A systematic review of combination therapy with stimulants and atomoxetine for attention-deficit/hyperactivity disorder, including patient characteristics, treatment strategies, effectiveness, and tolerability

Treating Executive Function in Youth With Attention Deficit Hyperactivity Disorder: A Review of Pharmacological and Non-Pharmacological Interventions

INTRODUCTION

Executive function (EF) deficits are common in youth with ADHD and pose significant functional impairments. The extent and effect of interventions addressing EF in youth with ADHD remain unclear.

METHODS

We conducted a systematic literature review using PRISMA guidelines. Included studies were randomized controlled trials of interventions to treat EF in youth with ADHD.

RESULTS

Our search returned 136 studies representing 11,443 study participants. We identified six intervention categories: nonstimulant pharmacological (N = 3,576 participants), neurological (N = 1,935), psychological (N = 2,387), digital (N = 2,416), physiological (N = 680), and combination (N = 366). The bulk of the evidence supported pharmacological interventions as most effective in mitigating EF, followed by psychological and digital interventions.

CONCLUSION

A breadth of treatments exists for EF in youth with ADHD. Pharmacological, psychotherapeutic, and digital interventions had the most favorable, replicable outcomes. A lack of outcome standardization across studies limited treatment comparison. More data on the persistence of intervention effects are necessary.

Effectiveness and Tolerability of Combination Pharmacotherapy With Stimulant and Non-Stimulant in Children With Attention Deficit Hyperactivity Disorder

Objectives

This study aimed to investigate the effectiveness and safety of combining psychostimulants and nonstimulants for patients under treatment for attention deficit hyperactivity disorder (ADHD).

Methods

The study included 96 patients aged 6-12 years who were diagnosed with ADHD, among whom 34 received combination pharmacotherapy, 32 received methylphenidate monotherapy, and 30 received atomoxetine monotherapy. Statistical analysis was conducted to compare treatment and adverse effects among groups and to analyze changes before and after combination pharmacotherapy. The difference between combination pharmacotherapy and monotherapy was investigated. Logistic regression analysis was used to identify the predictors of combination pharmacotherapy.

Results

No significant differences were observed between the groups in terms of age or pretreatment scores. The most common adverse effect experienced by 32% of patients in the combination pharmacotherapy group was decreased appetite. Clinical global impression- severity score decreased significantly after combination pharmacotherapy. All three groups showed significant clinical global impression- severity score improvements over time, with no significant differences among them. The predictive factors for combination pharmacotherapy included the Child Behavior Checklist total score internalizing subscale.

Conclusion

Combination pharmacotherapy with methylphenidate and atomoxetine is a relatively effective and safe option for patients with ADHD who do not respond to monotherapy.

Pediatric attention deficit hyperactivity disorder (ADHD): 2022 updates on pharmacological management

INTRODUCTION

Pediatric attention-deficit disorder (ADHD) impacts a significant percentage of the population world-wide. Pharmacologic treatments have been shown to be safe and effective for managing symptoms. Various medication formulations exist, and new medication agents are continually approved each year.

AREAS COVERED

This article offers an overview of ADHD, an overview of both stimulant and non-stimulant medication options as well as an overview of stimulant misuse. It explores the medication mechanisms of action and side effect profiles, as well as offering an in-depth summary of the novel agents recently approved and soon-to-be approved for use in youth. PubMed and Medline were utilized. Search terms included children, adolescents, ADHD, and medication. FDA package inserts were reviewed for all medications.

EXPERT OPINION

New formulations of medications include an evening administered, extended, and delayed-release form of methylphenidate (DR/ER MPH), a methylphenidate pro-drug (serdexmethylphenidate) and an amphetamine patch. The availability of a new SNRI (selective norepinephrine reuptake inhibitor), viloxazine extended-release (VER), and the pending approval of a triple reuptake inhibitor (centanafadine) provides welcome additions to the prescriber's toolbox.

Pharmacotherapy in autism spectrum disorders, including promising older drugs warranting trials

Available pharmacotherapies for autism spectrum disorders (ASD) are reviewed based on clinical and research experience, highlighting some older drugs with emerging evidence. Several medications show efficacy in ASD, though controlled studies in ASD are largely lacking. Only risperidone and aripiprazole have Federal Drug Administration approval in the United States. Methylphenidate (MPH) studies showed lower efficacy and tolerability for attention deficit hyperactivity disorder (ADHD) than in the typically developing (TD) population; atomoxetine demonstrated lower efficacy but comparable tolerability to TD outcomes. Guanfacine improved hyperactivity in ASD comparably to TD. Dex-troamphetamine promises greater efficacy than MPH in ASD. ADHD medications reduce impulsive aggression in youth, and may also be key for this in adults. Controlled trials of the selective serotonin reuptake inhibitors citalopram and fluoxetine demonstrated poor tolerability and lack of efficacy for repetitive behaviors. Trials of antiseizure medications in ASD remain inconclusive, however clinical trials may be warranted in severely disabled individuals showing bizarre behaviors. No identified drugs treat ASD core symptoms; oxytocin lacked efficacy. Amitriptyline and loxapine however, show promise. Loxapine at 5-10 mg daily resembled an atypical antipsychotic in positron emission tomography studies, but may be weight-sparing. Amitriptyline at approximately 1 mg/ kg/day used cautiously, shows efficacy for sleep, anxiety, impulsivity and ADHD, repetitive behaviors, and enuresis. Both drugs have promising neurotrophic properties.

Pharmacotherapy May Attenuate the Risk of Child Abuse in Attention-Deficit/Hyperactivity Disorder from the Real-World Evidence

Objective: Psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD), may serve as a risk factor for child abuse. Methods: This study aimed to evaluate the association between children and adolescents with ADHD diagnosis and the risk of child abuse. The effectiveness of a pharmacological intervention on reducing the risk of child abuse was also assessed. A nationwide, population-based, retrospective with a matched-cohort study design was used. Data were from the National Health Insurance Research Database of Taiwan over a 15-year period (2000-2015). Results: Increased risk of child abuse in the ADHD group was noticed and the adjusted hazard ratio (HR) was 1.797 (95% confidence interval [CI] = 1.245-2.388, p < 0.001). The Kaplan-Meier analysis showed a significantly higher cumulative incidence in the ADHD group over the 15-year period (Log-rank test p < 0.001). ADHD patients with other psychiatric comorbidities had a higher risk of child abuse. Pharmacological treatment of either methylphenidate or atomoxetine was associated with a reduced risk of child abuse. The total adjusted HR was 1.466 (95% CI = 1.077-1.883, p < 0.001) in medicine group compared with the controls. Conclusions: ADHD was associated with a subsequent risk of child abuse in Taiwan. Pharmacological treatment could reduce the risk of child abuse in ADHD patients.

Examining the biological mechanisms of human mental disorders resulting from gene-environment interdependence using novel functional genomic approaches

We explore how functional genomics approaches that integrate datasets from human and non-human model systems can improve our understanding of the effect of gene-environment interplay on the risk for mental disorders. We start by briefly defining the G-E paradigm and its challenges and then discuss the different levels of regulation of gene expression and the corresponding data existing in humans (genome wide genotyping, transcriptomics, DNA methylation, chromatin modifications, chromosome conformational changes, non-coding RNAs, proteomics and metabolomics), discussing novel approaches to the application of these data in the study of the origins of mental health. Finally, we discuss the multilevel integration of diverse types of data. Advance in the use of functional genomics in the context of a G-E perspective improves the detection of vulnerabilities, informing the development of preventive and therapeutic interventions.

Dose titration of osmotic release oral system methylphenidate in children and adolescents with attention-deficit hyperactivity disorder: a retrospective cohort study

BACKGROUND

Osmotic release oral system methylphenidate (OROS-MPH) is one of the most commonly used medication for attention-deficit hyperactivity disorder (ADHD), however, real-world knowledge on OROS-MPH dose titration has been limited. This study aims to summarize and visualise the OROS-MPH titration patterns in children and adolescents with ADHD in the United States (US) and Japan.

METHODS

This retrospective cohort study used the US IBM® MarketScan® Commercial Claims and Encounters database from 2000 to 2019 and the Japan Medical Data Centre database from 2008 to 2019. New OROS-MPH users with ADHD were identified and split into child (6 to < 13 years) and adolescent (13 to < 18 years) groups according to age at OROS-MPH initiation/reinitiation. Patient characteristics and OROS-MPH treatment patterns were described. OROS-MPH dose titration pathways were visualised by Sankey diagrams.

RESULTS

We included 98,973 children and 62,002 adolescents in the US cohort, and 4595 children and 1508 adolescents in the Japanese cohort. In Japanese cohort, 91.9% of children and 77.9% of adolescents initiated OROS-MPH at the lowest dose (18 mg/day), whereas US patients had a broader distribution of initial doses (e.g., 18-54 mg/day). The US patients had higher daily dose of OROS-MPH than Japanese patients. Overall, a minority (< 40%) of the OROS-MPH users underwent dose titration, and different titration patterns were observed between the US and Japanese patients.

CONCLUSIONS

Different treatment and titration patterns of OROS-MPH were observed in the two countries. Additional real-world studies about clinical reasoning underlying dose selection are needed to support clinical decision-making.

Combined Medication with Stimulants and Non-stimulants for Attention-deficit/hyperactivity Disorder

Objective

To study the efficiency and indication of combined medication with a stimulant and non-stimulant for attention-deficiency/hyperactivity disorder (ADHD), herein, the authors examined children and adult patients with ADHD.

Methods

Subjects included patients diagnosed with ADHD who paid two or more visits to the outpatient clinic of the Kyung Hee University hospital from January 2009 to December 2019. The authors examined the age, sex, drugs, treatment adherence, and reason for combined medication. The subjects were classified into four groups treatment with a non-stimulant (atomoxetine) only (Group ATX), treatment with a stimulant (methylphenidate immediate-release, extended-release, or osmotic-release oral system) only (Group MPH), exposed to both but separately used (Group SEP), and exposed to both with combined use (Group COM). The patient was considered adherent to treatment (1) on visiting the hospital ten or more times or consecutively for six months, and (2) medication possession ratio ≥ 0.8.

Results

Of 929 patients, 229 (24.7%) were female. Group ATX comprised 146 (15.7%) patients, Group MPH comprised 627 (67.5%) patients, Group SEP comprised 106 (11.4%) patients, and Group COM comprised 50 (5.4%) patients. Longer-term adherence was seen with combined medication and in females than with monopharmacy and in males. The main indication for combination was dose-limiting untoward effects.

Conclusion

These results suggest that combined medication would facilitate treatment adherence for ADHD. Further research is essential for the replication of these results in a large sample and the investigation of the indications for administering combined medication in children and adults with ADHD.

Trends in Antipsychotic Medication Use in Young Privately Insured Children

OBJECTIVE

To estimate trends of annual antipsychotic medication use by privately insured young children (aged 2-7 years) in the United States, and to describe the clinical and treatment characteristics of these children.

METHOD

The study population included young children from a nationwide commercial claims database (2007-2017). We estimated annual antipsychotic use by age and sex, defined as the number of children dispensed an antipsychotic per year divided by the number enrolled. We described clinical diagnoses and mental health service use in those with prescription antipsychotic use in 2009 and 2017.

RESULTS

Annual antipsychotic use in young children was 0.27% in 2007, peaked at 0.29% in 2009, and statistically significantly declined to 0.17% by 2017 (linear trend: -0.017% per year, 95% CI: -0.018 to -0.016). Antipsychotic use was higher in boys than in girls. A greater proportion of antipsychotic users received a mental disorder diagnosis in 2017 (89%) than in 2009 (86%, p < .01). The most common clinical diagnoses in antipsychotic users, under a hierarchical classification, were pervasive developmental disorder (2009 = 27%, 2017 = 38%, p < .01), conduct or disruptive behavior disorder (2009 = 15%, 2017 = 21%, p < .01), and attention-deficit/hyperactivity disorder (2009 = 24%, 2017 = 18%, p < .01). Among 2017 antipsychotic users, 32% had 4+ psychotherapy claims, 43% had a psychiatrist visit, and the majority used another psychotropic medication, most commonly a stimulant (boys = 57%, girls = 50%).

CONCLUSION

In privately insured young children, antipsychotic use declined from 2009 to 2017, with shifts toward indications with some supporting evidence. Nevertheless, a majority of use remains off label and for conditions lacking effectiveness and safety data. Improving antipsychotic prescribing in young children remains a challenge.

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.

Synergistic efficacy and diminished adverse effect profile of composite treatment of several ADHD medications

Although attention-deficit/hyperactivity disorder (ADHD) is widely studied, problems regarding the adverse effect risks and non-responder problems still need to be addressed. Combination pharmacotherapy using standard dose regimens of existing medication is currently being practiced mainly to augment the therapeutic efficacy of each drug. The idea of combining different pharmacotherapies with different molecular targets to alleviate the symptoms of ADHD and its comorbidities requires scientific evidence, necessitating the investigation of their therapeutic efficacy and the mechanisms underlying the professed synergistic effects. Here, we injected male ICR mice with MK-801 to induce ADHD behavioral condition. We then modeled a "combined drug" using sub-optimal doses of methylphenidate, atomoxetine, and fluoxetine and investigated the combined treatment effects in MK-801-treated mice. No sub-optimal dose monotherapy alleviated ADHD behavioral condition in MK-801-treated mice. However, treatment with the combined drug attenuated the impaired behavior of MK-801-treated animals. Growth impediment, sleep disturbances, or risk of substance abuse were not observed in mice treated subchronically with the combined drugs. Finally, we observed that the combined ADHD drug rescued alterations in p-AKT and p-ERK1/2 levels in the prefrontal cortex and hippocampus, respectively, of MK-801-treated mice. Our results provide experimental evidence of a possible new pharmacotherapy option in ameliorating the ADHD behavioral condition without the expected adverse effects. The detailed mechanism of action underlying the synergistic therapeutic efficacy and reduced adverse reaction by combinatorial drug treatment should be investigated further in future studies.

Risk factors for low adherence to methylphenidate treatment in pediatric patients with attention-deficit/hyperactivity disorder

Poor adherence is a major concern in the treatment of attention-deficit/hyperactivity disorder (ADHD). The objective of this study was to evaluate factors linked to early interruption of and low adherence to treatment with osmotic-release oral system methylphenidate hydrochloride (OROS-MPH) in pediatric patients with ADHD. A total of 1353 young people (age 6–17 years) with a diagnosis of ADHD who newly started OROS-MPH were extracted from the pharmacoepidemiological data of 3 million people in Japan. The cohort was retrospectively surveyed every month for 12 months. Ten possible risk factors were extracted from the data and analyzed by multivariable logistic regression. Sensitivity analysis was conducted to ensure the robustness of the analysis. The results revealed that treatment adherence was generally poor, with a tendency for discontinuation in the early stage. Multivariable logistic regression results showed that adherence is reduced by female sex, lower starting dose, and concomitant atomoxetine or hypnotics. These findings may help clinicians to predict the risk of poor adherence in the early stage of treatment and improve not only patients’ symptoms, but also their quality of life.

Prefrontal Cortex Dopamine Transporter Gene Network Moderates the Effect of Perinatal Hypoxic-Ischemic Conditions on Cognitive Flexibility and Brain Gray Matter Density in Children

BACKGROUND

Genetic polymorphisms of the dopamine transporter gene (DAT1) and perinatal complications associated with poor oxygenation are risk factors for attentional problems in childhood and may show interactive effects.

METHODS

We created a novel expression-based polygenic risk score (ePRS) reflecting variations in the function of the DAT1 gene network (ePRS-DAT1) in the prefrontal cortex and explored the effects of its interaction with perinatal hypoxic-ischemic-associated conditions on cognitive flexibility and brain gray matter density in healthy children from two birth cohorts-MAVAN from Canada (n = 139 boys and girls) and GUSTO from Singapore (n = 312 boys and girls).

RESULTS

A history of exposure to several perinatal hypoxic-ischemic-associated conditions was associated with impaired cognitive flexibility only in the high-ePRS group, suggesting that variation in the prefrontal cortex expression of genes involved in dopamine reuptake is associated with differences in this behavior. Interestingly, this result was observed in both ethnically distinct birth cohorts. Additionally, parallel independent component analysis (MAVAN cohort, n = 40 children) demonstrated relationships between single nucleotide polymorphism-based ePRS and gray matter density in areas involved in executive (cortical regions) and integrative (bilateral thalamus and putamen) functions, and these relationships differ in children from high and low exposure to hypoxic-ischemic-associated conditions.

CONCLUSIONS

These findings reveal that the impact of conditions associated with hypoxia-ischemia on brain development and executive functions is moderated by genotypes associated with dopamine signaling in the prefrontal cortex. We discuss the potential impact of innovative genomic and environmental measures for the identification of children at high risk for impaired executive functions.

Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents

Attention-deficit/hyperactivity disorder (ADHD) is 1 of the most common neurobehavioral disorders of childhood and can profoundly affect children's academic achievement, well-being, and social interactions. The American Academy of Pediatrics first published clinical recommendations for evaluation and diagnosis of pediatric ADHD in 2000; recommendations for treatment followed in 2001. The guidelines were revised in 2011 and published with an accompanying process of care algorithm (PoCA) providing discrete and manageable steps by which clinicians could fulfill the clinical guideline's recommendations. Since the release of the 2011 guideline, the Diagnostic and Statistical Manual of Mental Disorders has been revised to the fifth edition, and new ADHD-related research has been published. These publications do not support dramatic changes to the previous recommendations. Therefore, only incremental updates have been made in this guideline revision, including the addition of a key action statement related to diagnosis and treatment of comorbid conditions in children and adolescents with ADHD. The accompanying process of care algorithm has also been updated to assist in implementing the guideline recommendations. Throughout the process of revising the guideline and algorithm, numerous systemic barriers were identified that restrict and/or hamper pediatric clinicians' ability to adopt their recommendations. Therefore, the subcommittee created a companion article (available in the Supplemental Information) on systemic barriers to the care of children and adolescents with ADHD, which identifies the major systemic-level barriers and presents recommendations to address those barriers; in this article, we support the recommendations of the clinical practice guideline and accompanying process of care algorithm.

Le TDAH chez les enfants et les adolescents, partie 2 : le traitement

Le trouble de déficit de l’attention/hyperactivité (TDAH) est un trouble neurodéveloppemental chronique. La Société canadienne de pédiatrie a préparé trois documents de principes après avoir effectué des analyses bibliographiques systématiques. Leurs objectifs s’établissent comme suit : 1) Résumer les données probantes cliniques à jour sur le TDAH. 2) Établir une norme pour les soins du TDAH. 3) Aider les cliniciens canadiens à prendre des décisions éclairées et fondées sur des données probantes pour rehausser la qualité des soins aux enfants et aux adolescents qui présentent cette affection.

La partie 2, axée sur le traitement, porte sur les données probantes et le contexte entourant diverses approches cliniques, la combinaison des interventions comportementales et pharmacologiques pour assurer un traitement plus efficace, le rôle de la formation des parents et des enseignants (ou des autres personnes qui s’occupent de l’enfant), le recours aux stimulants et aux non-stimulants, leurs effets et leurs risques, leur posologie et les protocoles de surveillance. Les recommandations thérapeutiques reposent sur les lignes directrices à jour, les données probantes tirées de publications scientifiques et le consensus d’experts.

ADHD in children and youth: Part 2-Treatment

Attention-deficit hyperactivity disorder (ADHD) is a chronic neurodevelopmental disorder. Three position statements have been developed by the Canadian Paediatric Society, following systematic literature reviews. Statement objectives are to: 1) Summarize the current clinical evidence regarding ADHD,2) Establish a standard for ADHD care, and3) Assist Canadian clinicians in making well-informed, evidence-based decisions to enhance care of children and youth with this condition. Specific topics reviewed in Part 2, which focuses on treatment, include: evidence and context for a range of clinical approaches, combining behavioural and pharmacological interventions to address impairment more effectively, the role of parent and teacher (or other caregiver) training, the use of stimulant and nonstimulant medications, with effects and risks, and dosing and monitoring protocols. Treatment recommendations are based on current guidelines, evidence from the literature, and expert consensus.

Psychiatric Treatment and Management of Psychiatric Comorbidities of Movement Disorders

Pediatric movement disorders may present with psychiatric symptoms at many points during the course of the disease. For the relatively common pediatric movement disorder, Tourette syndrome, psychiatric comorbidities are well-described and treatment is well-studied. Managing these comorbidities may be more effective than improving the movements themselves. For more uncommon movement disorders, such as juvenile-onset Huntington disease, treatment of psychiatric comorbidities is not well-characterized, and best-practice recommendations are not available. For the least common movement disorders, such as childhood neurodegeneration with brain iron accumulation, psychiatric features may be nonspecific so that underlying diagnosis may be apparent only after recognition of other symptoms. However, psychiatric medication, psychotherapy, and psychosocial support for these disorders may prove helpful to many children and adolescents.

Longitudinal Impact of a Randomized Clinical Trial to Improve Family Function, Reduce Maternal Stress and Improve Child Outcomes in Families of Children with ADHD

Objective Evaluate the efficacy of a 12 month nursing case-management intervention over a period of 18 months, 6 months after the end of intervention, for families of children attention deficit hyperactivity disorder (ADHD). Methods Mother and child dyads were enrolled to participate in a randomized controlled clinical trial. Children were 4-18 years old. Data were collected at baseline, 6, 12, and 18 months or 6 months after the termination of direct intervention. Longitudinal analyses, using generalized estimating equations, were conducted to assess change in study outcomes relating to family function, maternal stress, and child behavior over the 18 month period. Results Compared to control families, some family function outcomes were moderately improved in the intervention group. In particular, intervention families demonstrated substantial improvement in implementing family behavior controls (p value = 0.038) and improvement in family satisfaction (not statistically significant p = 0.062). Although there was improvement in the overall family function measure there was not a statistically significant difference between groups. Maternal stress and child behavior outcomes were not significantly different between control and intervention groups by the end of the intervention. Conclusions for Practice Addressing ADHD is complex and requires the assessment of comorbidities that might exacerbate negative behavior. Our findings support the latest American Academy of Pediatrics guidelines to use behavioral therapy as the first line of treatment in young children. Nursing case-management interventions that provide direct family education and improve family function, especially with respect to providing structure and behavior control, may complement and facilitate behavioral therapy for treatment of ADHD and improving child behavior.

The Clinical Pharmacokinetics of Amphetamines Utilized in the Treatment of Attention-Deficit/Hyperactivity Disorder

Amphetamine (AMP), an indirectly acting psychostimulant approved for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children, adolescents, and adults, is among the most long-standing therapeutic agents in all of clinical psychopharmacology. This review focuses on AMP absorption, metabolism, and elimination brought to bear on comparative pharmacokinetics in its various formulations. A comprehensive search of the published literature was conducted using MEDLINE (PubMed) and Google Scholar databases through April 2017 to retrieve all pertinent in vitro and human studies for review and synthesis. Additionally, Food and Drug Administration (FDA) databases were accessed for otherwise unavailable data when possible. Initially available as racemic (dl)-AMP, this drug was later supplanted by enantiopure (d)-AMPH or enantioenriched (75:25 dl)-AMP formulations; although racemic AMP returned as an approved drug to treat ADHD in 2014. Presently, there are several immediate-release (IR) formulations available, including d-AMP, dl-AMP, and mixed amphetamine salts, which are neither racemic nor the pure d-enantiomer (i.e., a 3:1 mixture of d-AMP and l-AMP). Furthermore, new modified-release AMP formulations, including an oral suspension and an orally disintegrating tablet, are now available. A lysine-bonded prodrug form of d-AMP also serves as a treatment option. Oral AMP is rapidly absorbed, with high absolute bioavailability, followed by extensive metabolism involving multiple enzymes. Some metabolic pathways exhibit stereoselective biotransformations favoring the l-isomer substrate. Drug exposure exhibits dose-proportional pharmacokinetics. Body weight is a fundamental determinant of differences in observed AMP plasma concentrations. IR formulations typically provide a T_max from 2 to 3 hours. In replicated studies, children exhibit a shorter plasma T_1/2 (∼7 hours) relative to adults (∼10 to 12 hours). There are few documented pharmacokinetic drug interactions of clinical significance beyond influences of drug-induced alteration of urinary pH. The array of AMP formulations addressed in this review offer flexibility in dosing, drug onset, and offset to assist in individualized pharmacotherapy of ADHD.

Neural correlates of atomoxetine improving inhibitory control and visual processing in Drug-naïve adults with attention-deficit/hyperactivity disorder

Atomoxetine improves inhibitory control and visual processing in healthy volunteers and adults with attention-deficit/hyperactivity disorder (ADHD). However, little is known about the neural correlates of these two functions after chronic treatment with atomoxetine. This study aimed to use the counting Stroop task with functional magnetic resonance imaging (fMRI) and the Cambridge Neuropsychological Test Automated Battery (CANTAB) to investigate the changes related to inhibitory control and visual processing in adults with ADHD. This study is an 8-week, placebo-controlled, double-blind, randomized clinical trial of atomoxetine in 24 drug-naïve adults with ADHD. We investigated the changes of treatment with atomoxetine compared to placebo-treated counterparts using the counting Stroop fMRI and two CANTAB tests: rapid visual information processing (RVP) for inhibitory control and delayed matching to sample (DMS) for visual processing. Atomoxetine decreased activations in the right inferior frontal gyrus and anterior cingulate cortex, which were correlated with the improvement in inhibitory control assessed by the RVP. Also, atomoxetine increased activation in the left precuneus, which was correlated with the improvement in the mean latency of correct responses assessed by the DMS. Moreover, anterior cingulate activation in the pre-treatment was able to predict the improvements of clinical symptoms. Treatment with atomoxetine may improve inhibitory control to suppress interference and may enhance the visual processing to process numbers. In addition, the anterior cingulate cortex might play an important role as a biological marker for the treatment effectiveness of atomoxetine. Hum Brain Mapp 38:4850-4864, 2017. © 2017 Wiley Periodicals, Inc.

Combined methylphenidate and atomoxetine pharmacotherapy in attention deficit hyperactivity disorder

OBJECTIVES

Pharmacological treatment of attention deficit hyperactivity disorder (ADHD) includes stimulant and non-stimulant medications. Our purpose in this study is to investigate efficacy, safety and tolerability of combined methylphenidate and atomoxetine pharmacotherapy.

METHODS

We included 12 patients of the 824 patients with ADHD using methylphenidate and atomoxetine combined therapy between the years 2010 and 2014. Kiddie-SADS, Turgay DSM-IV Based Child and Adolescent Behavior Disorders Screening and Rating Scale, Child Behavior Checklist, Clinic Global Impression Scale Severity and Impression (CGIS-S-I) scales were used.

RESULTS

Patients were between the ages of 7 and 17 years. Before combined pharmacotherapy the CGIS-S score mean was 5.08. Mean CGIS-S score after the combined pharmacotherapy was 3.08 (P = 0.03; -2,980). The most common side effects were irritability (n = 5, 41.6%), appetite reduction (n = 3, 25%), palpitations (n = 2, 16.7%), headache (n = 1, 8.3%).

CONCLUSIONS

Nine of these 12 patients showed significant improvement in their symptoms, combined therapy enhanced the effectiveness of monotherapy.

Development of a refill pattern method to measure polypharmacy in administrative claims databases

PURPOSE

The purposes of the study were to develop a refill pattern method to identify polypharmacy in pharmacy billing records and to compare the method with traditional days' supply overlap algorithms.

METHODS

This method is characterized by the assessment of prescription refill pattern. Concomitant therapy is assumed when two drugs are dispensed repeatedly during the active days' supply of each other. We tested the refill pattern method in a simplified scenario in which two drugs (methylphenidate/dexmethylphenidate and atomoxetine) for attention deficit/hyperactivity disorder (ADHD) were considered. Children who had at least one prescription of methylphenidate/dexmethylphenidate or atomoxetine in 2008 were included for the calculation of 2-year prevalence of ADHD treatment polypharmacy. Results were compared with traditional method that requires a minimum overlap of 30, 60 or 90 days of filled prescriptions. We compared polypharmacy prevalence estimated by the two methods and explored reasons for disagreement.

RESULTS

Among 131 385 children who had at least one prescription of methylphenidate/dexmethylphenidate or atomoxetine, the refill pattern method identified 4021 patients who had ADHD treatment polypharmacy (2-year prevalence = 3.1%). This prevalence estimate fell between those from a 30- to 60-day overlap method. The Cohen's kappa regarding determination of polypharmacy was 0.83, 0.92 and 0.80 considering 90-, 60- and 30-day overlap method, respectively.

CONCLUSIONS

The refill pattern method can be used as another way to measure polypharmacy in administrative claims databases and can be adapted to a wide variety of research questions, diseases and study populations. Copyright © 2016 John Wiley & Sons, Ltd.

Initiation and Persistence of Pharmacotherapy for Youths with Attention Deficit Hyperactivity Disorder in Taiwan

BACKGROUND

Pharmacotherapy is an effective therapeutic option for attention deficit hyperactivity disorder (ADHD). Understanding the patterns of medication treatment is crucial for clinical practice. This study employed nationwide population-based data to elucidate the initiation and persistence of pharmacotherapy (immediate-release methylphenidate [IR-MPH], osmotic controlled-release formulations of methylphenidate [OROS-MPH] and atomoxetine [ATX]) for youths with ADHD in Taiwan.

METHODS

Patients first receiving an ADHD diagnosis at age 18 or younger between January 2000 and December 2009 (n = 112,140; mean age at ADHD diagnosis: 7.7 years) were selected from Taiwan's National Health Insurance database. All patients were monitored through December 31, 2011, with an average follow-up time of 5.8 years. The initiation of ADHD drug therapy was defined as the first patient prescription, and discontinuation was defined as the cessation of ADHD medication for 180 days or longer.

RESULTS

Within the first year after ADHD diagnosis, 47.3%, 14.4%, and 0.8% of the patients were prescribed IR-MPH, OROS-MPH, and ATX, respectively. Regarding the patients prescribed IR-MPH, OROS-MPH, and ATX, 17.8%, 12.6%, and 18.8%, respectively, received the prescription only once and never returned for a drug refill, and 51.0%, 38.9%, and 58.8%, respectively, discontinued drug therapy within 1 year after the first prescription. Male sex and neuropsychiatric comorbidities were associated with higher probabilities of being prescribed one of the medications. An older age at first prescription and a higher daily dose of prescription were significant predictors of early discontinuation of ADHD medication.

CONCLUSIONS

The current findings suggest that IR-MPH is the most frequently prescribed drug for ADHD treatment in Taiwan. Patients treated with OROS-MPH possessed the highest persistence rate, whereas those treated with ATX had the lowest persistence rate. The results provide insight into the delivery of pediatric mental health services and have crucial implications for ADHD medication treatment in real clinical settings.

Attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a persistent neurodevelopmental disorder that affects 5% of children and adolescents and 2.5% of adults worldwide. Throughout an individual's lifetime, ADHD can increase the risk of other psychiatric disorders, educational and occupational failure, accidents, criminality, social disability and addictions. No single risk factor is necessary or sufficient to cause ADHD. In most cases ADHD arises from several genetic and environmental risk factors that each have a small individual effect and act together to increase susceptibility. The multifactorial causation of ADHD is consistent with the heterogeneity of the disorder, which is shown by its extensive psychiatric co-morbidity, its multiple domains of neurocognitive impairment and the wide range of structural and functional brain anomalies associated with it. The diagnosis of ADHD is reliable and valid when evaluated with standard criteria for psychiatric disorders. Rating scales and clinical interviews facilitate diagnosis and aid screening. The expression of symptoms varies as a function of patient developmental stage and social and academic contexts. Although there are no curative treatments for ADHD, evidenced-based treatments can markedly reduce its symptoms and associated impairments. For example, medications are efficacious and normally well tolerated, and various non-pharmacological approaches are also valuable. Ongoing clinical and neurobiological research holds the promise of advancing diagnostic and therapeutic approaches to ADHD. For an illustrated summary of this Primer, visit: http://go.nature.com/J6jiwl.

Effects of the combination of wheel running and atomoxetine on cue- and cocaine-primed reinstatement in rats selected for high or low impulsivity

BACKGROUND

Aerobic exercise and the attention-deficit/hyperactivity disorder medication, atomoxetine (ATO), are two monotherapies that have been shown to suppress reinstatement of cocaine-seeking in an animal model of relapse. The present study investigated the effects of combining wheel running and ATO versus each treatment alone on cocaine-seeking precipitated by cocaine and cocaine-paired cues in rats with differing susceptibility to drug abuse (i.e., high vs. low impulsive).

METHODS

Rats were screened for high (HiI) or low impulsivity (LoI) based on their performance on a delay-discounting task and then trained to self-administer cocaine (0.4 mg/kg/inf) for 10 days. Following 14 days of extinction, both groups were tested for reinstatement of cocaine-seeking precipitated by cocaine or cocaine-paired cues in the presence of concurrent running wheel access (W), pretreatment with ATO, or both (W+ATO).

RESULTS

HiI rats acquired cocaine self-administration more quickly than LoI rats. While both individual treatments and W+ATO significantly attenuated cue-induced cocaine seeking in HiI and LoI rats, only W+ATO was effective in reducing cocaine-induced reinstatement compared with vehicle treatment. There were dose-dependent and phenotype-specific effects of ATO with HiI rats responsive to the low but not high ATO dose. Floor effects of ATO and W on cue-induced reinstatement prevented the assessment of combined treatment effects.

CONCLUSIONS

These findings demonstrated greater attenuation of cue- versus cocaine-induced reinstatement by ATO and W alone and recapitulate impulsivity phenotype differences in both acquisition of cocaine self-administration and receptivity to treatment.

Canadian guidelines on pharmacotherapy for disruptive and aggressive behaviour in children and adolescents with attention-deficit hyperactivity disorder, oppositional defiant disorder, or conduct disorder

OBJECTIVE

To develop evidence-based guidelines on pharmacotherapy for severe disruptive and aggressive behaviour in children and adolescents with attention-deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), or conduct disorder (CD). The guidelines assume that psychosocial interventions have been pursued but did not achieve sufficient improvement.

METHOD

A multidisciplinary consensus group used the Grading of Recommendations Assessment, Development and Evaluation approach for rating evidence quality and for grading recommendations. We conducted a systematic review of medications studied in placebo-controlled trials for treating disruptive and aggressive behaviour in children and adolescents with ADHD, ODD, or CD. We followed consensus procedures to make 1 of 4 recommendations for each medication: strong, in favour (↑↑); conditional, in favour (↑?); conditional, against (↓?); and strong, against (↓↓).

RESULTS

For children and adolescents with disruptive or aggressive behaviour associated with ADHD, psychostimulants received a strong recommendation in favour of use, while atomoxetine and alpha-2 agonists received a conditional recommendation in favour of use. If these patients do poorly with ADHD medications, the medication with the most evidence is risperidone. Risperidone also has the most evidence for treating disruptive or aggressive behaviour in the absence of ADHD. However, given risperidone's major adverse effects, it received only a conditional recommendation in favour of use. We recommended against using quetiapine, haloperidol, lithium, or carbamazepine because of the poor quality of evidence and their major adverse effects.

CONCLUSION

When severe disruptive or aggressive behaviour occurs with ADHD, medications for ADHD should be used first. Other medications have major adverse effects and, with the exception of risperidone, very limited evidence to support their use.

Genetic targeting of the amphetamine and methylphenidate-sensitive dopamine transporter: on the path to an animal model of attention-deficit hyperactivity disorder

Alterations in dopamine (DA) signaling underlie the most widely held theories of molecular and circuit level perturbations that lead to risk for attention-deficit hyperactivity disorder (ADHD). The DA transporter (DAT), a presynaptic reuptake protein whose activity provides critical support for DA signaling by limiting DA action at pre- and postsynaptic receptors, has been consistently associated with ADHD through pharmacological, behavioral, brain imaging and genetic studies. Currently, the animal models of ADHD exhibit significant limitations, stemming in large part from their lack of construct validity. To remedy this situation, we have pursued the creation of a mouse model derived from a functional nonsynonymous variant in the DAT gene (SLC6A3) of ADHD probands. We trace our path from the identification of these variants to in vitro biochemical and physiological studies to the production of the DAT Val559 mouse model. We discuss our initial findings with these animals and their promise in the context of existing rodent models of ADHD.