Severe liver injury after initiating therapy with atomoxetine in two children

Comparison of serious adverse effects of methylphenidate, atomoxetine and amphetamine in the treatment of ADHD: an adverse event analysis based on the FAERS database

BACKGROUND

Methylphenidate, atomoxetine, and amphetamine are the most commonly prescribed medications for ADHD, approved by the FDA. Despite their widespread use, real-world studies on their serious adverse effects are limited. This study leverages the FAERS database to analyze the safety of these drugs.

METHODS

A retrospective analysis was conducted using FAERS data from 2004 to 2023. Adverse event (AE) signals for methylphenidate, atomoxetine, and amphetamine were identified by calculating reporting odds ratios (RORs), proportional reporting ratios (PRRs), information components (ICs), and empirical Bayesian geometric mean (EBGM).

RESULTS

The analysis included 72,298 reports, with 37,471 linked to methylphenidate, 17,335 to atomoxetine, and 17,492 to amphetamine. Significant AE signals were found, especially in psychotic disorders for methylphenidate (ROR = 4.47, PRR = 3.7) and amphetamines (ROR = 4.06, PRR = 3.43), and psychiatric and reproductive disorders for atomoxetine (ROR = 5.44, PRR = 4.29; ROR = 2.49, PRR = 2.46). At the PT level, the most common adverse safety signals for the three ADHD drugs were Application site erythema, Somnolence, and Headache. Further analysis showed that "Aggression", "Mydriasis", "Trichotillomania" and suicide-related adverse reactions showed strong signals in the three ADHD drugs. However, there are also differences between the three ADHD medications. For example, serious adverse effects related to cardiovascular and neurological effects were stronger in amphetamines, with the "coronary artery dissection" and "carotid artery dissection" signals being the most significant; "Precocious puberty" has a stronger signal in methylphenidate, and the signal associated with elevated liver enzymes is strongest in atomoxetine. In addition, we also found some PTs that were not included in the drug label, such as "Disturbance in social behaviour" and "Trichotillomania".

CONCLUSIONS

In this study, pharmacovigilance analysis of methylphenidate, atomoxetine, and amphetamine was performed using the FAERS database, and we identified significant safety signals. Of note, three ADHD medications are associated with suicide-related signals, amphetamine associated with coronary artery dissection, methylphenidate associated with precocious puberty, and atomoxetine associated with testicle, penile lesions, and liver damage, which require special attention. This study provides a reference for the clinical personalized medication of ADHD patients.

Viloxazine for the Treatment of Attention Deficit Hyperactivity Disorder

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Bioactivation and Reactivity Research Advances - 2021 year in review

This year's review on bioactivation and reactivity began as a part of the annual review on biotransformation and bioactivation led by Cyrus Khojasteh (Khojasteh et al., 2021, 2020, 2019, 2018, 2017; Baillie et al., 2016). Increased contributions from experts in the field led to the development of a stand alone edition for the first time this year focused specifically on bioactivation and reactivity. Our objective for this review is to highlight and share articles which we deem influential and significant regarding the development of covalent inhibitors, mechanisms of reactive metabolite formation, enzyme inactivation, and drug safety. Based on the selected articles, we created two sections: (1) reactivity and enzyme inactivation, and (2) bioactivation mechanisms and safety (Table 1). Several biotransformation experts have contributed to this effort from academic and industry settings.

Metabolic Activation of Atomoxetine Mediated by Cytochrome P450 2D6

Atomoxetine (ATX) is a neurological drug widely used for the treatment of attention deficit-hyperactivity disorder. Liver injury has been documented in patients administered ATX. The mechanism of ATX's toxic action is less clear. This study is aimed to characterize reactive metabolites of ATX in vitro and in vivo to assist our understanding of the mechanisms of ATX hepatotoxicity. A hydroxylated metabolite, along with an O-dealkylation metabolite, was found in ATX-supplemented rat liver microsome incubations. Additionally, two glutathione (GSH) conjugates and two N-acetylcysteine (NAC) conjugates were observed in rat liver microsome incubations containing ATX, NADPH, and GSH or NAC. The corresponding GSH conjugates and NAC conjugates were found in bile and urine of ATX-treated rats, respectively. Recombinant P450 enzyme incubation study demonstrated that CYP2D6 dominated the metabolic activation of ATX. The insights gained from this study may be of assistance to illuminate the mechanisms of ATX-induced hepatotoxicity.

Retrospective analysis of adverse events associated with non-stimulant ADHD medications reported to the united states food and drug administration

Attention deficit hyperactivity disorder (ADHD) is one of the most common neurobehavioral disorders in children and although stimulant medications remain first line to treat the disorder, some families prefer nonstimulants. The goal is to analyze the adverse events (AE) associated with nonstimulant medications using post-marketing drug surveillance data. We aim to increase awareness and aide patient education. A retrospective study of adverse drug events with atomoxetine, clonidine, and guanfacine was performed using the Federal Drug Administration Adverse Event Reporting System (FAERS) Database. Results show that the most commonly reported AEs, as defined by FAERS, were ineffectiveness (9.91-14.15%) fatigue (8.93%), and somnolence (8.8-10.16%). Of those taking atomoxetine, suicidal and self-injurious ideation was reported to a similar degree amongst all age groups. Suicidal ideation was listed within the top 20 most reported AEs for all three medications. It is more likely that some patients will experience milder side effects. We suggest providing these data to patients to help overcome the stigma of starting medication, especially if they prefer nonstimulants. Serious AEs are still reported to a small degree, thus monitoring and consistent patient education remains important. We also recommend educating a wider demographic of patients about recognizing potential development of suicidal thoughts.

Once-Daily SPN-812 200 and 400 mg in the treatment of ADHD in School-aged Children: A Phase III Randomized, Controlled Trial

PURPOSE

SPN-812 (viloxazine extended-release) is under investigation for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents. This Phase III study evaluated the efficacy and tolerability of SPN-812 200 and 400 mg once daily in children 6-11 years of age with ADHD.

METHODS

Patients were randomly assigned to receive SPN-812 200 mg, SPN-812 400 mg, or placebo, once daily for 8 weeks (including ≤3 weeks titration period). The primary efficacy endpoint was the change from baseline (CFB) in ADHD Rating Scale (RS)-5 Total score at end of study (EOS). Key secondary endpoints included Clinical Global Impression-Improvement (CGI-I) score at EOS, CFB in Conners 3-Parent Short Form (PS) composite T-score at EOS, and CFB in Weiss Functional Impairment Rating Scale-Parent (WFIRS-P) Total average score at EOS.

FINDINGS

A total of 313 patients were enrolled, with 301 in the intent-to-treat population (194 boys, 107 girls; mean age [SD], 8.4 [1.7] years). At EOS, the CFBs in ADHD-RS-5 Total score and CGI-I score were significantly improved with both 200- and 400-mg/d SPN-812 versus placebo (ADHD-RS-5, P = 0.0038 and 0.0063, respectively; CGI-I, P = 0.0028 and 0.0099). At EOS, the CFB in Conners 3-PS composite T-score was significantly improved with 200- (P = 0.0064), but not 400-mg/d (P = 0.0917), SPN-812 compared to placebo. No significant difference between the groups was found in WFIRS-P Total average score. The rate of discontinuations due to adverse events in both SPN-812 treatment groups combined was <5%.

IMPLICATIONS

SPN-812 200 and 400 mg once daily was associated with improvements in ADHD symptoms in school-aged children and was generally well tolerated. ClinicalTrials.gov identifier: NCT03247543.

The Mechanism, Clinical Efficacy, Safety, and Dosage Regimen of Atomoxetine for ADHD Therapy in Children: A Narrative Review

Atomoxetine, a selective norepinephrine (NE) reuptake inhibitor, was approved for attention deficit/hyperactivity disorder (ADHD) treatment in children, adolescents and adults. We searched the database PubMed/MEDLINE (2000 to October 1, 2021). Only publications in English were considered. Atomoxetine inhibits the presynaptic norepinephrine transporter (NET), preventing the reuptake of NE throughout the brain along with inhibiting the reuptake of dopamine in specific brain regions such as the prefrontal cortex (PFC). The novel mechanism of atomoxetine also includes several new brain imaging studies and animal model studies. It is mainly metabolized by the highly polymorphic drug metabolizing enzyme cytochrome P450 2D6 (CYP2D6). Atomoxetine is effective and generally well tolerated. ADHD is often accompanied by multiple comorbidities. A series of studies have been published suggesting that atomoxetine is effective in the treatment of ADHD symptoms for children with various types of comorbidity. In some cases, it is possible that atomoxetine may have a positive influence on the symptoms of comorbidities. Atomoxetine can be administered either as a single daily dose or split into two evenly divided doses, and has a negligible risk of abuse or misuse. The latest guideline updated that clinical dose selection of atomoxetine was recommended based on both CYP2D6 genotype and the peak concentration. To have a more comprehensive understanding of atomoxetine, this review sets the focus on the mechanism, clinical efficacy and dosage regimen in detail, and also touches on those studies regarding adverse reactions of atomoxetine.

Metabolic profiling of norepinephrine reuptake inhibitor atomoxetine

Atomoxetine (ATX), a selective and potent inhibitor of the presynaptic norepinephrine transporter, is used mainly to treat attention-deficit hyperactivity disorder. Although multiple adverse effects associated with ATX have been reported including severe liver injuries, the mechanisms of ATX-related toxicity remain largely unknown. Metabolism frequently contributes to adverse effects of a drug through reactive metabolites, and the bioactivation status of ATX is still not investigated yet. Here, we systematically investigated ATX metabolism, bioactivation, species difference in human, mouse, and rat liver microsomes (HLM, MLM, and RLM) and in mice using metabolomic approaches as mice and rats are commonly used animal models for the studies of drug toxicity. We identified thirty one ATX metabolites and adducts in LMs and mice, 16 of which are novel. In LMs, we uncovered two methoxyamine-trapped aldehydes, two cyclization metabolites, detoluene-ATX, and ATX-N-hydroxylation for the first time. Detoluene-ATX and one cyclization metabolite were also observed in mice. Using chemical inhibitors and recombinant CYP enzymes, we demonstrated that CYP2C8 and CYP2B6 mainly contribute to the formation of aldehyde; CYP2D6 is the dominant enzyme for the formation of ATX cyclization and detoluene-ATX; CYP3A4 is major enzyme responsible for the hydroxylamine formation. The findings concerning aldehydes should be very useful to further elucidate the mechanistic aspects of adverse effects associated with ATX from metabolic angles. Additionally, the species differences for each metabolite should be helpful to investigate the contribution of specific metabolites to ATX toxicity and possible drug-drug interactions in suitable models.

Cognitive-behavioural interventions for attention deficit hyperactivity disorder (ADHD) in adults

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a developmental condition characterised by symptoms of inattention, hyperactivity and impulsivity, along with deficits in executive function, emotional regulation and motivation. The persistence of ADHD in adulthood is a serious clinical problem.ADHD significantly affects social interactions, study and employment performance.Previous studies suggest that cognitive-behavioural therapy (CBT) could be effective in treating adults with ADHD, especially when combined with pharmacological treatment. CBT aims to change the thoughts and behaviours that reinforce harmful effects of the disorder by teaching people techniques to control the core symptoms. CBT also aims to help people cope with emotions, such as anxiety and depression, and to improve self-esteem.

OBJECTIVES

To assess the effects of cognitive-behavioural-based therapy for ADHD in adults.

SEARCH METHODS

In June 2017, we searched CENTRAL, MEDLINE, Embase, seven other databases and three trials registries. We also checked reference lists, handsearched congress abstracts, and contacted experts and researchers in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating any form of CBT for adults with ADHD, either as a monotherapy or in conjunction with another treatment, versus one of the following: unspecific control conditions (comprising supportive psychotherapies, no treatment or waiting list) or other specific interventions.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures suggested by Cochrane.

MAIN RESULTS

We included 14 RCTs (700 participants), 13 of which were conducted in the northern hemisphere and 1 in Australia.Primary outcomes: ADHD symptomsCBT versus unspecific control conditions (supportive psychotherapies, waiting list or no treatment)- CBT versus supportive psychotherapies: CBT was more effective than supportive therapy for improving clinician-reported ADHD symptoms (1 study, 81 participants; low-quality evidence) but not for self-reported ADHD symptoms (SMD -0.16, 95% CI -0.52 to 0.19; 2 studies, 122 participants; low-quality evidence; small effect size).- CBT versus waiting list: CBT led to a larger benefit in clinician-reported ADHD symptoms (SMD -1.22, 95% CI -2.03 to -0.41; 2 studies, 126 participants; very low-quality evidence; large effect size). We also found significant differences in favour of CBT for self-reported ADHD symptoms (SMD -0.84, 95% CI -1.18 to -0.50; 5 studies, 251 participants; moderate-quality evidence; large effect size).CBT plus pharmacotherapy versus pharmacotherapy alone: CBT with pharmacotherapy was more effective than pharmacotherapy alone for clinician-reported core symptoms (SMD -0.80, 95% CI -1.31 to -0.30; 2 studies, 65 participants; very low-quality evidence; large effect size), self-reported core symptoms (MD -7.42 points, 95% CI -11.63 points to -3.22 points; 2 studies, 66 participants low-quality evidence) and self-reported inattention (1 study, 35 participants).CBT versus other interventions that included therapeutic ingredients specifically targeted to ADHD: we found a significant difference in favour of CBT for clinician-reported ADHD symptoms (SMD -0.58, 95% CI -0.98 to -0.17; 2 studies, 97 participants; low-quality evidence; moderate effect size) and for self-reported ADHD symptom severity (SMD -0.44, 95% CI -0.88 to -0.01; 4 studies, 156 participants; low-quality evidence; small effect size).Secondary outcomesCBT versus unspecific control conditions: we found differences in favour of CBT compared with waiting-list control for self-reported depression (SMD -0.36, 95% CI -0.60 to -0.11; 5 studies, 258 participants; small effect size) and for self-reported anxiety (SMD -0.45, 95% CI -0.71 to -0.19; 4 studies, 239 participants; small effect size). We also observed differences in favour of CBT for self-reported state anger (1 study, 43 participants) and self-reported self-esteem (1 study 43 participants) compared to waiting list. We found no differences between CBT and supportive therapy (1 study, 81 participants) for self-rated depression, clinician-rated anxiety or self-rated self-esteem. Additionally, there were no differences between CBT and the waiting list for self-reported trait anger (1 study, 43 participants) or self-reported quality of life (SMD 0.21, 95% CI -0.29 to 0.71; 2 studies, 64 participants; small effect size).CBT plus pharmacotherapy versus pharmacotherapy alone: we found differences in favour of CBT plus pharmacotherapy for the Clinical Global Impression score (MD -0.75 points, 95% CI -1.21 points to -0.30 points; 2 studies, 65 participants), self-reported depression (MD -6.09 points, 95% CI -9.55 points to -2.63 points; 2 studies, 66 participants) and self-reported anxiety (SMD -0.58, 95% CI -1.08 to -0.08; 2 studies, 66 participants; moderate effect size). We also observed differences favouring CBT plus pharmacotherapy (1 study, 31 participants) for clinician-reported depression and clinician-reported anxiety.CBT versus other specific interventions: we found no differences for any of the secondary outcomes, such as self-reported depression and anxiety, and findings on self-reported quality of life varied across different studies.

AUTHORS' CONCLUSIONS

There is low-quality evidence that cognitive-behavioural-based treatments may be beneficial for treating adults with ADHD in the short term. Reductions in core symptoms of ADHD were fairly consistent across the different comparisons: in CBT plus pharmacotherapy versus pharmacotherapy alone and in CBT versus waiting list. There is low-quality evidence that CBT may also improve common secondary disturbances in adults with ADHD, such as depression and anxiety. However, the paucity of long-term follow-up data, the heterogeneous nature of the measured outcomes, and the limited geographical location (northern hemisphere and Australia) limit the generalisability of the results. None of the included studies reported severe adverse events, but five participants receiving different modalities of CBT described some type of adverse event, such as distress and anxiety.

Analysis of Immunogenetic Factors in Idiosyncratic Drug-induced Liver Injury in the Pediatric Population

OBJECTIVES

Idiosyncratic drug-induced liver injury is a multifactorial complex disease, in which the toxic potential of the drug, together with genetic and acquired factors and deficiencies in adaptive processes, which limit the extent of damage, can determine susceptibility, and make individuals unique in their development of hepatotoxicity. The aim of the present study is to analyse the genetic factors (human leukocyte antigen [HLA], cytokine polymorphisms, and killer cell immunoglobulin-like receptor [KIR] genotype) of children who experience an episode of drug-induced liver injury.

PATIENTS AND METHODS

Prospective multicentre case-control study. The subjects included in the study were 30 paediatric patients-infants and children ages between 0 and 15 years and who presented possible liver disease associated with the intake of medicines, herbal products, drugs, or toxins. As a control group, 62 subjects were selected.

RESULTS

Although HLAC0401 and HLADQB0603 may provide a hepatoprotective mechanism in the paediatric population, HLADQA0102 and HLA-DR12 are more commonly found in sick children and their presence may be related to liver damage. The KIR inhibitor KIR3DL1 was not present in any child in the control group.

CONCLUSIONS

Polymorphisms that are low producers of interleukin-10 occur more frequently in children who have experienced hepatotoxicity.

A Systematic Review of the Use of Bupropion for Attention-Deficit/Hyperactivity Disorder in Children and Adolescents

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent neuropsychiatric disorders of childhood and adolescence. Stimulants are usually the first choice of drug; however, as many as 20% of patients do not respond to them. Stimulants may also worsen comorbid sleep, mood, and anxiety disorders, and they are associated with problems of misuse and diversion. Bupropion, a dopamine and norepinephrine reuptake inhibitor, is a promising nonstimulant alternative with reports of positive outcomes for ADHD management in both adolescent and adult populations. This study systematically reviews clinical trials on the subject.

METHODS

Using the keywords bupropion or Wellbutrin or Zyban or Elontril and attention deficit hyperactivity disorder or ADHD or ADDH, a preliminary search on the PubMed and Ovid databases yielded 25,455 articles published in English between January 1, 1988 and May 1, 2016. Of these, there were only six articles on clinical trials involving children. Full articles were also reviewed for references of interest.

RESULTS

All available open, controlled, and randomized trials demonstrated bupropion's efficacy in improving ADHD symptoms. The three head-to-head trials found that bupropion had efficacy comparable to methylphenidate (p > 0.05). However, a large double-blind, placebo-controlled multicenter study of bupropion found smaller effect sizes for bupropion, as quantified using teacher and parent ratings of ADHD symptoms, than methylphenidate. In terms of tolerability, a head-to-head trial found that headache was observed more frequently in the methylphenidate-treated group than in the bupropion-treated group, whereas the frequency of other side effects did not differ significantly.

CONCLUSION

Current findings should be interpreted with caution because of the very limited database. Bupropion should be considered for pharmacological management of childhood and adolescent ADHD, but more randomized controlled trials with larger sample sizes are warranted. There is also some evidence of its benefits in children with comorbid ADHD and conduct, substance use, or depressive disorders.

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.

ADHD & Pharmacotherapy: Past, Present and Future: A Review of the Changing Landscape of Drug Therapy for Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is the most common neurobiological disorder in children, with a prevalence of ~6-7%^1,2 that has remained stable for decades². The social and economic burden associated with patients³, families, and broader systems (healthcare/educational) is substantial, with the annual economic impact of ADHD exceed $30 billion in the US alone⁴. Efficacy of pharmacotherapy in treating ADHD symptoms has generally been considerable with at least ¾ of individuals benefitting from pharmacotherapy, typically in the form of stimulants⁵. In this review, we begin by briefly reviewing the history of pharmacotherapy in relation to ADHD, before focusing (primarily) on the state-of-the-field on themes such as biophysiology, pharmacokinetics, and pharmacogenomics. We conclude with a summary of emerging clinical and research studies, particularly the potential role for precision therapy in matching ADHD patients and drug types.

Attention-Deficit/Hyperactivity Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a neurobiological condition of childhood onset with the hallmarks of inattention, impulsivity, and hyperactivity. Inattention includes excessive daydreaming, disorganization, and being easily distracted. Impulsivity manifests as taking an action before fully thinking of the consequences. Hyperactivity includes an excessive rate of speech and motor activity. Complications of ADHD include academic failure, low self-esteem, poor work performance, substance abuse, criminal justice issues, and social problems. ADHD is predominately due to decreased activity in the frontal lobe. Dopamine and norepinephrine are the main neurotransmitters involved in the pathophysiology of ADHD. Pharmacological treatment of ADHD includes psychostimulants, norepinephrine reuptake inhibitors, α2 agonists, bupropion, and monoamine oxidase inhibitors. The most effective medications are the psychostimulants. Nonpharmacological treatment of ADHD includes coaching, providing structure, academic accommodations, and work accommodations.

Efficacy and Safety of Atomoxetine in the Treatment of Children and Adolescents with Attention Deficit Hyperactivity Disorder

Several non-stimulant medications have been used in the treatment of attention deficit hyperactivity disorder (ADHD). Atomoxetine, was introduced in 2002. The safety and efficacy of atomoxetine in the treatment of ADHD for children, adolescents, and adults has been evaluated in over 4000 patients in randomized controlled studies and double blinded studies as well as in recent large longitudinal studies. This paper provides an updated summary of the literature on atomoxetine, particularly in relation to findings on the short- and long-term safety of atomoxetine in children and adolescents arising from recent large longitudinal cohort studies. Information is presented about the efficacy, safety, and tolerability of this medication.

Characteristics of idiosyncratic drug-induced liver injury in children: results from the DILIN prospective study

BACKGROUND

The spectrum and severity of idiosyncratic drug-induced liver injury (DILI) in children are not well established.

PATIENTS AND METHODS

The DILIN (Drug-Induced Liver Injury Network) Prospective Study is a longitudinal multicenter study designed to determine the etiologies, risk factors, and outcomes of suspected DILI. Between September 2004 and September 2009, 30 children ages 2 to 18 years with suspected DILI who met eligibility criteria were enrolled and studied for at least 6 months.

RESULTS

Mean age was 14 years; 70% were girls. Antimicrobial (50%) and central nervous system agents (40%) were the most commonly implicated drug classes, with minocycline (4), isoniazid (3), azithromycin (3), atomoxetine (3), and lamotrigine (3) the leading agents. Median time from drug initiation to symptom onset was 32 days. Peak (median) liver chemistries were aspartate aminotransferase 503  U/L, alanine aminotransferase 727  U/L, alkaline phosphatase 331  U/L, and total bilirubin 3.9  mg/dL. Autoantibodies were common (64%). Liver injury pattern was hepatocellular 78%, cholestatic 13%, and mixed 9%. The DILI episode was scored: mild 32%, moderate 44%, severe 20%, and fatal (within 6 months) 4%. Causality assessment was definite 36%, very likely 36%, probable 16%, possible 8%, and unlikely 4%. Seven percent had persistent liver test abnormalities at 6-month follow-up suggesting chronic DILI. Liver biopsies from 12 children most frequently demonstrated chronic hepatitis or bile duct injury.

CONCLUSIONS

Idiosyncratic DILI in children is most commonly caused by antimicrobial or central nervous system agents and usually presents with a hepatocellular injury pattern. The majority of patients recover, but morbidity and infrequent mortality are seen.

Idiosyncratic drug-induced liver injury: a clinical update

Drug-induced liver injury (DILI) is a rare but potentially devastating adverse drug reaction. Its presentation can range from asymptomatic elevation in liver biochemistries to fulminant liver failure. Over the past decade, clinical and research interest in the field of idiosyncratic DILI has been intense, and several new findings have been reported. In this article, we provide an update on implicated agents, clinical features, outcomes, and the results of recently reported genetic studies.

Differential Diagnosis and Treatment of Obsessive-Compulsive, Inattentive, and Sleep Symptoms in a 7-Year-Old With PDD-NOS

The overlap in symptoms among autism spectrum disorders (ASDs), anxiety disorders, and attention-deficit/hyperactivity disorder (ADHD) in youth can present diagnostic challenges for clinicians and researchers. Accurate diagnosis and comprehensive treatment can be facilitated by ongoing assessment and close collaboration among members of a multidisciplinary team. Specific treatment guidelines for reducing anxiety and/or inattentive behaviors in children with a primary ASD diagnosis are currently lacking. This case provides an example of how an empirically supported treatment for anxiety, exposure with response prevention (E/RP), in conjunction with pharmacotherapy, can be effective in reducing anxiety and ritualistic/compulsive behaviors in ASDs. This case also exemplifies how attention to and treatment of sleep problems can improve inattentive symptoms and overall functioning.

Tolerability of atomoxetine for treatment of pediatric attention-deficit/hyperactivity disorder in the context of epilepsy

To examine atomoxetine's tolerability in patients with epilepsy, we reviewed medical records of all patients with epilepsy who were treated with atomoxetine in a tertiary care pediatric psychopharmacology practice. Twenty-seven patients (10.1 ± 4.2 years, 63% male) with an average seizure frequency at baseline of 7 ± 24 per month (median: 0, range: 0-90) were found. Symptoms of attention-deficit/hyperactivity disorder in twenty-five patients (92.5%) had previously not responded to stimulants. Atomoxetine, average dose 35.2 ± 24.4 mg, was given for a median of 26 weeks (range: 4-141). Seventeen patients (63%) discontinued atomoxetine due to: inadequate response (n=7, 26%), worsening behavior such as increased irritability/activation (n = 7, 26%), nonadherence (n=1, 4%), emerging psychotic-like symptoms (n=1, 4%), and appetite decrease and tremor (n=1, 4%). There were no discontinuations because of seizure exacerbation. Atomoxetine dose, epilepsy etiology, seizure type, and comorbid psychiatric disorders did not predict discontinuation. No safety problems of sufficient magnitude to preclude prospective studies of atomoxetine in children with epilepsy were found.

Eosinophilic hepatitis in an adolescent during lisdexamfetamine dimesylate treatment for ADHD

We describe here the case of an adolescent who developed eosinophilic hepatitis during treatment for attention-deficit/hyperactivity disorder with lisdexamfetamine dimesylate (Vyvanse [Shire US Inc, Wayne, PA]). A 14-year-old boy presented to his primary care provider with abdominal pain and worsening jaundice. A diagnosis of hepatitis was made with biochemical markers, but evaluation failed to provide an etiology. Worsening hepatitis prompted hospitalization and initiation of steroids for presumed autoimmune hepatitis. A subsequent liver biopsy showed evidence of eosinophilic hepatitis. Known causes of eosinophilic hepatitis were ruled out, and a presumptive diagnosis of reaction to lisdexamfetamine dimesylate was made. Discontinuation of the medication led to resolution of the hepatitis and normalization of the liver biopsy. To our knowledge, this is the first report of hepatic injury attributed to lisdexamfetamine dimesylate.

Use of atomoxetine in patients with attention-deficit hyperactivity disorder and co-morbid conditions

Attention-deficit hyperactivity disorder (ADHD) is one of the most common neurobehavioural disorders in children. It has been shown that as many as 85% of patients with ADHD have at least one psychiatric co-morbidity, and approximately 60% have at least two. Atomoxetine is a specific, noradrenergic reuptake inhibitor that provides an effective treatment option for patients with ADHD and co-morbid conditions. The efficacy of atomoxetine in treating ADHD appears to be unaffected by the presence of co-morbid conditions. Therapy with atomoxetine has been associated with statistically significant improvements in symptoms of oppositional defiant disorder in most, but not all, studies. Limited data suggest this agent may have potential in improving co-occurring symptoms of anxiety and may be useful in patients with co-morbid conditions such as tics or Tourette's syndrome. The tolerability profile of atomoxetine in patients with ADHD and co-morbid conditions was similar to that of patients with uncomplicated ADHD. Atomoxetine was well tolerated, with adverse events generally mild and transient; the most frequent adverse events in patients with ADHD included abdominal pain, decreased appetite, nausea and vomiting. The favourable safety and efficacy profile of atomoxetine makes it a promising treatment for patients with ADHD and associated co-morbidities.

Cytochrome P450 2D6 genotyping: potential role in improving treatment outcomes in psychiatric disorders

The specific reaction toward a given drug varies a lot between individuals and, for many drugs, pharmacogenetic polymorphisms are known to affect biotransformation and clinical outcome. Estimation of the individual's drug-metabolizing capacity can be undertaken by genotyping drug-metabolizing enzymes involved in the respective drug metabolism. Consequences that arise from genotyping may be the adjustment of dose according to genotype, choice of therapeutic strategy, or even choice of drug. One of the first fields where the clinical application of pharmacogenetics may be used is in that of antipsychotic and antidepressant drug treatment because there is a special need for individualized therapy in psychiatry. The pharmacokinetics of many TCAs, some SSRIs and other antidepressant drugs is significantly altered by polymorphisms; however, some controversy still exists as to whether therapeutic efficacy may be improved and/or adverse events can be prevented by genetically driven adjustment of drug dosage. Pharmacogenetic diagnostics may be an important factor in individualizing drug treatment according to the genetic make-up of the patients. However, routine application of pharmacogenetic dose adjustment in clinical practice requires prospective validation.

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.

Adverse effects of pharmacotherapies for attention-deficit hyperactivity disorder: epidemiology, prevention and management

Medication for the treatment of attention-deficit hyperactivity disorder (ADHD) is in widespread use globally. There is considerable data suggesting that overall, the adverse effect burden from this use is dose dependent and is in the mild to moderate category, but few comprehensive reviews exist of the epidemiology of adverse effects alone. This review provides a general and systems-specific summary of the scientific literature regarding adverse effect data for the drugs in general use for the treatment of ADHD. Although several areas lack definitive data, current evidence suggests that, for the majority of those treated for ADHD, the medications currently available pose little in the way of risk of significant harm. Epidemiological data suggest a low incidence of serious adverse effects, whilst the less serious adverse effects, such as insomnia and anorexia, are relatively common. Also, some specific areas of study suggest lower risks of harm than previously thought, e.g. tic disorders and seizures. However, pre-existing conditions and other interindividual differences may raise the risk of harmful adverse effects, which adds emphasis to the need for careful pretreatment assessment and monitoring. Potential but unlikely long-term treatment effects need to be investigated as carefully as possible, particularly with regard to cardiac sequelae and carcinogenesis. There are both overlaps and differences between the adverse effects of stimulants and nonstimulants, such as atomoxetine. For example, the latter shares the stimulant group's potential for changing cardiovascular parameters, but may not cause insomnia.

Efficacy and safety of atomoxetine for attention-deficit/hyperactivity disorder in children and adolescents-meta-analysis and meta-regression analysis

OBJECTIVES

The objective of this study was to evaluate the efficacy and safety of atomoxetine in children and adolescents.

MATERIALS AND METHODS

We searched for studies published between 1985 and 2006 through Medline, PubMed, PsychInfo and Cochrane Central Register of Controlled Trials (CENTRAL 2006 Issue 3) using keywords related to atomoxetine and attention-deficit/hyperactivity disorder (ADHD) and scanned though reference lists. We included nine randomized placebo-controlled trials (atomoxetine:placebo = 1,150:678).

RESULTS

Atomoxetine was superior (p < 0.01) to placebo in reducing ADHD symptoms across different scales (Attention-Deficit/Hyperactivity Disorder Rating Scale-IV, Conners' Parent and Teacher Rating Scales-Revised:Short Form, Clinical Global Impression-Severity) rated by different raters (parent, teacher, clinician). The number-needed-to-treat (NNTs) for treatment response and relapse prevention were 3.43 (95% CI, 2.79-4.45) and 10.30 (95% CI, 5.89-40.62), respectively. High baseline ADHD symptoms (p = 0.02) was associated with greater reduction in ADHD symptoms, whereas male gender (p = 0.02), comorbid oppositional defiant disorder (ODD) status (p = 0.01) and ADHD hyperactive/impulsive subtype (p = 0.01) were associated with smaller reductions. The commonest adverse events were gastrointestinal [appetite decrease, number-needed-to-harm (NNH) = 8.81; abdominal pain, NNH = 22.48; vomiting, NNH = 29.96; dyspepsia, NNH = 49.38] and sleep related (somnolence, NNH = 19.41). Young age (p = 0.03) and high baseline hyperactive/impulsive symptoms (p < 0.01) were associated with more adverse events, whereas ADHD inattentive subtype (p = 0.04) was associated with less adverse events. Quality of life using Child Health Questionnaire (CHQ) improved (p < 0.01) with atomoxetine treatment. Both ADHD and ODD symptoms (p < 0.01) were reduced in comorbid ADHD+ODD, and ODD status was not associated with more adverse events. Efficacy and side effects were not altered by comorbid general anxiety disorder or major depression.

CONCLUSIONS

Atomoxetine is efficacious in reducing ADHD symptoms. It may have a role in treating comorbid ODD or depression, and probably in comorbid anxiety.

Clinical assessment and treatment of ADHD in children

Attention-deficit/hyperactivity disorder is a highly diagnosed psychiatric disorder in children. This widespread and complex condition requires extensive evaluation involving clinicians, parents and teachers. Proper management involves individual assessment and treatment. Psychostimulants remain the primary medication of choice as they have been shown to be efficacious for this condition. Newer, long-acting medications are providing expanded options for children and their caregivers. Failure to assess and treat can lead to serious long-term effects later in life.

Pediatric atomoxetine ingestions reported to Texas poison control centers, 2003-2005

Limited information exists on potentially adverse consequences following pediatric atomoxetine ingestions reported to poison control centers. Using pediatric atomoxetine ingestions reported to Texas poison control centers during 2003-2005, the proportion of cases involving serious outcomes (medical outcomes classified as moderate effects, major effects, death, or judged as potentially toxic exposures) was determined for selected variables and evaluated for statistical significance by calculating the rate ratio (RR) and 95% confidence interval (CI). Of 501 cases identified, 31 (6%) involved serious outcomes. Higher serious outcome rates were found with a maximum dose of >2.8 mg/kg or >200 mg or >4 tablets. Serious outcome rates were also higher if the exposure involved intentional self-harm or the patient was already at or en route to a health care facility when the poison control center was contacted or referred to a health care facility by the poison control center. The severity of the outcome associated with pediatric atomoxetine ingestions was dependent upon the dose and the circumstances of the ingestion (whether intentional self-harm was involved). The management of patients with serious outcomes was more likely to involve health care facilities. This information is useful for creating triage guidelines for the management of pediatric atomoxetine ingestions.

Drug-induced liver disease in 2006

PURPOSE OF REVIEW

To identify the key publications of 2006 dealing with drug-induced liver injury.

RECENT FINDINGS

When given in therapeutic doses over 14 days, acetaminophen produced significant asymptomatic elevations in alanine aminotransferase among healthy volunteers, suggesting that subclinical injury may be more common than previously thought. Acute liver failure in children was shown to differ in several important respects from that seen in adults, notably a much lower incidence of acetaminophen toxicity with nearly half of all cases being indeterminate in origin. The first cases of hepatotoxicity with telithromycin, a new class of ketolide antibiotic, were described along with reports suggesting liver injury from ezetimibe among other agents. The potential for chronic injury to develop after acute drug-induced liver injury was analyzed in a large Swedish database; 5-6% of cases were judged to become chronic, with drugs causing cholestatic injury predominating. Among well described hepatotoxins, new reports appeared with highly active antiretroviral therapy agents, herbal therapies and several antibiotics. Finally, the safe use of pravastatin and pioglitazone was demonstrated in patients with chronic liver disease in controlled clinical trials.

SUMMARY

Drug-induced liver injury remains an important concern for many existing drugs as well as for agents in development.