Transition from methylphenidate or amphetamine to atomoxetine in children and adolescents with attention-deficit/hyperactivity disorder--a preliminary tolerability and efficacy study

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.

A systematic review of pharmacotherapy for attention-deficit/hyperactivity disorder in children and adolescents with bipolar disorders

INTRODUCTION

The data suggests that in children and adolescents, bipolar disorder (BD) and attention deficit hyperactivity disorder (ADHD) may be strongly correlated. Even though drugs for ADHD and BD are largely accepted, there is relatively little research on the management of comorbidity in children and adolescents, particularly in terms of safety. We provide a synthesis of these findings because one hasn't been made yet.

AREAS COVERED

As a primary outcome, we wanted to determine whether stimulant or non-stimulant treatment of children and adolescents with ADHD and comorbid BD was effective. As a secondary outcome, we wanted to determine tolerability, especially the risk of mood switch.

EXPERT OPINION

The findings of this systematic review suggest that methylphenidate, when used with a mood stabilizer, may be safe and not significantly increase the risk of a manic switch or psychotic symptoms when used to treat ADHD that co-occurs with a BD. In situations where stimulants are ineffective or have low tolerance, atomoxetine also seems to be a good alternative, and also in cases of co-morbid anxiety, oppositional defiant disorder, conduct disorders, ICT disorders, and substance use disorders. Additional research with a higher level of evidence is necessary to corroborate these preliminary findings.

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.

N-methyl-d-aspartate receptor dysfunction in the prefrontal cortex of stroke-prone spontaneously hypertensive rat/Ezo as a rat model of attention deficit/hyperactivity disorder

AIM

We previously reported that stroke-prone spontaneously hypertensive rat/Ezo (SHRSP/Ezo) has high validity as an attention deficit/hyperactivity disorder (AD/HD) animal model, based on its behavioral phenotypes, such as inattention, hyperactivity, and impulsivity. Fronto-cortical dysfunction is implicated in the pathogenesis of AD/HD. In this study, we investigated prefrontal cortex (PFC) function in SHRSP/Ezo rats by electrophysiological methods and radioreceptor assay.

METHODS

We recorded excitatory postsynaptic potential in layer V pyramidal neurons in the PFC by intracellular recording method to assess synaptic plasticity in the form of long-term potentiation (LTP). We also performed N-methyl-d-aspartate acid (NMDA) receptor binding assay in the PFC and hippocampus using radiolabeled NMDA receptor antagonist [³ H]MK-801.

RESULTS

Theta-burst stimulation induced LTP in the PFC of genetic control, WKY/Ezo, whereas failed to induce LTP in that of SHRSP/Ezo. The K_d value of [³ H]MK-801 binding for NMDA receptors in the PFC of SHRSP/Ezo was higher than in the WKY/Ezo. Neither the B_max nor K_d of [³ H]MK-801 binding in the SHRSP/Ezo hippocampus was significantly different to WKY/Ezo.

CONCLUSION

These results suggest that the AD/HD animal model SHRSP/Ezo has NMDA receptor dysfunction in the PFC.

Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder: a Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies

The role of omega-3 polyunsaturated fatty acids (omega-3 or n-3 PUFAs) in the pathogenesis and treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD) is unclear. A systematic review followed by meta-analysis was conducted on: (1) randomized controlled trials (RCTs) assessing the effects of n-3 PUFAs on clinical symptoms and cognition in children and adolescent with ADHD; and (2) case-control studies assessing the levels of n-3 PUFAs in blood and buccal tissues of children and adolescents with ADHD. In seven RCTs, totalling n=534 randomized youth with ADHD, n-3 PUFAs supplementation improves ADHD clinical symptom scores (g=0.38, p<0.0001); and in three RCTs, totalling n=214 randomized youth with ADHD, n-3 PUFAs supplementation improves cognitive measures associated with attention (g=1.09, p=0.001). Moreover, children and adolescents with ADHD have lower levels of DHA (seven studies, n=412, g=-0.76, p=0.0002), EPA (seven studies, n=468, g=-0.38, p=0.0008), and total n-3 PUFAs (six studies, n=396, g=-0.58, p=0.0001). In summary, there is evidence that n-3 PUFAs supplementation monotherapy improves clinical symptoms and cognitive performances in children and adolescents with ADHD, and that these youth have a deficiency in n-3 PUFAs levels. Our findings provide further support to the rationale for using n-3 PUFAs as a treatment option for ADHD.

The Safety of Atomoxetine for the Treatment of Children and Adolescents with Attention-Deficit/Hyperactivity Disorder: A Comprehensive Review of Over a Decade of Research

Atomoxetine is a noradrenergic reuptake inhibitor prescribed for attention-deficit/hyperactivity disorder (ADHD) that first gained approval in the USA in 2002 and has been authorized in 97 countries worldwide. The aim of this paper is to comprehensively review publications that addressed one or more of seven major safety topics relevant to atomoxetine treatment of children and adolescents (aged ≥6 years) diagnosed with ADHD. While the review focuses on children and adolescents, publications in which data from patients aged >18 years and from 6 to 18 years were analyzed in the same dataset were included. Using a predefined search strategy, including agreement of two reviewers when selecting papers, reduced the potential for bias. Using this process, we identified 70 eligible papers (clinical trials, epidemiological studies, and case reports) across the seven topics. We also referred to the European Summary of Product Characteristics (SPC) and US label. We found 15 papers about suicidality, three about aggression/hostility, seven about psychosis/mania, six about seizures, seven about hepatic effects, 29 about cardiovascular effects, and 28 about growth and development. The main findings (i.e., those from the largest and most well-conducted studies/analyses) are as follows. A large register-based study of pediatric and adult patients (6818 received atomoxetine) calculated a hazard ratio of 0.96 for suicide-related events during treatment with atomoxetine, and a meta-analysis of 23 placebo-controlled studies (N = 3883), published in 2014, found no completed suicides and no statistically significant association between atomoxetine and suicidality. The frequency of aggression/hostility was not statistically significantly higher with atomoxetine, e.g., experienced by 1.6 % (N = 21/1308) of atomoxetine-treated patients versus 1.1 % (N = 9/806) of placebo-treated patients in one meta-analysis. Symptoms of psychosis and mania were mainly observed in patients with comorbid bipolar disorder/depression. Based on spontaneous reports, during a 2-year period when 2.233 million adult and pediatric patients were exposed to atomoxetine, the reporting rate for seizures was 8 per 100,000 patients. In the manufacturer's database, atomoxetine was a "probable cause" of three hepatic adverse events (AEs) (all reversible hepatitis), and 133 hepatic AEs had possible confounding factors and were "possibly related" to atomoxetine, during 4 years when atomoxetine exposure had reached about 4.3 million patients. Rare cases of severe liver injury are described in the US label and European SPC; a case requiring liver transplantation is described in the US label. In a comprehensive review of a clinical trials database (N = 8417 received atomoxetine), most pediatric patients experienced modest increases in heart rate and blood pressure, and 8-12 % experienced more pronounced changes (≥20 bpm, ≥15 to 20 mmHg). However, in three long-term analyses (≥2 years), blood pressure was within age norms, and few patients discontinued due to cardiovascular AEs. As described in the European SPC, QT interval prolongation is uncommon, e.g., in an open-label study, 1.4 % of 711 children and adolescents had prolonged QTc intervals (≥450 ms in males, ≥470 ms in females) that were not clinically significant at ≥3 years of treatment with atomoxetine. The European SPC warns about potential QT interval prolongation in patients with a personal or family history, or if atomoxetine is administered with other drugs that potentially affect the QT interval. Decreases in growth (weight and height gain) occurred and were greatest in patients of above average weight and height, but appeared to recover over 2-5 years of atomoxetine treatment. In conclusion, suicidality, aggression/hostility, psychosis, seizures, liver injuries, and prolonged QT interval are uncommon or rare in children and adolescents treated with atomoxetine, based on data from the predefined search and from the European SPC. Overall, the data that we assessed from our search do not suggest that associations exist between atomoxetine and suicidality or seizures. The data also suggest that an association may not exist between atomoxetine and aggression/hostility. While atomoxetine may affect the cardiovascular system, the data suggest these effects are not clinically significant in most patients. Reductions in growth appear to be reversible in the long term.

Switch in Therapy from Methylphenidate to Atomoxetine in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder: An Analysis of Patient Records

OBJECTIVE

The purpose of this study was to investigate therapy switching from methylphenidate (MPH) to atomoxetine (ATX) in a clinical sample of Danish children and adolescents with attention-deficit/hyperactivity disorder (ADHD); specifically, to determine the duration of MPH treatment before switching to ATX, and the reasons leading to a switch in therapy.

METHODS

We included 55 patients with ADHD who switched from first-line MPH to second-line ATX during January 01, 2012 and May 15, 2014. Patient and treatment characteristics along with clinical reasons for switching therapy were extracted from individual patients' records.

RESULTS

Mean duration of MPH treatment until switch to ATX was 11.2 months (range = 0.3-28.5 months); 36% of the patients switched within the first 6 months, 56% within the first year, and 76% within 1.5 years of initiating MPH; 24% continued MPH treatment for up to 2.5 years prior to switching. Most common reasons for switching were "adverse events" (AEs) (78%), "wish for more optimal day coverage" (24%), and "lack of efficacy" (16%). Other reasons for switching included "patient/parental request" (13%) and "noncompliance" (2%). Most common AEs leading to switch were psychiatric disorders (insomnia, aggression, tic, depression, anxiety) and decreased appetite.

CONCLUSIONS

Our findings highlight the importance of continuous evaluation of the need for prescription switch to ATX in children and adolescents treated with MPH, taking into consideration various factors including potential AEs, non-optimal day coverage, lack of efficacy, patient/parental preferences, and noncompliance. These factors should be considered, not only at the initial stage of MPH treatment but throughout the whole treatment course.

Amphetamines for attention deficit hyperactivity disorder (ADHD) in children and adolescents

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric conditions affecting children and adolescents. Amphetamines are among the most commonly prescribed medications to manage ADHD. There are three main classes of amphetamines: dexamphetamine, lisdexamphetamine and mixed amphetamine salts, which can be further broken down into short- and long-acting formulations. A systematic review assessing their efficacy and safety in this population has never been conducted.

OBJECTIVES

To assess the efficacy and safety of amphetamines for ADHD in children and adolescents.

SEARCH METHODS

In August 2015 we searched CENTRAL, Ovid MEDLINE, Embase, PsycINFO, ProQuest Dissertation and Theses, and the Networked Digital Library of Theses and Dissertations. We also searched ClinicalTrials.gov, and checked the reference lists of relevant studies and reviews identified by the searches. No language or date restrictions were applied.

SELECTION CRITERIA

Parallel-group and cross-over randomized controlled trials (RCTs) comparing amphetamine derivatives against placebo in a pediatric population (< 18 years) with ADHD.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on participants, settings, interventions, methodology, and outcomes for each included study. For continuous outcomes, we calculated the standardized mean difference (SMD) and for dichotomous outcomes we calculated the risk ratio (RR). Where possible, we conducted meta-analyses using a random-effects model. We also performed a meta-analysis of the most commonly reported adverse events in the primary studies.

MAIN RESULTS

We included 23 trials (8 parallel-group and 15 cross-over trials), with 2675 children aged three years to 17 years. All studies compared amphetamines to placebo. Study durations ranged from 14 days to 365 days, with the majority lasting less than six months. Most studies were conducted in the United States; three studies were conducted across Europe. We judged 11 included studies to be at a high risk of bias due to insufficient blinding methods, failing to account for dropouts and exclusions from the analysis, and failing to report on all outcomes defined a priori. We judged the remaining 12 studies to be at unclear risk of bias due to inadequate reporting.Amphetamines improved total ADHD core symptom severity according to parent ratings (SMD -0.57; 95% confidence interval (CI) -0.86 to -0.27; 7 studies; 1247 children/adolescents; very low quality evidence), teacher ratings (SMD -0.55; 95% CI -0.83 to -0.27; 5 studies; 745 children/adolescents; low quality evidence), and clinician ratings (SMD -0.84; 95% CI -1.32 to -0.36; 3 studies; 813 children/adolescents; very low quality evidence). In addition, the proportion of responders as rated by the Clinical Global Impression - Improvement (CGI-I) scale was higher when children were taking amphetamines (RR 3.36; 95% CI 2.48 to 4.55; 9 studies; 2207 children/adolescents; very low quality evidence).The most commonly reported adverse events included decreased appetite, insomnia/trouble sleeping, abdominal pain, nausea/vomiting, headaches, and anxiety. Amphetamines were associated with a higher proportion of participants experiencing decreased appetite (RR 6.31; 95% CI 2.58 to 15.46; 11 studies; 2467 children/adolescents), insomnia (RR 3.80; 95% CI 2.12 to 6.83; 10 studies; 2429 children/adolescents), and abdominal pain (RR 1.44; 95% CI 1.03 to 2.00; 10 studies; 2155 children/adolescents). In addition, the proportion of children who experienced at least one adverse event was higher in the amphetamine group (RR 1.30; 95% CI 1.18 to 1.44; 6 studies; 1742 children/adolescents; low quality evidence).We performed subgroup analyses for amphetamine preparation (dexamphetamine, lisdexamphetamine, mixed amphetamine salts), amphetamine release formulation (long acting versus short acting), and funding source (industry versus non industry). Between-group differences were observed for proportion of participants experiencing decreased appetite in both the amphetamine preparation (P < 0.00001) and amphetamine release formulation (P value = 0.008) subgroups, as well as for retention in the amphetamine release formulation subgroup (P value = 0.03).

AUTHORS' CONCLUSIONS

Most of the included studies were at high risk of bias and the overall quality of the evidence ranged from low to very low on most outcomes. Although amphetamines seem efficacious at reducing the core symptoms of ADHD in the short term, they were associated with a number of adverse events. This review found no evidence that supports any one amphetamine derivative over another, and does not reveal any differences between long-acting and short-acting amphetamine preparations. Future trials should be longer in duration (i.e. more than 12 months), include more psychosocial outcomes (e.g. quality of life and parent stress), and be transparently reported.

A critical appraisal of atomoxetine in the management of ADHD

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder beginning in childhood and often continuing into adulthood. A wealth of data shows that ADHD symptoms respond well to pharmacological treatment. Stimulant medications, including amphetamine and methylphenidate, are most commonly used to treat ADHD. However, with the approval of atomoxetine (Strattera^®, [ATX]) by the US Food and Drug Administration in late 2002, an effective non-stimulant option became available. The US Food and Drug Administration approved ATX for the treatment of ADHD in children, adolescents, and adults. Although the effect size of ATX is generally lower than that of stimulants, the American Academy of Child and Adolescent Psychiatry Practice Parameter for the treatment of ADHD lists ATX as a first-line treatment option. ATX is widely prescribed and accounted for 6% of the prescriptions of ADHD visits in the US in 2010. Numerous trials have found that ATX improves quality of life and emotional lability in addition to core ADHD symptoms. Although some improvement may be seen in a patient as early as one week after the initiation of treatment, ATX generally takes longer to have a full effect. The median time to response using 25% improvement in ADHD symptoms in pooled trials was 3.7 weeks. Data from these trials indicate that the probability of symptom improvement may continue to increase up to 52 weeks after treatment is initiated. ATX has been shown to be safe and effective in combination with stimulants. It has also been studied systematically in subjects with ADHD and comorbid oppositional defiant disorder, anxiety, depression, and substance use disorders. The mechanism of action of ATX, its efficacy, and adverse events reported in trials is reviewed.

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.

The efficacy of atomoxetine for the treatment of children and adolescents with attention-deficit/hyperactivity disorder: a comprehensive review of over a decade of clinical research

Atomoxetine was first licensed to treat attention-deficit/hyperactivity disorder (ADHD) in children and adolescents in the US in 2002. The aim of this paper is to comprehensively review subsequent publications addressing the efficacy of atomoxetine in 6- to 18-year-olds with ADHD. We identified 125 eligible papers using a predefined search strategy. Overall, these papers demonstrate that atomoxetine is an effective treatment for the core ADHD symptoms (effect sizes 0.6-1.3, vs. placebo, at 6-18 weeks), and improves functional outcomes and quality of life, in various pediatric populations with ADHD (i.e., males/females, patients with co-morbidities, children/adolescents, and with/without prior exposure to other ADHD medications). Initial responses to atomoxetine may be apparent within 1 week of treatment, but can take longer (median 23 days in a 6-week study; n=72). Responses often build gradually over time, and may not be robust until after 3 months. A pooled analysis of six randomized placebo-controlled trials (n=618) indicated that responses at 4 weeks may predict response at 6-9 weeks, although another pooled analysis of open-label data (n=338) suggests that the probability of a robust response to atomoxetine [≥40% decrease in ADHD-Rating Scale (ADHD-RS) scores] may continue to increase beyond 6-9 weeks. Atomoxetine may demonstrate similar efficacy to methylphenidate, particularly immediate-release methylphenidate, although randomized controlled trials are generally limited by short durations (3-12 weeks). In conclusion, notwithstanding these positive findings, before initiating treatment with atomoxetine, it is important that the clinician sets appropriate expectations for the patient and their family with regard to the likelihood of a gradual response, which often builds over time.

Considerations and evidence for an ADHD outcome measure

OBJECTIVE

The 2011 American Academy of Pediatrics attention-deficit/hyperactivity disorder (ADHD) guideline emphasizes monitoring and measuring outcomes of children diagnosed with ADHD; however, recommendations for how to measure improvement are less clear. A long-term goal was to develop an outcome measure that assesses the quality of care for children with ADHD. As a first step in that process, we conducted a literature synthesis on the efficacy and effectiveness of guideline-recommended ADHD treatments on patient outcomes.

METHODS

A literature search was conducted in PubMed according to PRISMA protocol and using MeSH terms. US Preventive Services Task Force (USPSTF) criteria were used to assess the level of evidence. Studies of interest were published after 2002 and assessed prospective ADHD improvement using recommended ADHD treatments.

RESULTS

The systematic review resulted in 35 studies. According to USPSTF criteria, included studies were level I (n = 24), level II-1 (n = 1), and level II-2 (n = 10) and were rated as good (n = 20) or fair (n = 15). DSM-criteria-based rating scales were used most frequently to measure ADHD treatment outcomes. All included treatments resulted in ADHD improvement. Regardless of outcome measure, tool, or treatment type, symptom reduction and improvement were relatively large, with mean percentage reductions ranging from 20% to 86% on ADHD-Behavior Rating Scales scales, with only 1 study with <25% reduction. Effect sizes ranged from 0.15 to 4.57.

CONCLUSIONS

On the basis of this literature review, a consistent pattern of improvement in pediatric ADHD patients' core symptoms emerged across studies, study designs, and recommended treatment approaches. This evidence supports the notion that an improvement of core symptoms within 1 year could satisfy the requirements of an effective outcome measure, which should be further investigated.

Fast vs. slow switching from stimulants to atomoxetine in children and adolescents with attention-deficit/hyperactivity disorder

OBJECTIVE

To compare fast versus slow switching from stimulants to atomoxetine (ATX) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

METHODS

This was a randomized, controlled, open-label study in 6-16-year-old ADHD patients, previously treated with stimulants and cross-titrated (fast switch, over 2 weeks, or slow switch, over 10 weeks) to ATX because of unsatisfactory response and/or adverse events. Study duration was 14 weeks with an ATX standard target dose of 1.2 mg/kg/day. Primary measure was the change from baseline in the investigator-rated ADHD-Rating Scale (ADHD-RS) at weeks 2 and 10. Secondary measures included Global Impression of Perceived Difficulties (GIPD) and Child Health and Illness Profile-Child Edition (CHIP-CE).

RESULTS

The majority of the 111 patients were male (83.8%, n=93) and mean (SD) age was 11.5 (2.38) years. Mean baseline ADHD-RS total score was 36.0 in the fast and 38.0 in the slow group. Adjusted mean change after 2 weeks was -8.1 (-10.1; -6.1) in the fast and -8.0 (-9.9;-6.0) in the slow group (p=0.927), and after 10 weeks -15.0 (-17.4;-12.6) and -14.3 (-16.7;-12.0), respectively, (p=0.692). GIPD scores did not show differences between groups. Significant differences at week 10 were found in the CHIP-CE achievement domain favoring slow (p=0.036) and the comfort domain favoring fast cross-titration (p=0.030). No significant differences were found for adverse events, and differences for systolic blood pressure (BP) and weight were not considered clinically relevant.

CONCLUSIONS

ADHD-RS and GIPD scores improved in both switching groups. No clinically relevant differences between fast and slow switching from stimulants to ATX were found.

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

OBJECTIVE

The purpose of this article was to systematically review the literature on stimulant and atomoxetine combination therapy, in particular: 1) Characteristics of patients with attention-deficit/hyperactivity disorder (ADHD) given combination therapy, 2) treatment strategies used, 3) efficacy and effectiveness, and 4) safety and tolerability.

METHODS

Literature databases (MEDLINE(®), EMBASE, Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, and SciVerse Scopus) were systematically searched using prespecified criteria. Publications describing stimulant and atomoxetine combination therapy in patients with ADHD or healthy volunteers were selected for review. Exclusion criteria were comorbid psychosis, bipolar disorder, epilepsy, or other psychiatric/neurologic diseases that could confound ADHD symptom assessment, or other concomitant medication(s) to treat ADHD symptoms.

RESULTS

Of the 16 publications included for review, 14 reported findings from 3 prospective studies (4 publications), 7 retrospective studies, and 3 narrative reviews/medication algorithms of patients with ADHD. The other two publications reported findings from two prospective studies of healthy volunteers. The main reason for prescribing combination therapy was inadequate response to previous treatment. In the studies of patients with ADHD, if reported, 1) most patients were children/adolescents and male, and had a combined ADHD subtype; 2) methylphenidate was most often used in combination with atomoxetine for treatment augmentation or switch; 3) ADHD symptom control was improved in some, but not all, patients; and 4) there were no serious adverse events.

CONCLUSIONS

Published evidence of the off-label use of stimulant and atomoxetine combination therapy is limited because of the small number of publications, heterogeneous study designs (there was only one prospective, randomized controlled trial), small sample sizes, and geographic bias. Existing evidence suggests, but does not confirm, that this drug combination may benefit some, but not all, patients who have tried several ADHD medications without success.

Drug therapy of attention deficit hyperactivity disorder: current trends

Attention deficit hyperactivity disorder is a developmental disorder with an age onset prior to 7 years. Children with ADHD have significantly lower ability to focus and sustain attention and also score higher on impulsivity and hyperactivity. Stimulants, such as methylphenidate, have remained the mainstay of ADHD treatment for decades with evidence supporting their use. However, recent years have seen emergence of newer drugs and drug delivery systems, like osmotic release oral systems and transdermal patches, to mention a few. The use of nonstimulant drugs like atomoxetine and various other drugs, such as α-agonists, and a few antidepressants, being used in an off-label manner, have added to the pharmacotherapy of ADHD. This review discusses current trends in drug therapy of ADHD and highlights the promise pharmacogenomics may hold in the future.

Off-label use of atomoxetine in adults: is it safe?

Atomoxetine has been approved for the treatment of attention deficit/hyperactivity disorder in both adults and children. However, it is also being examined for several off-label uses in adults including mood disorders, eating disorders, cognitive dysfunction, and the treatment of addictions. Prior to such use it is important to examine the reported adverse events to see if this represents an appropriate level of risk. This is particularly important in the light of recent warnings from several regulatory bodies about an increase in blood pressure in a significant percentage of patients taking atomoxetine. To understand the risks a literature review was performed, and which identified the following potential problems. The first is that this drug should not be given in patients with known cardiovascular problems, and that all adult patients who receive atomoxetine should be monitored for changes in blood pressure throughout treatment. Secondly, there are several clinical situations in which atomoxetine should be closely monitored, or avoided, including patients who have a history or risk of narrow angle glaucoma, epileptic seizures, Tourette's syndrome, a history of urinary outflow obstruction, or who are pregnant or lactating. In conclusion, the current literature suggests that atomoxetine can be safely used off-label provided the above precautions are taken.

Selective norepinephrine reuptake inhibition by atomoxetine prevents cue-induced heroin and cocaine seeking

BACKGROUND

Preventing relapse to drug use is a major challenge for drug addiction treatment. We have recently shown that impulsivity predating drug-taking increases the susceptibility to relapse to cocaine seeking and that treatment with the anti-impulsivity drug atomoxetine (ATO), a selective norepinephrine re-uptake inhibitor (norepinephrine transporter), prevents relapse. Here, we investigated further the effects of ATO on cue-maintained heroin and cocaine seeking and relapse and compared these effects with those of the anti-impulsivity stimulant drug methylphenidate (MPH).

METHODS

Rats were trained to seek and self-administer cocaine or heroin under a second-order schedule of reinforcement. After acquisition of stable responding, groups of rats (n = 10-12) were treated, in a within-subject design, with either ATO or MPH (.3-3.0 mg/kg IP), and the effects on cocaine and heroin seeking were measured. The effects of ATO (.3-1.0 mg/kg) on cue-induced relapse to cocaine seeking after a 1-week period of abstinence were also studied.

RESULTS

Atomoxetine significantly decreased both cue-controlled cocaine and heroin seeking, whereas MPH had no significant effect. Atomoxetine also significantly attenuated cue-induced relapse to cocaine seeking after abstinence. The effects of ATO were selective for cue-controlled drug-seeking, because it did not affect responding in the absence of the drug-paired cue; nor did it alter responding for oral sucrose, except minimally at the highest dose, or locomotor activity.

CONCLUSIONS

Selective norepinephrine transporter inhibition by ATO might be an effective treatment for the prevention of relapse to both stimulant and opiate addiction.

Preferences related to attention-deficit/hyperactivity disorder and its treatment

OBJECTIVES

A growing body of literature has highlighted the importance of considering patient preferences as part of the medical decision-making process. The purpose of the current review was to identify and summarize published research on preferences related to attention-deficit/hyperactivity disorder (ADHD) and its treatment, while suggesting directions for future research.

METHODS

A literature search identified 15 articles that included a choice-based assessment of preferences related to ADHD.

RESULTS

The 15 studies were grouped into four categories based on preference content: preference for a treatment directly experienced by the respondent or the respondent's child; preference for general treatment approaches; preference for a specific treatment attribute or outcome; and preference for aspects of ADHD-related treatment. Preference assessment methods ranged from global single items to detailed choice-based procedures, with few studies using rigorously developed assessment methods. Respondents included patients with ADHD, clinicians, parents, teachers, and survey respondents from the general population. Factors influencing preference include treatment characteristics, effectiveness for specific symptoms, side effects, and respondent demographics. Minimal research has examined treatment preferences of adults with ADHD.

DISCUSSION

Because there is no dominant treatment known to be the first choice for all patients, ADHD is a condition for which individual preferences can play an important role when making treatment decisions for individual patients. Given the potential role of preferences in clinical decision-making, more research is needed to better understand the preferences of patients with ADHD and other individuals who are directly affected by the disorder, such as parents and teachers.

Atomoxetine in children with attention-deficit hyperactivity disorder with prior stimulant therapy: a prospective open-label study

The objective of the study is to evaluate the effectiveness and tolerability of atomoxetine in youth, ages 6-17 years with ADHD, who had a prior trial of stimulant treatment. This was a 6-week prospective open-label study of atomoxetine, dosage up to 1.4 mg/kg per day in 34 children and adolescents with DSM-IV ADHD. Primary measures of response included the ADHD Rating Scale (ADHD RS) and the Clinical Global Impression (CGI) Scale. Analyses were intention-to-treat. The treatment with atomoxetine was associated with statistical and clinical significant reduction in clinician rated ADHD RS symptoms, compared with baseline. Statistical significant improvement was attained by the second week of treatment. Fifty-six percent (N = 18) met criteria for our a priori definition of response; much or very much improved on the CGI plus more than 30% reduction in ADHD RS symptoms. In conclusion, atomoxetine was generally well tolerated; 85% of subjects completed the trial. Atomoxetine was effective and well tolerated in a 6-week open study of ADHD youth with a prior history of stimulant treatment.

Atomoxetine for the treatment of attention-deficit/hyperactivity disorder in children and adolescents: a review

OBJECTIVE

This review examines and summarizes the pharmacodynamic and pharmacokinetic properties, short- and longer-term efficacy, the moderating effect of comorbid disorders, as well as short- and long-term safety and tolerability of atomoxetine for the treatment of pediatric attention-deficit/hyperactivity disorder (ADHD).

METHODS

A systematic literature search was performed to review the extant literature on articles pertaining to the pharmacological treatment with atomoxetine in pediatric and/or adolescent ADHD.

RESULTS

There is an extensive literature on atomoxetine; over 4000 children have participated in clinical trials of atomoxetine, demonstrating its short- and longer-term efficacy. In addition, studies have examined the moderating effect of comorbid disorders on atomoxetine response, as well as atomoxetine's therapeutic potential for other psychiatric conditions. Short- and longer-term safety and tolerability continue to be reported.

CONCLUSIONS

Atomoxetine is indicated for both acute and maintenance/extended treatment of pediatric ADHD. Clinicians and families must be familiar with atomoxetine's evidence base, including its profile of clinical response and its possible effectiveness in the presence of comorbidity.

Dopamine transporter inhibition is required for cocaine-induced stereotypy

The primary mechanism by which cocaine induces stereotypy has been difficult to discern because cocaine has three high-affinity targets: the reuptake transporters for dopamine (DAT), norepinephrine, and serotonin. To dissect out the role of DAT in cocaine effects, we generated a knock-in mouse line with a cocaine-insensitive DAT (DAT-CI mice). DAT-CI mice provide a powerful tool that can directly test whether DAT inhibition is important for cocaine-induced stereotypy. We found that acute cocaine failed to produce stereotypy in DAT-CI mice. In fact, 40 mg/kg cocaine suppressed stereotypy in DAT-CI mice but produced profound stereotypy in wild-type mice. These findings suggest that DAT inhibition is necessary for cocaine-induced stereotypy. Furthermore, mechanisms independent of DAT inhibition appear to inhibit stereotypy.

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.

A pilot study for augmenting atomoxetine with methylphenidate: safety of concomitant therapy in children with attention-deficit/hyperactivity disorder

BACKGROUND

This study examined augmenting atomoxetine with extended-release methylphenidate in children whose attention-deficit/hyperactivity disorder (ADHD) previously failed to respond adequately to stimulant medication.

METHODS

Children with ADHD and prior stimulant treatment (N = 25) received atomoxetine (1.2 mg/kg/day) plus placebo. After 4 weeks, patients who were responders (n = 4) were continued on atomoxetine/placebo while remaining patients were randomly assigned to either methylphenidate (ATX/MPH) (1.1 mg/kg/day) or placebo augmentation (ATX/PB) for another 6 weeks. Patients and sites were blind to timing of active augmentation. Safety measures included vital signs, weight, and adverse events. Efficacy was assessed by ADHD rating scales.

RESULTS

Categorical increases in vital signs occurred for 5 patients (3 patients in ATX/MPH, 2 patients in ATX/PBO). Sixteen percent discontinued the study due to AE, but no difference between augmentation groups. Atomoxetine treatment was efficacious on outcome measures (P <or= .001), but methylphenidate did not enhance response.

CONCLUSION

Methylphenidate appears to be safely combined with atomoxetine, but conclusions limited by small sample. With atomoxetine treatment, 43% of patients achieved normalization on ADHD ratings.