current evidence

This paper reviews the underlying evidence for various aspects of the convergence mechanism of mindfulness intervention in attention deficit hyperactivity disorder (ADHD). There may be compatibility among various ADHD remission models and the therapeutic mechanism of mindfulness intervention in ADHD may be mainly via the convergence mechanism. However, neuroimaging-based analysis of the mechanisms of mindfulness intervention in treating ADHD is lacking. Differences in the efficacy of various subtypes of mindfulness intervention, and corresponding specific imaging changes need further investigation. Future research may focus on the neuroimaging features of specific mindfulness intervention subtypes.

A systematic review of the use of atomoxetine for management of comorbid anxiety disorders in children and adolescents with attention-deficit hyperactivity disorder

BACKGROUND

Anxiety disorders are among the most common comorbid mental disorders in children and adolescents with attention-deficit hyperactivity disorder (ADHD). While the role of atomoxetine, a non-stimulant medication, is well-established in the management of ADHD symptoms since two decades, there is a dearth of evidence regarding its efficacy in the management of anxiety disorders in children and adolescents with ADHD.

AIMS

We aimed to provide insights into (1) the comparative efficacy of atomoxetine in children and adolescents with comorbid ADHD and anxiety disorders, (2) change in severity of anxiety symptoms based on patients', parents', and clinicians' ratings, (3) tolerability and side effects.

METHODS

We searched PubMed, EMBASE, and PsycINFO for clinical trials that addressed the efficacy of atomoxetine for anxiety symptoms in children and adolescents with ADHD. All published literature was systematically reviewed.

RESULTS

We included four studies, out of which two specifically addressed comorbid ADHD and anxiety disorder. The studies suggested that atomoxetine did not exacerbate and in fact reduced anxiety symptoms in young patients with comorbid ADHD.

CONCLUSIONS AND IMPLICATIONS

Overall, atomoxetine demonstrates good efficacy in improving anxiety symptoms in children and adolescents with ADHD. Further studies are needed to shed light on atomoxetine's efficacy for anxiety subtypes in ADHD.

Viloxazine, a Non-stimulant Norepinephrine Reuptake Inhibitor, for the Treatment of Attention Deficit Hyperactivity Disorder: A 3 Year Update

Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder in childhood. Current treatment options for ADHD include pharmacological treatment (stimulants, non-stimulants, anti-depressants, anti-psychotics), psychological treatment (behavioral therapy with or without parent training, cognitive training, neurofeedback), and complementary and alternative therapies (vitamin supplementation, exercise). Central nervous system (CNS) stimulants are the primary pharmacological therapy used in treatment; however, these stimulant drugs carry a high potential for abuse and severe psychological/physical dependence. Viloxazine, a non-stimulant medication without evidence of drug dependence, is a selective norepinephrine reuptake inhibitor that has historically been prescribed as an anti-depressant medication. The extended-release (ER) form was approved by the US Food and Drug Administration (FDA) in April 2021 for the treatment of ADHD in pediatric patients aged 6-17 years. Phase 2 and 3 randomized control trials have demonstrated significant efficacy of viloxazine in improving ADHD symptoms versus placebo. Related to its long-standing use as an antidepressant, the safety profile and pharmacokinetics of viloxazine are well understood. Viloxazine appears to be a suitable alternative to current standard-of-care pharmacotherapy for ADHD, but the further investigation remains to be done in comparing its efficacy to that of current treatments.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2021

The second year of the COVID-19 pandemic had no adverse effect on the number of new drug approvals by the US Food and Drug Administration (FDA). Quite the contrary, with a total of 50 new drugs, 2021 belongs to the most successful FDA years. We assign these new drugs to one of three levels of innovation: (1) first drug against a condition ("first-in-indication"), (2) first drug using a novel molecular mechanism ("first-in-class"), and (3) "next-in-class", i.e., a drug using an already exploited molecular mechanism. We identify 21 first-in-class, 28 next-in-class, and only one first-in-indication drugs. By treatment area, the largest group is once again cancer drugs, many of which target specific genetic alterations. Every second drug approved in 2021 targets an orphan disease, half of them being cancers. Small molecules continue to dominate new drug approvals, followed by antibodies and non-antibody biopharmaceuticals. In 2021, the FDA continued to approve drugs without strong evidence of clinical effects, best exemplified by the aducanumab controversy.

Evaluating the pharmacokinetics of extended release viloxazine in the treatment of children with attention-deficit/hyperactivity disorder

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder of childhood and impacts function negatively in multiple settings. Current treatments include stimulants, which inhibit the reuptake of dopamine and norepinephrine, a nonstimulant norepinephrine reuptake inhibitor (NRI) atomoxetine, and alpha-2 agonists clonidine extended release (ER) and guanfacine ER. Despite the effectiveness of these medications some patients do not respond to available drugs or may experience tolerability issues that hinder their use.

AREAS COVERED

Viloxazine, a serotonin norepinephrine modulating agent, was used outside of the United States (U.S.) as an effective antidepressant for several decades, but its use fell out of favor due to the need for multiple daily dosing. An ER viloxazine formulation was recently approved by the U. S. Food and Drug Administration (FDA) for the treatment of ADHD. The efficacy, pharmacokinetics and metabolism of viloxazine and viloxazine ER are reviewed.

EXPERT OPINION

Viloxazine ER is the first nonstimulant approved to treat ADHD in more than a decade. Although they have not been directly compared, the effect size of viloxazine ER is less than has been observed for stimulants. However, its pharmacokinetic properties and tolerability make viloxazine ER a useful addition to the collection of FDA approved ADHD treatments.

Extended-Release Viloxazine for Children and Adolescents With Attention Deficit Hyperactivity Disorder

Non-stimulant medication therapy for children, adolescents, and young adults with attention-deficit/hyperactivity disorder (ADHD) has included alpha 2-agonists (guanfacine and clonidine) as well as a norepinephrine reuptake inhibitor (atomoxetine) for multiple years. Although these may be effective options for some children, they are generally considered to be less effective than stimulant medications. In addition, there has been a suicidal ideation concern in early-late adolescence with atomoxetine, emphasizing the need for continued development of other treatment options. Extended-release viloxazine (SPN-812) has been shown in phase 2 and phase 3 trials to be an effective, well-tolerated alternative for some children with ADHD. The mechanism of action of viloxazine is unique, modulating activity of both serotonin and norepinephrine. Treatment-related adverse events most commonly seen included somnolence, decreased appetite, and headache. Although continued evaluation to confirm the reduced symptoms of ADHD in children along with the safety profile is needed, extended-release viloxazine may offer a once-a-day pharmaceutical treatment option for patients in which stimulant medication is not effective or not a favorable option. It may also be beneficial for those children and adolescents with a comorbidity of depression.

Viloxazine for Attention-Deficit Hyperactivity Disorder: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Background

Recently, the United States Food and Drug Administration (USFDA) approved viloxazine extended-release (ER) to manage attention-deficit hyperactivity disorder (ADHD) in pediatric patients of 6-17 years of age.

Objective

To perform a meta-analysis to determine the safety and efficacy of viloxazine ER in the management of ADHD.

Data Source and Methods

A literature search was performed through the databases Cochrane Library, PubMed, and clinicaltrials.gov, for a period from inception to August 2021, with the keywords: viloxazine, SPN-812, ADHD, and randomized clinical trials. The randomized controlled trials published in English language that analyzed the efficacy and safety were included. The risk of bias (RoB) was assessed by RoB tool. The outcomes included in this study were the proportion of patients with a 50% reduction in ADHD-Rating Scale-5 (ADHD-RS-5 responders) and improvement in CGI-I scale and the proportion of patients with at least one adverse event, the incidence of somnolence and Serious Adverse Events (SAEs).

Results

This meta-analysis includes 1605 patients from five randomized clinical trials; all of the trials were at low risk of bias. Viloxazine group had more ADHD-RS-5 responders as compared to placebo; RR = 1.62; 95% CI = 1.36-1.93; P = <.00001. Significantly higher number of patients showed improved CGI-I score; RR = 1.53; 95% CI = 1.32-1.78; P = <.00001. A higher proportion of patients was observed with at least one adverse event (RR = 1.52; 95% CI = 1.24-1.85; P = <.0001), and somnolence (RR = 3.93; 95% CI = 2.11-7.31; P = <.0001) in viloxazine group. The incidence of SAEs was more in viloxazine group (RR = 2.98; 95% CI = .67-13.3; P = .15).

Conclusions

Viloxazine was found to be significantly superior to placebo in both efficacy outcomes. Adverse events and somnolence were significantly more than the placebo. The incidence was SAEs was more in the viloxazine group but was not statistically significant.

Current and future nonstimulants in the treatment of pediatric ADHD: monoamine reuptake inhibitors, receptor modulators, and multimodal agents

Attention-deficit/hyperactivity disorder (ADHD), the single most common neuropsychiatric disorder with cognitive and behavioral manifestations, often starts in childhood and usually persists into adolescence and adulthood. Rarely seen alone, ADHD is most commonly complicated by other neuropsychiatric disorders that must be factored into any intervention plan to optimally address ADHD symptoms. With more than 30 classical Schedule II (CII) stimulant preparations available for ADHD treatment, only three nonstimulants (atomoxetine and extended-release formulations of clonidine and guanfacine) have been approved by the United States Food and Drug Administration (FDA), all of which focus on modulating the noradrenergic system. Given the heterogeneity and complex nature of ADHD in most patients, research efforts are identifying nonstimulants which modulate pathways beyond the noradrenergic system. New ADHD medications in clinical development include monoamine reuptake inhibitors, monoamine receptor modulators, and multimodal agents that combine receptor agonist/antagonist activity (receptor modulation) and monoamine transporter inhibition. Each of these "pipeline" ADHD medications has a unique chemical structure and differs in its pharmacologic profile in terms of molecular targets and mechanisms. The clinical role for each of these agents will need to be explored with regard to their potential to address the heterogeneity of individuals struggling with ADHD and ADHD-associated comorbidities. This review profiles alternatives to Schedule II (CII) stimulants that are in clinical stages of development (Phase 2 or 3). Particular attention is given to viloxazine extended-release, which has completed Phase 3 studies in children and adolescents with ADHD.

Embryonic Exposure to Tryptophan Yields Bullying Victimization via Reprogramming the Microbiota-Gut-Brain Axis in a Chicken Model

Maternal metabolic disorder during early pregnancy may give rise to emotional and behavioral disorders in the child, vulnerable to bullying. Placental tryptophan fluctuation consequently disrupts offspring gut microbiome and brain neurogenesis with long-lasting physiological and social behavioral impacts. The aim of this study was to examine the hypothesis that the excess gestational tryptophan may affect children’s mental and physical development via modifying the microbiota-gut-brain axis, which lays the foundation of their mental status. Chicken embryo was employed due to its robust microbiota and independence of maternal influences during embryogenesis. The results indicated that embryonic tryptophan exposure reduced body weight and aggressiveness in the male offspring before and during adolescence. Additionally, the relative gut length and crypt depth were increased, while the villus/crypt ratio was decreased in tryptophan treated roosters, which was corresponding to the changes in the cecal microbiota composition. Furthermore, the catecholamine concentrations were increased in tryptophan group, which may be associated with the alterations in the gut microbiome and the gut-brain axis’s function. These changes may underlie the sociometric status of bullying; clarify how gestational tryptophan fluctuation compromises bullying and provide a strategy to prevent bullying by controlling dietary tryptophan and medication therapy during pregnancy.

New Drugs to Treat ADHD: Opportunities and Challenges in Research and Development

Since the landmark MTA (Multimodal Treatment of ADHD) trial unequivocally demonstrated the efficacy of methylphenidate, catecholaminergic drugs, especially stimulants, have been the therapeutic mainstay in treatment of Attention-Deficit Hyperactivity Disorder (ADHD). We review the new drugs which have entered the ADHD formulary. The lessons learned from drug-candidates that have succeeded in clinical trials together with those that have not have also been considered. What emerges confirms and consolidates the hypothesis that clinically effective ADHD drugs indirectly or directly increase catecholaminergic neurotransmission in the prefrontal cortex (PFC). Attempts to enhance catecholaminergic signalling through modulatory neurotransmitter systems or cognitive-enhancing drugs have all failed. New drugs approved for ADHD are catecholaminergic reuptake inhibitors and releasing agents, or selective noradrenaline reuptake inhibitors. Triple reuptake inhibitors with preferential effects on dopamine have not been successful. The substantial number of failures probably accounts for a continued focus on developing novel catecholaminergic and noradrenergic drugs, and a dearth of drug-candidates with novel mechanisms entering clinical development. However, substantial improvements in ADHD pharmacotherapy have been achieved by the almost exclusive use of once-daily medications and prodrugs, e.g. lisdexamfetamine and Azstarys^®, which improve compliance, deliver greater efficacy and reduce risks for diversion and abuse.

A Phase III, Randomized, Double-Blind, Placebo-Controlled Trial Assessing the Efficacy and Safety of Viloxazine Extended-Release Capsules in Adults with Attention-Deficit/Hyperactivity Disorder

BACKGROUND AND OBJECTIVE

Attention-deficit/hyperactivity disorder is a neurodevelopmental disorder that typically begins in childhood and often persists into adulthood. Recent phase III trials have demonstrated the efficacy and safety of viloxazine extended-release capsules (viloxazine ER; Qelbree^®) in pediatrics (6-17 years of age). The aim of this study was to evaluate the efficacy and safety of viloxazine ER in adults with attention-deficit/hyperactivity disorder.

METHODS

This was a phase III, randomized, double-blind, placebo-controlled, two-arm trial in adults (18-65 years of age) with attention-deficit/hyperactivity disorder. Eligible subjects were randomized 1:1 to viloxazine ER (flexible dose of 200-600 mg/day) or matched placebo. The primary efficacy endpoint was the change from baseline at end of study (week 6) in the Adult ADHD Investigator Symptom Rating Scale (AISRS) total score. The key secondary endpoint was the change from baseline at end of study in the Clinical Global Impressions-Severity of Illness (CGI-S) score. Additional secondary outcome measures included the AISRS Inattention and Hyperactivity/Impulsivity subscales, the Behavior Rating Inventory of Executive Function-Adult (BRIEF-A), the Generalized Anxiety Disorder-7 Item (GAD-7), and the Clinical Global Impressions-Improvement (CGI-I); each was analyzed at end of study. Responder rates on CGI scales and the AISRS were also assessed.

RESULTS

A total of 374 subjects were randomized. At end of study, the mean viloxazine ER dose was 504 mg. The reduction in the change from baseline at end of study AISRS total score (least-square means ± standard error) was significantly greater in subjects treated with viloxazine ER (-15.5 ± 0.91) compared with placebo (-11.7 ± 0.90), p = 0.0040. The reduction in the CGI-S score was also significantly greater in subjects treated with viloxazine ER (-1.4 ± 0.10) compared with placebo (-1.0 ± 0.10), p = 0.0023. The viloxazine ER group demonstrated significantly greater improvements in the AISRS Inattention (p = 0.0015) and Hyperactivity/Impulsivity (p = 0.0380) subscales, the CGI-I (p = 0.0076), and the BRIEF-A Global Executive Composite (p = 0.0468) and Metacognition Index (p = 0.0100). Analysis of categorical secondary endpoints revealed that the viloxazine ER group had a significantly higher AISRS 30% response rate compared with placebo (p = 0.0395); all other comparisons were not significant. Many treatment effects (including the primary and key secondary endpoints) were significant by week 2. The most common treatment-related adverse events that occurred in ≥5% of subjects receiving viloxazine ER were insomnia (14.8%), fatigue (11.6%), nausea (10.1%), decreased appetite (10.1%), dry mouth (9.0%), and headache (9.0%). Viloxazine ER was well tolerated, with a 9.0% discontinuation rate due to adverse events compared with 4.9% in the placebo group.

CONCLUSIONS

Treatment with viloxazine ER resulted in a statistically significant improvement in primary and key secondary endpoints, indicating improvements in attention-deficit/hyperactivity disorder symptomology, executive function, and overall clinical illness severity in adults. Viloxazine ER was well tolerated at the tested doses in adults with attention-deficit/hyperactivity disorder.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT04016779.

A Practical, Evidence-informed Approach to Managing Stimulant-Refractory Attention Deficit Hyperactivity Disorder (ADHD)

Stimulants (methylphenidate or amphetamines) are the recommended first-line option for the pharmacological treatment of individuals with attention deficit hyperactivity disorder (ADHD). However, some patients with ADHD will not respond optimally to stimulants. Here, we discuss strategies to manage stimulant-refractory ADHD, based on the recommendations advanced in clinical guidelines, knowledge of expert practice in the field, and our own clinical recommendations, informed by a comprehensive literature search in PubMed, PsycInfo, EMBASE + EMBASE classic, OVID Medline, and Web of Science (up to 30 March 2021). We first highlight the importance of stimulant optimization as an effective strategy to increase response. We then discuss a series of factors that should be considered before using alternative pharmacological strategies for ADHD, including poor adherence, time action properties of stimulants (and wearing-off of effects), poor tolerability (that prevents the use of higher, more effective doses), excessive focus on or confounding from presence of comorbid non-ADHD symptoms, and tolerance. Finally, we consider the role of non-stimulants and combined pharmacological approaches. While the choice of medication for ADHD is still to a large extent based on a trial-and-error process, there are reasonably accepted data and guidelines to aid in clinical decision-making. It is hoped that advances in precision psychiatry in the years ahead will further guide prescribers to tailor medication choice to the specific characteristics of the patient.

Evaluating the likelihood to be helped or harmed after treatment with viloxazine extended-release in children and adolescents with attention-deficit/hyperactivity disorder

AIMS

When clinicians evaluate potential medications for their patients, they must weigh the probability of a treatment's benefits against the possible risks. To this end, the present analyses evaluate the novel nonstimulant viloxazine extended-release (viloxazine ER) using measures of effect size to describe the potential benefits of its treatment in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) as well as the risk of discontinuation because of intolerable adverse events.

METHODS

These post hoc analyses use pooled data from four pivotal Phase 3 trials in paediatric patients treated with viloxazine ER. The Likelihood to be Helped or Harmed (LHH) effect size measure was calculated to describe the probability of patients benefiting from treatment vs discontinuing. The Number Needed to Treat (NNT) was calculated from frequently used thresholds of response. The Number Needed to Harm (NNH) was calculated using discontinuations because of adverse events.

RESULTS

LHH values for viloxazine ER ranged from 5 to 13, suggesting that subjects were 5-13 times more likely to benefit from, rather than discontinue, viloxazine ER treatment. Specifically, NNT values for viloxazine ER treatment ranged from 6 to 7. NNH values for viloxazine ER treatment ranged from 31 to 74. By convention, single-digit NNTs (<10) suggest the intervention is potentially useful, while NNH values ≥10 for adverse events suggest it is potentially safe or tolerable.

CONCLUSIONS

These results indicate that patients with ADHD are likely to benefit from treatment with viloxazine ER, and are unlikely to discontinue, as viloxazine ER treatment was associated with favourable LHH, NNT, and NNH values. Clinicaltrials.gov: NCT03247530, NCT03247543, NCT03247517, NCT03247556.

Population Pharmacokinetics of Viloxazine Extended-Release Capsules in Pediatric Subjects With Attention Deficit/Hyperactivity Disorder

Viloxazine extended-release capsules (viloxazine ER; Qelbree) is a novel nonstimulant, recently approved by the US Food and Drug Administration for the treatment of ADHD in pediatrics. Here, we characterize the pharmacokinetics (PK) of viloxazine and its major metabolite, 5-HVLX-gluc, using a population PK model and evaluate the impact of 1-4 days of missed viloxazine ER doses on viloxazine PK. Data from 4 phase 3 trials in pediatric subjects treated with viloxazine ER were used to establish the PK model. Covariate analysis was conducted on the final base model. The impact of 1-4 days of missed doses on steady-state viloxazine PK was evaluated using Monte Carlo simulations. A 1-compartmental linear model with first-order absorption and elimination of the parent drug and first-order metabolite formation and elimination properly described the population PK of viloxazine and 5-HVLX-gluc. Body weight impacted the systemic exposure of viloxazine and 5-HVLX-gluc. Predicted PK parameters at steady state (mean ± standard deviation) in children receiving viloxazine ER were determined. C_max was 1.60 ± 0.70 μg/mL at 100 mg, 2.83 ± 1.31 μg/mL at 200 mg, and 5.61 ± 2.48 μg/mL at 400 mg. AUC_0-t was 19.29 ± 8.88 μg·h/mL at 100 mg, 34.72 ± 16.53 μg·h/mL at 200 mg, and 68.00 ± 28.51 μg·h/mL at 400 mg. PK parameters for adolescents receiving viloxazine ER were also determined. C_max was 2.06 ± 0.90 μg/mL at 200 mg, 4.08 ± 1.67 μg/mL at 400 mg, and 6.49 ± 2.87 μg/mL at 600 mg. AUC_0-t was 25.78 ± 11.55 μg·h/mL at 200 mg, 50.80 ± 19.76 μg·h/mL at 400 mg, and 79.97 ± 36.91 μg·h/mL at 600 mg. Simulations revealed that, regardless of the duration of the dosing interruption, viloxazine concentration returned to steady-state levels after approximately 2 days of once-daily dosing of viloxazine ER.

Viloxazine: Pediatric First Approval

Viloxazine (QELBREE™), a selective norepinephrine reuptake inhibitor, is being developed by Supernus Pharmaceuticals as a non-stimulant for the treatment of attention-deficit/hyperactivity disorder (ADHD) in pediatric and adult patients. This is a novel formulation of a pharmacological agent formerly marketed in Europe for the treatment of depression in adults. Viloxazine received its first pediatric approval in April 2021 in the USA for the treatment of ADHD in pediatric patients aged 6-17 years. Approval was based on positive results from a series of short-term phase III clinical trials in which viloxazine improved the severity of ADHD symptoms in children and adolescents with diagnosed ADHD. Viloxazine is available as extended-release capsules for once-daily oral administration. This article summarizes the milestones in the development of viloxazine leading to this first pediatric approval for ADHD.

A Phase 3, Placebo-Controlled Trial of Once-Daily Viloxazine Extended-Release Capsules in Adolescents With Attention-Deficit/Hyperactivity Disorder

PURPOSE

This phase 3 clinical trial evaluated the efficacy and safety of viloxazine extended-release capsules (VLX-ER) as a monotherapy for attention-deficit/hyperactivity disorder (ADHD) in adolescents (12-17 years).

METHODS

Eligible subjects (n = 310) were randomized to receive once-daily 200 and 400 mg VLX-ER, or placebo for 6 weeks. The primary efficacy end point was change from baseline (CFB) at the end of study (EOS) in ADHD Rating Scale-5 Total score. Key secondary end points were Clinical Global Impression-Improvement score at EOS, CFB at EOS in Conners 3-Parent Short Form Composite T-score, and CFB at EOS in Weiss Functional Impairment Rating Scale-Parent Total average score.

RESULTS

In the 200-mg/d and 400-mg/d VLX-ER treatment groups, a significant improvement was found in the CFB at EOS in ADHD Rating Scale-5 Total (P = 0.0232, P = 0.0091) and Inattention (P = 0.0424, P = 0.0390) and Hyperactivity/Impulsivity (P = 0.0069, P = 0.0005) subscale scores versus placebo. The Clinical Global Impression-Improvement score was significantly improved at EOS in the 200-mg/d and 400-mg/d VLX-ER groups versus placebo (P = 0.0042, P = 0.0003). The Conners 3-Parent Short Form composite T-score and Weiss Functional Impairment Rating Scale-Parent Total average score exhibited improvement in both VLX-ER groups; however, the difference versus placebo was not statistically significant. The most common treatment-related adverse events were somnolence, headache, decreased appetite, nausea, and fatigue. The adverse event-related discontinuation rates were <5% in all groups.

CONCLUSIONS

Viloxazine extended-release demonstrated statistically significant and clinically meaningful improvement in ADHD symptoms in adolescents and was generally well tolerated.

Evidence-based pharmacological treatment options for ADHD in children and adolescents

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity, causing functional impairment. Its prevalence lies at approximately 5% in children and adolescents and at approximately 2.5% in adults. The disorder follows a multifactorial etiology and shows a high heritability. Patients show a high interindividual and intraindividual variability of symptoms, with executive deficits in several cognitive domains. Overall, ADHD is associated with high rates of psychiatric comorbidities, and insufficient treatment is linked to adverse long-term outcomes. Current clinical guidelines recommend an individualized multimodal treatment approach including psychoeducation, pharmacological interventions, and non-pharmacological interventions. Available medications include stimulants (methylphenidate, amphetamines) and non-stimulants (atomoxetine, guanfacine, clonidine). While available pharmacological treatment options for ADHD show relatively large effect sizes (in short-term trials) and overall good tolerability, there is still a need for improvement of current pharmacotherapeutic strategies and for the development of novel medications. This review summarizes available pharmacological treatment options for ADHD in children and adolescents, identifies current issues in research and evidence gaps, and provides an overview of ongoing efforts to develop new medications for the treatment of ADHD in children and adolescents by means of a systematic cross-sectional analysis of the clinical trials registry www.clinicaltrials.gov.

Viloxazine in the Management of CNS Disorders: A Historical Overview and Current Status

Viloxazine has a long history of clinical use in Europe as an antidepressant, and has recently been repurposed into an extended-release form for the treatment of attention-deficit/hyperactivity disorder in the USA. An immediate-release formulation was approved for the treatment of depression in the UK in 1974, and was subsequently marketed there and in several European countries for 30 years with no major safety concerns. In contrast to first-generation antidepressants (e.g., tricyclic antidepressants, monoamine oxidase inhibitors), viloxazine was associated with a relatively low risk for cardiotoxicity. Gastrointestinal symptoms were the most commonly reported side effects. The therapeutic effects of viloxazine are thought to be primarily the result of its action as a norepinephrine reuptake inhibitor, although in vitro and preclinical in vivo animal data suggest that viloxazine may also impact the serotoninergic system. This review summarizes the evolving knowledge of viloxazine based on information from previously published preclinical and clinical investigations, and acquired unpublished historical study reports from both open-label and blinded controlled clinical trials. We review the chemical properties, mechanism of action, safety, and tolerability across these studies, and discuss the contemporary rationale for the development of this agent as an extended-release oral formulation for the treatment of attention-deficit/hyperactivity disorder.

Impact of Paroxetine, a Strong CYP2D6 Inhibitor, on SPN-812 (Viloxazine Extended-Release) Pharmacokinetics in Healthy Adults

SPN‐812 (viloxazine extended‐release) is a novel nonstimulant recently approved as a treatment for attention‐deficit/hyperactivity disorder in children and adolescents. Given that SPN‐812 is metabolized by CYP2D6 and may be coadministered with CYP2D6 inhibitors, this trial investigated the pharmacokinetics and safety of SPN‐812 coadministered with the potent CYP2D6 inhibitor paroxetine. In this single‐sequence, 3‐treatment period study in healthy volunteers, subjects received a single oral dose of 700 mg SPN‐812 alone (period 1), 20 mg daily paroxetine (10 days, period 2), followed by concurrent administration of SPN‐812 and paroxetine (period 3). Blood samples were collected for 72 hours post‐SPN‐812 dosing and analyzed for viloxazine and its primary metabolite, 5‐HVLX‐gluc. Twenty‐two healthy adults were enrolled; all completed the trial. The potential for drug interaction between SPN‐812 and paroxetine was assessed using analysis of variance on the log‐transformed pharmacokinetic parameters C_max, AUC_0‐t, and AUC_inf. The least‐squares geometric mean ratios for viloxazine were (reported as the ratio of combination/SPN‐812 alone) C_max, 116.04%; 90%CI, 109.49%‐122.99%; AUC_0‐t, 134.65%; 90%CI, 127.65‐142.03; and AUC_inf, 134.80%; 90%CI, 127.94%‐142.03%. CYP2D6 inhibition resulted in a modest change (<35%) on viloxazine AUCs with no change in C_max. All adverse events were mild in severity.

Translating Attention-Deficit/Hyperactivity Disorder Rating Scale-5 and Weiss Functional Impairment Rating Scale-Parent Effectiveness Scores into Clinical Global Impressions Clinical Significance Levels in Four Randomized Clinical Trials of SPN-812 (Viloxazine Extended-Release) in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

Objectives: Clinical trials in psychiatry frequently report results from lengthy, comprehensive assessments to characterize a subject emotionally, cognitively, and behaviorally before and after treatment. However, the potential treatment implications of these results and how they translate into clinical practice remain unclear. Conversely, the Clinical Global Impressions (CGI) scales are quick, intuitive assessments used to assess the functional impact of a treatment in clinically relevant terms. The objectives of the present analyses are to translate scores from comprehensive assessments of symptom severity and functional impairment into clinically meaningful CGI levels. Methods: These post-hoc analyses use data integrated from four pivotal Phase 3 trials in attention-deficit/hyperactivity disorder (ADHD) in children and adolescents treated with the novel nonstimulant SPN-812 (Viloxazine Extended-Release). In this study, we evaluated the ADHD Rating Scale-5 (ADHD-RS-5) and Weiss Functional Impairment Rating Scale-Parent (WFIRS-P), assessments of symptom severity and functional impairment, respectively, by linking these scales with the CGI scales at baseline and end of study. Results: For participants that improved, a one-level change on the CGI-Improvement (CGI-I) was associated with a 10-15-point change on the ADHD-RS-5, and a 0.2-0.5-point change on the WFIRS-P. On the CGI-I, ratings of much improved and very much improved were associated with a percent score decrease (i.e., improvement) of ∼55% and 80% on the ADHD-RS-5 and ∼40% and 70% on the WFIRS-P, respectively. Differences between children and adolescents were minor and are unlikely to be clinically meaningful. Conclusion: These post-hoc analyses provide clinically meaningful benchmarks for the interpretation of scores on the ADHD-RS-5 and WFIRS-P in terms of CGI evaluations in subjects with ADHD. These results may be useful for physicians seeking to understand a treatment's potential impact on their ADHD patients or for researchers looking to define their study results within a clinically relevant context. Data are from clinical trials NCT03247530, NCT03247543, NCT03247517, and NCT03247556.