Long-term safety and tolerability of atomoxetine in Japanese adults with attention deficit hyperactivity disorder

Recommendation for Long-term Management of Adult Attention-Deficit/Hyperactivity Disorder in Military Populations, Veterans, and Dependents: A Narrative Review

INTRODUCTION

In addition to the higher burden of mental health disease in the military, there is a compounding antecedent association between behavioral health comorbidities and the treatment of attention-deficit/hyperactivity disorder (ADHD) in this population. Despite the low prevalence of new-onset ADHD in adults globally, the rate of stimulant (i.e., amphetamines) prescription is increasing. Stimulants can exacerbate mental health disease (often masquerading as ADHD symptomatology), precluding optimal treatment of the underlying etiology and imposing unnecessary dangerous side effects. This study aimed to evaluate the long-term safety and efficacy of stimulants for managing adult ADHD.

METHODS

A nine-member multidisciplinary team reviewed a PubMed search with the terms "adult," "ADHD," and "stimulant." Targeted PubMed and Google Scholar searches for "adult ADHD" paired with Food and Drug Administration -approved ADHD medications and Google Scholar literature using forward and reverse snowballing methods were performed for high-quality studies focusing on long-term treatment in ADHD. An evidence table and clinical algorithm were developed from the review.

RESULTS

Of the 1,039 results, 50 articles were fully reviewed, consisting of 21 descriptive and experimental studies, 18 observational, and 11 systematic reviews and meta-analyses. Illustrative cases within the structured discussion of the results highlighted ADHD and psychiatric comorbidities, risks, harms, and benefits of stimulant use, medication mechanisms of action, and limitations of the current evidence.

DISCUSSION

The dearth of high-quality studies on long-term ADHD management in adults fails to establish a causal relationship between stimulant use and physiological harm. Despite mixed evidence supporting the benefit of stimulants, there is clear evidence regarding the risk of harm. The serious risks of stimulants include arrhythmias, myocardial infarction, stroke/transient ischemic attack, sudden death, psychosis, and worsening of behavioral health disease. Additionally, there is a possible long-term risk of harm due to chronic sympathetic load (i.e., cardiovascular system remodeling). Stimulants pose a greater risk for addiction and abuse compared to other evidence-based nonstimulant medications that have similar effectiveness. Both stimulants and nonstimulants might promote favorable neuroanatomical changes for long-term improvement of ADHD symptoms, but nonstimulants (atomoxetine) have the pharmacological advantage of also mitigating the effects of sympathetic load (sympatholysis) and anxiety (anxiolysis). Given the physiological uncertainty of extended stimulant use for adults, especially older adults with vulnerable cardiovascular systems, clinicians should proceed cautiously when considering initiating or sustaining stimulant therapy. For long-term treatment of ADHD in adults, clinicians should consider nonstimulant alternatives (including behavioral therapy) due to the comparatively lower side effect risk and the possible additional benefit in patients with behavioral health comorbidities.

CONCLUSION

Long-term safety of stimulant use for adults with ADHD is uncertain, as existing studies are limited in quality and duration. This is particularly important for military populations with higher rates of mental health conditions. Managing ADHD and related conditions requires prioritizing cardiovascular safety, especially for older adults. Nonstimulant options can be helpful, especially in comorbid psychiatric disease. Before treating ADHD, ruling out and controlling other behavioral health conditions is essential to avoid masking or worsening underlying issues and reducing unnecessary medication side effects.

Atomoxetine-induced focal seizures with contralateral hypoperfusion and hyper-CKemia

One of the drugs used to treat attention deficit hyperactivity syndrome is atomoxetine. Usually, the drug is well tolerated but in rare cases adverse advents may occur. An 18-year-old female under atomoxetine (60 mg/d) since 2 years for attention deficit hyperactivity syndrome since age 13 years, developed sudden onset headache, hemianopia to the right, hypoesthesia of the tongue and right arm, aphasia, and depersonalisation. Blood tests revealed hyper-CK-emia of 2860U/L, cerebral magnetic resonance imaging showed disturbed perfusion on the left temporo-parieto-occipital region, and electroencephalography (EEG) revealed focal slowing and spikes and sharp waves in the same projections. After discontinuation of atomoxetine, symptoms, EEG, and magnetic resonance imaging findings resolved spontaneously within 48 hours. In conclusion, atomoxetine may rarely cause severe side effects such as complex partial seizures with CK-elevation, transient hypoperfusion of the temporal, parietal and occipital lobes, and prolonged reorientation. Atomoxetine should be discontinued if such side effects occur.

Treatment patterns, health care resource utilization, and costs in Japanese adults with attention-deficit hyperactivity disorder treated with atomoxetine

OBJECTIVE

To describe the characteristics and medication treatment patterns of adult patients with attention-deficit/hyperactivity disorder (ADHD) prescribed atomoxetine in Japan.

MATERIALS AND METHODS

A retrospective analysis of insurance claims data was conducted using the Japan Medical Data Center database. Adults (≥18 years) with ADHD who had ≥1 atomoxetine claim from January 1, 2013 to December 31, 2014, and ≥180 to ≤900 days of follow-up were included. First atomoxetine claim defined the index date. Patient characteristics included age, gender, and comorbid conditions. Treatment patterns assessed included rates of atomoxetine discontinuation, switching, persistence, adherence (assessed via the medication possession ratio), and use of concomitant medications.

RESULTS

A total of 457 adults met all the inclusion criteria. Mean (SD) age was 32.7 (10.4) years, and 61.0% of patients were male. Nearly 72.0% of the patients had at least one comorbid mental health condition in the baseline period; depression (43.8%) and insomnia (40.7%) were the most common mental health comorbidities. Most common physical comorbidities were chronic obstructive pulmonary disease (14.4%) and diabetes (12.9%). Non-ADHD-specific psychotropics were prescribed to 59.7% of patients during the baseline period and to 65.9% during the follow-up period; 6.6% were prescribed non-ADHD-specific psychotropics concomitantly with atomoxetine. Overall, 40.0% of adults discontinued atomoxetine during the entire follow-up period and 65.9% were persistent with atomoxetine therapy at 3 months post-index date. Mean (SD) atomoxetine medication possession ratio was 0.57 (0.25), and 25.4% switched to an alternative ADHD therapy; methylphenidate (22.4%) and non-ADHD-specific psychotropics (77.6%) were the most common medication alternatives. Nearly 8% augmented atomoxetine with methylphenidates, non-stimulants, or non-ADHD-specific psychotropics.

CONCLUSION

In this observational study, a majority of adults with ADHD treated with atomoxetine were still persistent with therapy at 3 months post-index date, with one quarter switching to alternative ADHD therapy. High proportions of mental health comorbidities, along with high use of non-ADHD-specific psychotropic medications in both the baseline and follow-up periods, were observed among patients with ADHD prescribed atomoxetine.

Relationships Between Functional Outcomes and Symptomatic Improvement in Atomoxetine-Treated Adult Patients with Attention-Deficit/Hyperactivity Disorder: Post Hoc Analysis of an Integrated Database

BACKGROUND

Atomoxetine treatment is associated with improvements in functional outcomes in patients with attention-deficit/hyperactivity disorder (ADHD), although relationships between improvements in these outcomes and reductions in ADHD symptoms have not been comprehensively investigated in adults.

OBJECTIVES

The aim of this study was to assess relationships between functional outcomes and ADHD symptoms (primary objective), and to assess time courses of changes in functional outcomes from baseline to weeks 10 and 24 (secondary objective).

METHODS

We analyzed data pooled from seven Eli Lilly-sponsored placebo-controlled trials of atomoxetine in adults with ADHD that had Conners' Adult ADHD Rating Scales-Investigator Rated: Screening Version (CAARS-Inv:SV) total scores and functional outcome data at baseline and at week 10. Two trials also had these data at week 24. Patients were included in these pooled analyses if they had a CAARS-Inv:SV total score at baseline and at one or more post-baseline visits at weeks 10 or 24, or had post-baseline scores that would allow missing scores at weeks 10 or 24 to be imputed. To address the primary objective, changes in functional outcomes during treatment with atomoxetine versus placebo were assessed using last observation carried forward (LOCF) analysis of covariance (ANCOVA) and mixed-effects model repeated measures (MMRM) analysis, and correlations between score changes in CAARS-Inv:SV total and functional outcomes were assessed using Spearman's rank correlation coefficient (r) at weeks 10 and 24. The secondary objective was addressed using MMRM.

RESULTS

At baseline, patients generally had moderately severe or worse ADHD symptoms (based on CAARS-Inv:SV total scores) and impaired functional outcomes (based on Adult ADHD Quality-of-Life [AAQoL], Behavior Rating Inventory of Executive Function-Adult Version [BRIEF-A], Sheehan Disability Scale [SDS], and 36-item Short-Form Health Survey [SF-36] scores). These baseline characteristics were comparable in the atomoxetine and placebo groups. For atomoxetine versus placebo, statistically significant improvements were detected in AAQoL total and subscores at weeks 10 and 24, and in BRIEF-A Self-Report scores at week 10, but not in BRIEF-A Informant Report or SDS scores at week 10 (no BRIEF-A or SDS data were available at week 24), and not in SF-36 at weeks 10 or 24. All functional improvements were gradual. During treatment with atomoxetine, there were moderate correlations between reductions in CAARS-Inv:SV total scores and increases in AAQoL total and subscores at weeks 10 and 24 (r range -0.58 to -0.39; n = 394-545), and also with reductions in BRIEF-A Self-Report at week 10 (r = 0.49; n = 256). With placebo, moderate correlations were also found between reductions in CAARS-Inv:SV total scores and increases in AAQoL total and subscores at weeks 10 and 24 (r range -0.56 to -0.28; n = 321-542), and with reductions in BRIEF-A Self-Report at week 10 (r = 0.49; n = 271). However, correlations between changes in CAARS-Inv:SV and BRIEF-A Informant at week 10 were low for atomoxetine-treated patients (r = 0.25; n = 65), moderate with placebo (r = 0.42; n = 72), and there were low/no correlations between changes in CAARS-Inv:SV and functional outcome rating scales that are not specific to ADHD; that is, for atomoxetine-treated patients, SDS total r = 0.19 (n = 32 at week 10) and SF-36 r range - 0.20 to -0.01 (n = 51 at week 10, n = 183 at week 24).

CONCLUSIONS

Atomoxetine-treated adult patients experienced improvements in functional outcomes (AAQoL and BRIEF-A Self-Report) that correlated with reductions in ADHD symptoms. Although atomoxetine improved both the ADHD symptoms and functional outcomes, the correlation between symptoms and functional outcomes was low to moderate, suggesting that they measure overlapping but different aspects of the disorder. Hence, clinicians should assess not just ADHD symptoms, but also the functional impairments.

Post Hoc Analysis of Potential Predictors of Response to Atomoxetine for the Treatment of Adults with Attention-Deficit/Hyperactivity Disorder using an Integrated Database

BACKGROUND

Responses to atomoxetine vary for individual patients with attention-deficit/hyperactivity disorder (ADHD). However, we do not know whether any factors can be used to reliably predict how individuals with ADHD will respond to treatment.

OBJECTIVE

Our objective was to evaluate background variables that facilitate early identification of those adults with ADHD who are likely to respond to treatment with atomoxetine.

METHODS

We pooled data for atomoxetine-treated adults with ADHD from 12 clinical trials for a short-term (10-week) analysis, and from 11 clinical trials for a long-term (24-week) analysis. Patients not meeting a response definition [≥30 % reduction in Conners' Adult ADHD Rating Scales-Investigator Rated: Screening Version (CAARS-Inv:SV) total score and Clinical Global Impressions of ADHD Severity Scale (CGI-S) score ≤3 at endpoint], or who discontinued, were defined as non-responders. Another definition of response (≥30 % reduction in CAARS-Inv:SV total score at endpoint) was also used in these analyses; only the results with the former definition are shown in this abstract, as the same conclusions were gained with both definitions. A treatment-specified subgroup detection tool (a resampling-based ensemble tree method) was used to identify predictors of response.

RESULTS

Of 1945 adults in the long-term analysis, 548 (28.2 %) were responders to atomoxetine at week 24; 65.2 % of 1397 non-responders had discontinued. Of 4524 adults in the short-term analysis, 1490 (32.9 %) were responders at week 10; 33.2 % of 1006 non-responders had discontinued. No analyzed baseline parameters (age, sex, prior stimulant use, ADHD subtype, CAARS-Inv:SV, CGI-S) were statistically significant predictors of response. Reductions in CAARS-Inv:SV total, CAARS-Inv:SV subscores, and CGI-S at week 4 in the short-term analysis, and at weeks 4 or 10 in the long-term analysis, were statistically significant predictors of response, i.e., patients with versus without these reductions early in treatment were more likely to be clinical responders at later time points. Sensitivity ranged from 28.6 to 85.9 %, and specificity ranged from 23.8 to 86.7 %. Predictors with higher sensitivity had lower specificity, and vice versa.

CONCLUSIONS

Reductions in CAARS-Inv:SV and CGI-S scores at weeks 4 and 10 are statistically significant predictors of response to atomoxetine at later time points in adults with ADHD. However, the predictors identified by these analyses are not reliable enough for use in clinical practice. The only currently available method to judge whether individuals with ADHD will respond to atomoxetine is to start treatment and assess the response over an extended period, sometimes longer than 10 weeks.

Atomoxetine Increased Effect over Time in Adults with Attention-Deficit/Hyperactivity Disorder Treated for up to 6 Months: Pooled Analysis of Two Double-Blind, Placebo-Controlled, Randomized Trials

Introduction

Changes in the magnitude of efficacy throughout 26 weeks of atomoxetine treatment, along with impact of dosing, were evaluated in adults with ADHD from two randomized, double‐blind, placebo‐controlled studies.

Aims

Pooled placebo (n = 485) and atomoxetine (n = 518) patients, dosed 25, 40, 60, 80 (target dose), or 100 mg daily, were assessed. Change from baseline in Conners’ Adult ADHD Rating Scale–Investigator Rated Scale: Screening Version (CAARS) total ADHD symptoms score and Adult ADHD Investigator Symptom Rating Scale (AISRS) total score were analyzed using mixed‐model repeated measures, with least squares mean change, effect size, and response rate calculated at 1, 2, 4, 8, 12, 16, 22, and 26 weeks.

Results

Decreases on CAARS for atomoxetine‐ versus placebo‐treated patients were consistently statistically significantly greater at every time point beginning at one week (P ≤ 0.006, 0.28 effect size). By 4 weeks, comparison was −13.19 compared with −8.84 (P < 0.0001, 0.45 effect size). By 26 weeks, mean change was −15.42 versus −9.71 (0.52 effect size); increase in effect size over time was most pronounced in the 80 mg group (0.82 effect size). AISRS demonstrated similar results. Atomoxetine response rate (CAARS 50% decrease) continued to increase throughout 26 weeks.

Conclusions

Atomoxetine treatment in adults with ADHD was associated with small effect sizes after 4 weeks and moderate effect sizes by 6 months of treatment. The data support increased effect size and response rate over time during longer‐term treatment at target dose.

Atomoxetine in patients with ADHD: A clinical and pharmacological review of the onset, trajectory, duration of response and implications for patients

This article reviews data providing new insight into the trajectory of response and maintenance of response of atomoxetine in the treatment of child and adult attention-deficit hyperactivity disorder (ADHD). This nonsystematic review includes: onset of action and duration of effect, response rate, effect size, time to optimal response and norepinephrine transporter blockade biomarker data. Atomoxetine can have an onset of action within 1-2 weeks of starting treatment, but there is an incrementally increasing response for up to 24 weeks or longer. Responder rates and effect sizes are similar to methylphenidate. Upon treatment discontinuation, relapse rates are lower than expected. In adults, 50% maintain their response for at least 6 months after stopping atomoxetine, following 6 months of treatment. Single-dose atomoxetine can provide 24-hour efficacy, despite a 5-hour plasma half-life. Hypotheses can be generated relating to neuroadaptive changes, to explain these findings. Atomoxetine has a trajectory of response that is incremental over a long period of time, with a greater than expected maintenance of response. This has implications for physician atomoxetine dosing and efficacy assessment, patient education and outcomes, and for clinical trial design and assessment of comparative efficacy with stimulant medications.

Atomoxetine treatment in adults with attention-deficit/hyperactivity disorder

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a CNS disorder that has its onset in childhood, but often persists into adulthood. There is growing recognition that adult ADHD can result in multiple negative consequences for individuals. ADHD is also often associated with a number of comorbid psychiatric disorders. Atomoxetine (ATX), a nonstimulant, selective noradrenergic reuptake inhibitor, was approved in the United States in 2002 for the treatment of ADHD in children and adolescents, as well as adults. We review here the safety and efficacy of ATX in adults with ADHD, including data in special populations, functional outcomes, as well as provider and patient real-world perceptions.

METHODS

We searched the databases Embase, MEDLINE and PsycINFO using the terms 'ADHD' and 'adult' and 'ATX' capturing publications from January 1, 1998, to March 27, 2014. Only publications in English were considered.

RESULTS

ATX demonstrated significantly greater improvement than placebo (PBO) on the Conners Adult ADHD Rating Scale-Investigator rated:Screening Version (CAARS-Inv:SV) in all trials (N = 6; total score difference ranged from -3.5 to -5.5). For long-term trials using the CAARS-Inv:SV, ATX demonstrated significantly greater improvement than PBO in three of four trials (total score differences ranged from -0.1 to -6.0). In short-term studies, ATX showed significantly greater improvement than PBO on the Adult ADHD Quality-of-Life scale total score in three of three studies, but results were mixed on the Sheehan Disability Scale. Three studies of ATX have reported statistically significant improvement (compared with PBO) on the Behavior Rating Inventory of Executive Function-Adult Version Self Report scale. The most common adverse events (occurring in ≥ 10% of patients taking ATX) were nausea, dry mouth, decreased appetite, insomnia and fatigue.

CONCLUSIONS

ATX is an important treatment option for the right patient. ATX can provide long-term, consistent symptom relief and functional improvement for adults with ADHD.

Patterns of long-term and short-term responses in adult patients with attention-deficit/hyperactivity disorder in a completer cohort of 12 weeks or more with atomoxetine

BACKGROUND

Atomoxetine is a well-established pharmacotherapy for adult ADHD. Long-term studies show incremental reductions in symptoms over time. However, clinical experience suggests that patients differ in their response patterns.

METHODS

From 13 Eli Lilly-sponsored studies, we pooled and analyzed data for adults with ADHD who completed atomoxetine treatment at long-term (24 weeks; n=1443) and/or short-term (12 weeks; n=2830) time-points, and had CAARS-Inv:SV total and CGI-S data up to or after these time-points and at Week 0 (i.e. at baseline, when patients first received atomoxetine). The goal was to identify and describe distinct trajectories of response to atomoxetine using hierarchical clustering methods and linear mixed modelling.

RESULTS

Based on the homogeneity of changes in CAARS-Inv:SV total scores, 5 response clusters were identified for patients who completed long-term (24 weeks) treatment with atomoxetine, and 4 clusters were identified for patients who completed short-term (12 weeks) treatment. Four of the 5 long-term clusters (comprising 95% of completer patients) showed positive trajectories: 2 faster responding clusters (L1 and L2), and 2 more gradually responding clusters (L3 and L4). Responses (i.e.≥30% reduction in CAARS-Inv:SV total score, and CGI-S score≤3) were observed at 8 and 24 weeks in 80% and 95% of completers in Cluster L1, versus 5% and 48% in Cluster L4.

CONCLUSIONS

While many adults with ADHD responded relatively rapidly to atomoxetine, others responded more gradually without a clear plateau at 24 weeks. Longer-term treatment may be associated with greater numbers of responders.

Safety and tolerability of edivoxetine as adjunctive treatment to selective serotonin reuptake inhibitor antidepressants for patients with major depressive disorder

Objective:

The aim of this analysis was to assess the safety profile of edivoxetine as adjunctive treatment to selective serotonin reuptake inhibitor (SSRI) antidepressants.

Methods:

A pooled analysis was conducted on data obtained from the integrated safety database of edivoxetine as adjunctive treatment to SSRIs. Safety and tolerability assessments included discontinuation rates, spontaneously reported treatment-emergent adverse events (TEAEs), clinical laboratory tests, blood pressure (BP) and pulse, and electrocardiograms (ECGs).

Results:

The analysis included 1260 patients treated with adjunctive edivoxetine and 806 treated with adjunctive placebo. Study completion rates were 85.2% and 84.5% (p=0.994), respectively. Discontinuations due to adverse events were 4.9% and 3.5% (p=0.07), respectively. Significantly more patients in the adjunctive edivoxetine group compared with adjunctive placebo group reported at least one TEAE (56.8 vs 43.7%, p<0.001). The most common TEAEs (occurred ≥5% frequency) were hyperhidrosis, nausea, and tachycardia. Mean changes in sitting BP and pulse at the last visit were increased significantly in patients treated with adjunctive edivoxetine compared with adjunctive placebo (SBP: 2.7 vs 0.5 mm Hg, p<0.001; DBP: 4.1 vs 0.8 mm Hg, p<0.001; pulse: 8.8 vs −1.3 bpm, p<0.001). There were no clinically significant changes in laboratory measures.

Conclusions:

The tolerability and safety profile of edivoxetine as adjunctive treatment to SSRI antidepressants was consistent with its norepinephrine reuptake inhibitor mechanism of action, and was comparable with edivoxetine monotherapy treatment in patients with major depressive disorder.