Switching from neurostimulant therapy to atomoxetine in children and adolescents with attention-deficit hyperactivity disorder : clinical approaches and review of current available evidence

This review provides practical information on and clinical reasons for switching children and young people with attention-deficit hyperactivity disorder (ADHD) from neurostimulants to atomoxetine, detailing currently available evidence, and switching options. The issue is of particular relevance following recent guidance from the National Institute for Health and Clinical Excellence and European ADHD guidelines endorsing the use of atomoxetine, along with the stimulants methylphenidate and dexamphetamine, in the management of ADHD in children and adolescents in the UK. The selective norepinephrine (noradrenaline) reuptake inhibitor, atomoxetine, is a non-stimulant drug licensed for the treatment of ADHD in children and adolescents, and in adults who have shown a response in childhood. Following the once-daily morning dose, its therapeutic effects extend through the waking hours, into late evening, and in some patients, through to early the next morning. Atomoxetine may be considered for patients who are unresponsive or incompletely responsive to stimulant treatment, have co-morbid conditions (e.g. tics, anxiety, depression), and have sleep disturbances or eating problems, for patients in whom stimulants are poorly tolerated, and for situations where there is potential for drug abuse or diversion. Atomoxetine has been shown to be effective in relapse prevention and there is suggestion that atomoxetine may have a positive effect on global functioning; specifically health-related quality of life, self-esteem, and social and family functioning. According to one study, approximately 50% of non-responders to methylphenidate will respond to atomoxetine therapy and approximately 75% of responders to methylphenidate will also respond to atomoxetine. Atomoxetine may be initiated by a schedule of dose increases and cross-tapering with methylphenidate. A slow titration schedule with divided doses minimizes the impact of adverse events within the first several weeks of treatment. Atomoxetine may be co-administered with methylphenidate during the switching period without undue concern for adverse events, such as cardiovascular effects (although monitoring of blood pressure and heart rate is necessary). Atomoxetine may be discontinued abruptly and patients may miss the occasional dose without rebound effects or discontinuation syndrome. A trial period of at least 6-8 weeks, perhaps longer, is recommended before evaluation of the overall tolerability and efficacy of atomoxetine. We conclude that patients with ADHD can be switched from neurostimulants, specifically methylphenidate, to atomoxetine, and may benefit from symptom improvement.     

Long-term outcomes with medications for attention-deficit hyperactivity disorder: current status of knowledge

Attention-deficit hyperactivity disorder (ADHD), a common neurobehavioural disorder characterized by inattention, hyperactivity and impulsivity, is a chronic disorder and often persists into adulthood. CNS stimulants have been the most well known treatment for ADHD for several decades due to their high effectiveness, good safety profiles and relatively minor adverse effects. Non-stimulant agents, including atomoxetine, extended-release guanfacine and extended-release clonidine (US FDA approved), and several non-FDA-approved agents, such as bupropion and tricyclic antidepressants (TCAs), were recently proven to be effective alternatives to the stimulants in several open-label and placebo-controlled trials. However, most medication trials for ADHD have been short term and thus have not provided information on the long-term outcomes of ADHD treatment. Since the medical treatment of many children with ADHD, especially those with more severe symptoms or co-morbid disorders, has to be continued for several years, recent studies have shifted their focus from the acute effectiveness of stimulants or non-stimulant drugs to the long-term outcomes of medications for ADHD. Evidence has shown that stimulants, along with the non-stimulants atomoxetine and extended-release guanfacine, are continuously effective for 24-month treatment periods with few and tolerable adverse effects.     

Effectiveness of one-year pharmacological treatment of adult attention-deficit/hyperactivity disorder (ADHD): An open-label prospective study of time in treatment,dose, side-effects and comorbidity

How to generalize from randomized placebo controlled trials of ADHD drug treatment in adults to ‘real-world’ clinical practice is intriguing. This open-labeled prospective observational study examined the effectiveness of long-term stimulant and non-stimulant medication in adult ADHD including dose, side-effects and comorbidity in a clinical setting.A specialized ADHD outpatient clinic gave previously non-medicated adults (n=250) with ADHD methylphenidate as first-line drug according to current guidelines. Patients who were non-tolerant or experiencing low efficacy were switched to amphetamine or atomoxetine. Primary outcomes were changes of ADHD-symptoms evaluated with the Adult ADHD Self-Report Scale (ASRS) and overall severity by the Global Assessment of Functioning (GAF). Secondary outcomes were measures of mental distress, and response on the Clinical-Global-Impressions-Improvement Scale. Data at baseline and follow-ups were compared in longitudinal mixed model analyses for time on-medication, dosage, comorbidity, and side-effects.As results, 232 patients (93%) completed examination at the 12 month endpoint, and 163 (70%) remained on medication. Compared with the patients who discontinued medication, those still on medication had greater percentage reduction in ASRS-scores (median 39%, versus 13%, P<0.001) and greater improvement of GAF (median 20% versus 4%, P<0.001) and secondary outcomes. Continued medication and higher cumulated doses showed significant associations to sustained improvement. Conversely, psychiatric comorbidity and side-effects were related to lower effectiveness and more frequent termination of medication.Taken together, one-year treatment with stimulants or atomoxetine was associated with a clinically significant reduction in ADHD symptoms and mental distress, and improvement of measured function. No serious adverse events were observed.     

Pharmacological treatment and demographic characteristics of pediatric patients with Attention Deficit Hyperactivity Disorder,Sweden

The aim of this study was to describe the pediatric population with ADHD and their pharmacological treatment. Using the Swedish National Patient Register and the Prescribed Drug Register we identified individuals below 19 years of age who were diagnosed or medically treated for ADHD for the first time 2006–2007. The unique patient identifiers were used to link information from the two registers to describe demographic characteristics, hospital care and drug treatments. Logistic regression model estimated the association between age, sex, frequency of hospitalization, diagnosis or treatment for other mental disorders and risk of gap in the treatment. Totally the study included 7931 patients of whom 74% were males. The mean age at first diagnosis was 12 years. Some 84% were medically treated for ADHD and approximately 90% received methylphenidate as the first substance. Combination therapy was rare and the most common combination was methylphenidate and atomoxetine. More than 55% of the patients, which could be followed up for two years after start of treatment, had at least one treatment gap of six months. Older age at diagnosis, lower number of hospitalizations and comorbidity with other mental disorders increased risks of gaps in medication. Approximately one fifth of the patients recorded in the National Patient Register as diagnosed with ADHD did not receive pharmacological treatment. Medication adherence seems to be low, when measured as gaps in treatment.     

A treatment algorithm for attention deficit hyperactivity disorder in cocaine‐dependent adults: A one‐year private practice study with long‐acting stimulants,fluoxetine, and bupropion

A subgroup of adults in private treatment for cocaine dependence in remission reported a therapeutic effect from cocaine during the initial phases of cocaine addiction and, also, met DSM‐IV criteria for ADHD. We report evidence that study subjects probably medicated their ADHD symptoms with cocaine and describe a 1‐year treatment algorithm featuring long‐acting stimulants that was effective in the management of their ADHD and cocaine dependence. Nineteen stable patients in full remission from all substance dependence were entered into an open label, prospective, treatment trial for ADHD. The treatment schedule consisted of the progressive introduction—and discontinuation of ineffective medication—of each of several medications in the following order: fluoxetine, bupropion, pemoline, sustained‐release methylphenidate, dextroamphetamine spansules, and methamphetamine gradumets. Treatment of ADHD was successful. Several treatment regimens, especially those including long‐acting stimulants, alone or in combination with other agents, were highly effective. All but 1 of the 19 subjects had a fully effective response for at least 1 full year. Mean UTAH scale scores were 7.4 before any medications were administered and 1.6 at the end of the study. Treatment proved successful in suppressing ADHD symptoms, with minimal cocaine slips or side effects.     

Comparative benefits and harms of competing medications for adults with attention-deficit hyperactivity disorder: a systematic review and indirect comparison meta-analysis

Rationale Recommended medication prescribing hierarchies for adult attention-deficit hyperactivity disorder (ADHD) vary between different guideline committees. Few trials directly compare competing ADHD medications in adults and provide little insight for clinicians making treatment choices. Objective The objective of this study was to assess comparative benefits and harms of competing medications for adult ADHD using indirect comparison meta-analysis. Materials and methods Eligible studies were English-language publications of randomized controlled trials comparing ADHD drugs to placebo. Data sources were electronic bibliographic databases, Drugs@FDA, manufacturer data, and reference lists. Two reviewers independently abstracted data on design, internal validity, population, and results. Benefits and harms were compared between drug types using indirect comparison meta-regression (ratio of relative risks). Results Twenty-two placebo-controlled trials were included (n = 2,203). Relative benefit of clinical response for shorter-acting stimulants, primarily immediate release methylphenidate, was 3.26 times greater than for patients taking longer-acting stimulants (95% CI 2.03, 5.22) and 2.24 times greater than for patients taking longer-acting forms of bupropion (95% CI 1.23, 4.08). Immediate release methylphenidate is also the only drug shown to reduce ADHD symptoms in adults with substance abuse disorders. Neither non-stimulants nor longer-acting stimulants reduced adverse effects compared to shorter-acting stimulants. Key gaps in evidence were academic, occupational, social functioning, cardiovascular toxicity, and longer-term outcomes, influences of ADHD subtype and/or comorbidities, and misuse/diversion of the drugs. Conclusions Current best evidence supports using immediate release methylphenidate as first-line treatment for most adults with ADHD. Financial disclosures None of the authors or the person named in the Acknowledgments section have any financial interest in any company that makes or distributes the products reviewed in this report.     

Substance abuse in patients with attention-deficit hyperactivity disorder : therapeutic implications

Attention-deficit hyperactivity disorder (ADHD) is a common disorder in children that frequently persists into adulthood. Studies have found that substance use disorders (SUD) are seen more commonly in those with ADHD than the general population. Although treatment with stimulant medications has been shown to be effective for individuals with ADHD, concern about the use of these agents in this population persists. This review article highlights the research in this area with a focus on the treatment of individuals who present with concomitant ADHD and SUD. Although stimulants can be abused, studies have shown that adolescents who are prescribed stimulants for ADHD have lower rates of SUD than those who are not treated with stimulants. It may be particularly difficult to evaluate adults for the diagnosis of ADHD when SUD is a co-morbid factor. Studies show that 20--30% of adults presenting with SUD have concomitant ADHD and approximately 20--40% of adults with ADHD have histories of SUD. Therefore, it is critical to perform careful diagnostic interviews to discern if patients have either or both of these disorders. Many clinical experts suggest that adults with ADHD and active SUD be treated for the SUD until a period of sobriety persists prior to initiation of specific treatment for ADHD. Since individuals with ADHD and active SUD are more likely to have more severe SUD and a worse prognosis, this approach may not serve many patients, as they relapse prior to obtaining ADHD treatment. Therefore, research has been directed towards determining if the treatment of ADHD with stimulant medications can be safe and effective for the individual with active SUD and concomitant ADHD. An initial trial of methylphenidate in a population of adults with active cocaine dependence and ADHD indicates that this is the case. Individuals with ADHD and SUD can present difficult diagnostic and therapeutic challenges. It appears that the most effective treatment option is to create a programme that uses the most effective treatment modalities available, including both behavioural and medical therapies, along with close supervision and monitoring. Newer medical treatment options of long-acting stimulants and non-stimulants (e.g. atomoxetine) offer effective treatment with a lower risk of abuse potential.     

Discriminative-stimulus, self-reported, performance, and cardiovascular effects of atomoxetine in methylphenidate-trained humans

Atomoxetine is marketed as a nonstimulant medication indicated for the treatment of attention-deficit/hyperactivity disorder in adults. Previous laboratory research suggests that atomoxetine has limited abuse potential but that some of its behavioral effects might overlap with traditional psychomotor stimulants like methylphenidate and d-amphetamine. A drug with this profile might be useful for the treatment of stimulant dependence. The aim of this experiment was to compare the discriminative-stimulus and self-reported effects of atomoxetine with methylphenidate, damphetamine, and triazolam in humans who had acquired a methylphenidate (30 mg) discrimination. Six healthy subjects with a recent history of nontherapeutic stimulant use were enrolled in this outpatient study. After subjects acquired the methylphenidate discrimination, a range of doses of methylphenidate (5-30 mg), atomoxetine (15-90 mg), d-amphetamine (2.5-15 mg), triazolam (0.06-0.375 mg), and placebo were tested. To more fully characterize the behavioral effects of atomoxetine, a battery of self-reported drug-effect questionnaires, a performance task, and cardiovascular assessments were also included. Methylphenidate and d-amphetamine increased drug-appropriate responding and produced typical stimulant-like effects (e.g., increased ratings of "Active, Alert, Energetic"). Atomoxetine partially substituted for methylphenidate (i.e., 33%-50%) and produced some dose-dependent, stimulant-like, subject-rated drug effects, although the magnitude of these effects was less than d-amphetamine and methylphenidate and generally did not attain statistical significance. These data suggest that the behavioral effects of atomoxetine overlap to a small degree with psychomotor stimulants and that it has low abuse potential.     

Atomoxetine: the first nonstimulant for the management of attention-deficit/hyperactivity disorder.

PURPOSE: The pharmacology, pharmacokinetics, clinical efficacy, safety, drug interactions, dosage and administration, and place in therapy of atomoxetine in the treatment of attention-deficit/hyperactivity disorder (ADHD) are reviewed. SUMMARY: Atomoxetine is a methylphenoxy-benzenepropanamine derivative with antidepressant activity and is thought to enhance noradrenergic function via selective inhibition of the presynaptic norepinephrine transporter. Atomoxetine is rapidly absorbed from the gastrointestinal tract, reaching peak levels in 1.83 hours in pediatric patients and 1-1.5 hours in adults. The clinical efficacy of atomoxetine in the treatment of ADHD has been evaluated in six published clinical trials of children and adolescents and two studies enrolling only adults. Clinical trial data indicate that atomoxetine is safe and well tolerated for the treatment of ADHD; however, safety data about long-term use (greater than one year) are unavailable. Adverse events reported in clinical trials were mainly mild to moderate and transient in nature. Recommended dosing of atomoxetine is weight based, and dosages should be adjusted to a target dosage of 1.2 mg/kg/day in children and adolescents weighing 70 kg or less and to 80 mg/day in children and adolescents weighing over 70 kg and adults. While current guidelines from the American Academy of Pediatrics recommend stimulants and behavior modification as first-line therapy for the management of ADHD, atomoxetine offers those patients who do not respond to or cannot tolerate one or more stimulants an alternative treatment option. CONCLUSION: Atomoxetine, the first non-stimulant approved for the management of ADHD in children, adolescents, and adults, provides patients who have not responded to or cannot tolerate one or more stimulants an alternative treatment option.     

Current issues around the pharmacotherapy of ADHD in children and adults

Background New drugs and new formulations enter the growing market for ADHD medication. The growing awareness of possible persistence of ADHD impairment beyond childhood and adolescence resulting in increased pharmacotherapy of ADHD in adults, is also a good reason for making an inventory of the what is generally known about pharmacotherapy in ADHD. Aim To discuss current issues in the possible pharmacotherapy treatment of ADHD in children, adolescents and adults with respect to the position of pharmacotherapy in ADHD treatment guidelines, the pharmacoepidemiological trends, and current concerns about the drugs used. Methods A search of the literature with an emphasis on the position of pharmacotherapy in ADHD treatment guidelines, the pharmacoepidemiological trends, and current concerns about the drugs used in pharmacotherapy. Results According to the guidelines, the treatment of ADHD in children consists of psychosocial interventions in combination with pharmacotherapy when needed. Stimulants are the first-choice drugs in the pharmacological treatment of ADHD in children despite a number of well known and frequently reported side effects like sleep disorders and loss of appetite. With regard to the treatment of adults, stimulant treatment was recommended as the first-choice pharmacotherapy in the single guideline available. Both in children and adults, there appears to be an additional though limited role for the nonadrenergic drug atomoxetine. The increase of ADHD medication use, in children, adolescents and in adults, can not only be interpreted as a sign of overdiagnosis of ADHD. Despite the frequent use of stimulants, there is still a lack of clarity on the effects of long-term use on growth and nutritional status of children. Cardiovascular effects of both stimulants and atomoxetine are rare but can be severe. The literature suggests that atomoxetine may be associated with suicidal ideation in children. Conclusion Although pharmacotherapy is increasing common in the treatment of ADHD in both children and adults, there are still a lot of questions about side effects and how best to counter them. This suggests an important role for close monitoring of children and adults treated with stimulants or atomoxetine.     

Long-term efficacy and safety of treatment with stimulants and atomoxetine in adult ADHD: A review of controlled and naturalistic studies

Attention-deficit/hyperactivity disorder (ADHD) is a common disorder of childhood that often persists into adulthood. Although stimulant medications are recommended as the first-line treatment for ADHD because of their documented short-term effects in children and adults, less is known about their effects on long-term outcome in adults. Here we review the long-term efficacy and safety of the stimulant drugs methylphenidate and amphetamine, as well as the related compound atomoxetine. We performed a systematic review to identify direct and indirect effects of stimulant therapy on long-term outcome in adults. Five randomized controlled trials (RCTs), and 10 open-label extension studies of initial short-term RCTs, with total follow-up of at least 24 weeks, were identified. All these RCTs found that medication was significantly more efficacious than placebo in treating ADHD in adults, and the extension studies showed that this favorable effect of medication was maintained during the open-label follow-up period. However, since the maximum duration of these pharmacological trials was 4 years, we also reviewed 18 defined naturalistic longitudinal and cross-sectional studies, to provide more information about longer term functional outcomes, side effects and complications. These observational studies also showed positive correlations between early recognition of the disorder, stimulant treatment during childhood and favorable long-term outcome in adult ADHD patients. In conclusion, stimulant therapy of ADHD has long-term beneficial effects and is well tolerated. However, more longitudinal studies of long duration should be performed. In addition, the ethical issues involved in performing double blind RCTs of many years duration should be further explored.     

托莫西汀与哌甲酯治疗注意缺陷多动障碍患儿的疗效和安全性比较

目的:比较托莫西汀与哌甲酯治疗注意缺陷多动障碍患儿的疗效和安全性。方法:选择我院收治的注意缺陷多动障碍患儿共52例,随机分为托莫西汀组与哌甲酯组各26例,治疗结束后观察两组患儿的治疗有效率、ADHDRS-IV-Parent:Inv评分以及CPRS-R:S评分。结果:托莫西汀组与哌甲酯组的治疗有效率相近。治疗后托莫西汀组与哌甲酯组的ADHDRS-IV-Parent:Inv各项评分均明显下降,与治疗前比较差异均有统计学意义(P<0.05)。治疗后托莫西汀组与哌甲酯组CPRS-R:S评分的分数均明显下降,与治疗前比较差异均有统计学意义(P<0.05)。托莫西汀组的多动分变化值大于哌甲酯组,差异有统计学意义(P<0.05),两组患儿在治疗过程中均未发现严重的药物不良反应。结论:托莫西汀的疗效与哌甲酯相近,都具有良好的安全性,值得临床推广。     

Efficacy and tolerability of pharmacotherapies for attention-deficit hyperactivity disorder in adults

This review examines the evidence regarding the efficacy and tolerability of long- and short-acting stimulant medications, as well as the non-stimulant medications atomoxetine and bupropion in the treatment of adult attention-deficit hyperactivity disorder (ADHD). Effect sizes in adults appear to be of almost the same magnitude as in school-age children when robust doses are used. There are adequate data demonstrating short-term efficacy and safety of medication in ADHD during adulthood but long-term studies are lacking, particularly in view of concerns regarding cardiovascular adverse events. There is some evidence that stimulant medication can improve driving performance in adults with ADHD. The extent to which medication may improve academic, occupational and social functioning in adults with ADHD is unclear, and future research should investigate these outcomes. Medication treatment of adults with ADHD in sports is controversial. Both stimulant and non-stimulant medications seem to be well tolerated. Monitoring of pulse and blood pressure is recommended with these drugs because of their cardiovascular effects. There have been extremely rare case reports of sudden death in adults and children treated with stimulants and atomoxetine, but it is difficult to clearly establish causality. In view of reports of treatment-related suicide-related behaviour with atomoxetine, it is recommended that adults should be observed for agitation, irritability, suicidal thinking, self-harming or unusual behaviour, particularly in the first months of treatment, or after a change of dose. ADHD in adults continues to remain an under-recognized disorder in many parts of the world and there is a lack of specialist clinics for assessment and treatment of adult ADHD. Studies to date have failed to show efficacy of medications in the treatment of ADHD in the substance misuse population. There is little evidence so far to suggest an increased misuse of stimulants or diversion amongst substance misusers; however, data are insufficient to draw firm conclusions. Further work is necessary to evaluate effective treatments in subgroups such as the substance misuse population, those with multiple co-morbidities and different ADHD subtypes.     

Methylphenidate and atomoxetine normalise fronto-parietal underactivation during sustained attention in ADHD adolescents

Problems with sustained attention are a key clinical feature of Attention Deficit/Hyperactivity Disorder (ADHD) which also manifests in poor performance and abnormal fronto-striato-parietal activation during sustained attention. Methylphenidate and atomoxetine improve attention functions and upregulate abnormal fronto-cortical activation during executive function tasks in ADHD patients. Despite this, no functional Magnetic Resonance Imaging (fMRI) study has compared the effects of methylphenidate and atomoxetine on the neurofunctional substrates of sustained attention in ADHD. This randomised, double-blind, placebo-controlled, cross-over study investigated the comparative normalisation effects of methylphenidate and atomoxetine on fMRI correlates and performance in 14 ADHD adolescents relative to 27 age-matched healthy controls during a parametric sustained attention/vigilance task with progressively increasing load of sustained attention. ADHD patients were scanned three times under a single clinical dose of either methylphenidate, atomoxetine, or placebo in pseudo-randomised order. Healthy controls were scanned once and compared to patients under each drug condition to test for potential drug-normalisation effects. Relative to controls, ADHD boys under placebo were impaired in performance and had underactivation in predominantly right-hemispheric fronto-parietal, and striato-thalamic regions. Both drugs normalised all underactivations, while only methylphenidate improved performance deficits. Within patients, methylphenidate had a drug-specific effect of upregulating left ventrolateral prefrontal/superior temporal activation relative to placebo and atomoxetine, while both drugs increased activation of right middle/superior temporal cortex, posterior cingulate, and precuneus relative to placebo. The study shows shared normalisation effects of methylphenidate and atomoxetine on fronto-striato-thalamo-parietal dysfunction in ADHD during sustained attention but a drug-specific upregulation effects of methylphenidate on ventral fronto-temporal regions.