Current and Investigational Medication Delivery Systems for Treating Attention-Deficit/Hyperactivity Disorder.

OBJECTIVE: To review currently available formulations and emphasize unmet needs in the pharmacologic management of attention-deficit/hyperactivity disorder (ADHD). DATA SOURCES: Publications and clinical trials were identified through PubMed and ClinicalTrials.gov, respectively. A Web-based search identified prescribing information for approved agents for treating ADHD, along with relevant guidelines and diagnostic criteria. STUDY SELECTION: The following search terms were used: (1) ADHD or attention-deficit/hyperactivity disorder or ADD or attention deficit hyperactivity disorder and/or (2) amphetamine or methylphenidate or atomoxetine or guanfacine or clonidine. Additional searches were performed using product brand names, and clinical trial was applied as a filter. Relevant studies were only included if published in English-language peer-reviewed journals and if involved agents were currently available (or pursuing approval) in the United States. Reviews of literature prior to 2005 and from 2005 to 2008 have been published previously; therefore, the present search focused on studies published from January 2009 through May 2016. In addition, reference lists of review articles and relevant studies were also examined to help identify additional studies. DATA EXTRACTION: A total of 578 publications were identified from the PubMed search, from which 426 publications were initially excluded based on review of the title and abstract. Reasons for exclusion included a focus on comorbid disorders, specific subpopulations, endpoints unrelated to improving ADHD symptomatology (eg, executive function, cognition, substance use), or quality of life measures. A more thorough assessment of the remaining citations, including publications and prescribing information, produced the final 219. RESULTS: Pharmacotherapy with stimulant and nonstimulant options is the most common approach for treating ADHD in adults and children. Stimulants are mostly formulated as either tablets or capsules; however, the newer generation includes transdermal patches, oral suspensions (liquids), chewable tablets, and orally disintegrating tablets. Nonstimulants are available in oral capsule (atomoxetine) and tablet (guanfacine and clonidine) formulations. CONCLUSIONS: Despite the broad range of treatment options currently available, nonadherence remains a significant problem in ADHD. While evidence is currently lacking, the availability of new formulations may improve adherence.

A double-blind, placebo-controlled study of selegiline transdermal system in depressed adolescents.

OBJECTIVE: A randomized, double-blind, placebo-controlled flexible-dose, parallel group trial was conducted at 26 clinical investigational sites in the United States to examine the safety and efficacy of the selegiline transdermal system (STS) (EMSAM®) in adolescents (ages 12-17 years) meeting American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria for moderate to severe major depressive disorder (MDD) without psychotic features. METHODS: Adolescents (n=308) with moderate to severe MDD were randomized to either STS (n=152) or placebo (n=156). Two hundred and fifteen (69.8%) subjects completed the study and 17 (5.5%) reported discontinuation because of adverse events (AEs). The primary efficacy outcome measure was the mean change from baseline to end of study (week 12 last observation carried forward [LOCF]) in the Children's Depression Rating Scale-Revised (CDRS-R) total score. Secondary outcome measures included end-point Clinical Global Impressions - Severity (CGI-S) and Clinical Global Impressions - Improvement (CGI-I). RESULTS: Patients on STS or placebo had a significant decline from baseline (p<0.001) on their CDRS-R total score with mean reductions±SD as follows: STS 21.4±16.6; placebo 21.5±16.5. Both groups had similar response rates (58.6% vs. 59.3%) defined as CGI-I of 1 or 2 at study end. However, these between-group efficacy findings were without statistical significance. The overall incidence of reported AEs was 62.5% for STS-treated patients and 57.7% for placebo-treated patients. Most commonly reported AEs in STS or placebo groups were application site reactions (STS=24.3%; placebo=21.8%), headache (STS=17.1%; placebo=16.7%), and nausea (STS=7.2%; placebo=7.7%). Treatment groups did not differ on any laboratory parameters, vital signs, or electrocardiogram (ECG) findings. No suspected hypertensive crises were reported in the trial. CONCLUSIONS: These data demonstrated that the STS was safe and well tolerated in this adolescent sample. However, both STS-treated and placebo-treated subjects demonstrated a decline from baseline in depressive symptoms (CDRS-R total score) over the length of the study, without statistical superiority by either group.

Randomized, double-blind, placebo-controlled, crossover study of the effects of lisdexamfetamine dimesylate and mixed amphetamine salts on cognition throughout the day in adults with attention-deficit/hyperactivity disorder.

BACKGROUND: Understanding the nature and time course of the pharmacodynamic effects of attention-deficit/hyperactivity disorder (ADHD) medications is useful. The Cognitive Drug Research Computerized Battery of Tests (CDR-CBT) is a 20-min battery of ten standardized, validated neuropsychometric tasks. OBJECTIVE: This pilot study examined the sensitivity and responsiveness of the CDR-CBT for assessing cognitive function in adults with ADHD prior to and up to 16 h postdose during treatment with lisdexamfetamine dimesylate (LDX) or mixed amphetamine salts immediate release (MAS-IR; various generics available). METHODS: This was a double-blind three-period crossover study. Participants received LDX 50 mg/day, MAS-IR 20 mg/day, and placebo (~7 a.m.) for 7 days each in randomized order. CDR-CBT was administered on day 1 of period 1 and day 7 of each period at scheduled times between -0.5 (predose) and 16 h postdose. Composite power of attention (PoA) score (sum of simple reaction time, choice reaction time, and digit vigilance speed) was the primary outcome measure. The Conners' Adult ADHD Rating Scales-Self-Report: Short Version (CAARS-S:S) was administered at baseline and on day 1 of period 1, and days 6 and 7 of each treatment period. Tertiary outcomes included CDR-CBT composite continuity of attention scores, its component task scores, cognitive reaction time, and response variability scores. No inferential statistical comparisons were conducted. Safety assessments included adverse events (AEs) and vital signs. RESULTS: This analysis included 18 participants (mean age 30.8 years); one withdrew because of AEs. Mean pretreatment PoA scores were 1175.9-1361.2 ms, scores commensurate with a normative age of >40 years. Maximum reductions in PoA scores with LDX and MAS-IR occurred at 5 h postdose at day 7 (least squares mean difference [95% CI] of -150.0 [-235.41 to -64.50] and -79.8 [-165.72 to 6.21] ms vs. placebo, respectively). CAARS-S:S scores were unchanged with LDX and MAS-IR (vs. placebo) at all postdose timepoints. Tertiary attention-related CDR-CBT outcomes were sensitive to LDX and MAS-IR (vs. placebo). Treatment-emergent AEs and vital signs were consistent with previous studies in adult ADHD. CONCLUSION: In adults with ADHD, PoA scores indicated impaired attention at baseline and response to treatment with LDX and MAS-IR (vs. placebo), demonstrating value for measuring the time course of pharmacologic treatment effects.

Treatment outcomes with lisdexamfetamine dimesylate in children who have attention-deficit/hyperactivity disorder with emotional control impairments.

OBJECTIVE: The purpose of this study was to assess lisdexamfetamine dimesylate (LDX) treatment effects based on baseline emotional control dysfunction in children with attention-deficit/hyperactivity disorder (ADHD) categorized with or without impairments of executive function (EF) emotional control. METHODS: Post-hoc analyses of a 7 week, open-label LDX study in children with ADHD (American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision [DSM-IV-TR] defined) and impairments in EF control of emotional response. At baseline, participants were dichotomized by Behavior Rating Inventory of EF (BRIEF) emotional control domain T-scores of ≥65 (with impairment) or <65 (without impairment). ADHD Rating Scale-IV (ADHD-RS-IV), BRIEF Global Executive Composite and emotional control domain, Expression and Emotion Scale for Children (EESC) scores, Pearson correlations for BRIEF versus ADHD-RS-IV and EESC, and Clinical Global Impressions scores were assessed at baseline and end of study (week 7)/early termination (EOS/ET) by baseline category of BRIEF emotional control impairment. Safety assessments included treatment-emergent adverse events (TEAEs). RESULTS: At baseline and EOS/ET, respectively, 53.0% and 20.7% met criteria for emotional control impairment. Participants with and without emotional control impairments had similar ADHD-RS-IV change scores. Mean (SD) change from baseline for those with and without emotional control impairments were -20.8 (12.89) and -14.6 (11.25) for BRIEF global scores and -16.0 (13.19) and -5.0 (9.48) for BRIEF emotional control domain scores. Participants with emotional control impairments had greater mean EESC total score changes. BRIEF emotional control domain and all ADHD-RS-IV scores indicated moderate correlations between change scores (all p<0.0001). Overall, 84.9% of participants had TEAEs (mostly mild-to-moderate in severity); 3.8% discontinued because of TEAEs. CONCLUSIONS: The proportion of children with behavioral impairments in EF control of emotional response decreased during LDX treatment. ADHD symptoms improved in both groups. The moderate correlations between EF behaviors and ADHD symptoms suggest there may be utility in evaluating behavioral domains beyond core ADHD symptoms.

Clinically relevant changes in emotional expression in children with ADHD treated with lisdexamfetamine dimesylate.

OBJECTIVE: To describe clinically relevant effects of lisdexamfetamine dimesylate (LDX) on emotional expression (EE) in children with ADHD. METHOD: Children with ADHD participated in a 7-week, open-label, LDX dose-optimization study. Expression and Emotion Scale for Children (EESC) change scores were analyzed post hoc using two methods to determine proportion of participants with different categories of clinical response based on (a) clinically significant (movement >2 SD from baseline mean)/reliable change (not due to measurement error) and (b) standard error of measurement (SEM) as a measure of clinically meaningful change. RESULTS: With LDX, no participants showed clinically significant/reliable improvement; 0.7% showed clinically significant/reliable deterioration of EE by reliable change index and movement from baseline mean. One third of participants had improved EE by SEM criteria; 9.2% had categorical worsening. CONCLUSION: Using clinically meaningful change and clinically significant/reliable change categories derived from the EESC, most participants had no worsening of EE with LDX.

Long-term treatment outcomes with lisdexamfetamine dimesylate for adults with attention-deficit/hyperactivity disorder stratified by baseline severity.

OBJECTIVE: To examine the impact of baseline severity on lisdexamfetamine dimesylate (LDX) efficacy in a long-term study of adults with attention-deficit/hyperactivity disorder (ADHD). RESEARCH DESIGN AND METHODS: Adults from a 4-week, placebo-controlled, forced dose-escalation study with LDX (30-70 mg/day) or placebo were enrolled in a long-term, open-label dose-optimization study for an additional 12 months. In post hoc analyses, participants were stratified by baseline severity (from the prior short-term study) with Clinical Global Impressions-Severity (CGI-S) scores of 4 (moderately), 5 (markedly), or ≥6 (severely/extremely ill). ADHD-Rating Scale IV (ADHD-RS-IV) with adult prompts (primary) and CGI-Improvement (CGI-I) were used to assess effectiveness. Clinical response was defined as a ≥30% decrease in ADHD-RS-IV from baseline and a CGI-I of 1 or 2; symptomatic remission was defined as ADHD-RS-IV ≤18. Treatment-emergent adverse events (TEAEs) were monitored. RESULTS: Participants had baseline CGI-S scores of 4 (n = 114), 5 (n = 188), or ≥6 (n = 43). At endpoint, mean (SD) change from baseline in ADHD-RS-IV was greater (p < 0.0001) for participants with CGI-S = 5 (-26.4 [11.77]) and ≥6 (-32.3 [9.81]) than for participants with CGI-S = 4 (-19.5 [9.97]). At endpoint, 81.6%, 84.6%, and 88.4% of participants were very much/much improved (CGI-I of 1 or 2) in CGI-S categories of 4, 5, and ≥6, respectively. Clinical response criteria were met by 78.9%, 83.5%, and 88.4% and symptomatic remission criteria by 64.0%, 65.4%, and 72.1% of participants with CGI-S = 4, 5, and ≥6, respectively. The most frequently reported TEAEs with participant incidence ≥10% for any LDX dose were upper respiratory tract infection (21.8%), insomnia (19.5%), headache (17.2%), dry mouth (16.6%), decreased appetite (14.3%), and irritability (11.2%). CONCLUSIONS: Some aspects of these analyses (e.g., open-label design without placebo control, inclusion and exclusion criteria of the demographic profile of participants, and the post hoc nature of the statistical analysis) limit interpretation. However, long-term LDX treatment demonstrated increased degree of symptom improvement with greater baseline symptom severity. Rates of clinical response and symptomatic remission tended to be greater for those with greater baseline severity. LDX demonstrated a safety profile consistent with long-acting stimulant use.

A 6-month, open-label, extension study of the tolerability and effectiveness of the methylphenidate transdermal system in adolescents diagnosed with attention-deficit/hyperactivity disorder.

OBJECTIVE: The aim of this study was to evaluate the tolerability and effectiveness of the methylphenidate transdermal system (MTS) over 6 months in adolescents with attention-deficit/hyperactivity disorder (ADHD). METHODS: This was an industry-sponsored, 30-center, open-label study of subjects aged 13-17 years with ADHD. Subjects were dose-optimized with MTS (10-30 mg/9 hours) over 5 weeks and then dose-maintained for up to 5 months. Tolerability evaluations included treatment-emergent adverse events (TEAEs) and dermal responses. Effectiveness was assessed with the ADHD-Rating Scale-IV (ADHD-RS-IV). RESULTS: A total of 162 subjects received MTS treatment. The majority of TEAEs (>99%) were mild or moderate in intensity, and the most frequently reported TEAE was decreased appetite (15.4%). Thirteen subjects discontinued the study due to TEAEs. The majority (93.6%) of dermatologic reactions indicated mild erythema. There was significant improvement in mean ADHD-RS-IV total scores from study entry to end point (p<0.001). CONCLUSION: Slightly more than half (54.0%) of subjects completed this 6-month, open-label extension study of MTS; the primary reason for discontinuation was withdrawn consent (36.0%). Reported TEAEs and skin tolerability findings were similar to those observed with MTS use in children and adolescents. MTS treatment resulted in a decrease in ADHD symptoms as rated by clinicians.

Single- and multiple-dose pharmacokinetics of methylphenidate administered as methylphenidate transdermal system or osmotic-release oral system methylphenidate to children and adolescents with attention deficit hyperactivity disorder.

This was a 1-month, multicenter, open-label, randomized study to determine single- and multiple-dose pharmacokinetics of d,l-methylphenidate (MPH) after MPH transdermal system (MTS) and osmotic-release oral system MPH (OROS MPH) dosing in children (6-12 years) and adolescents (13-17 years) who had a diagnosis of attention deficit hyperactivity disorder. The pharmacokinetic population consisted of 33 children and 31 adolescents. Accumulation of d-MPH was 34% in children and 57% in adolescents after multiple fixed doses of MTS for 7 days and 76% and 94%, respectively, after 28 days of dosing. After 7 days of OROS MPH dosing, accumulation was 16% in children and 19% in adolescents; fixed doses of OROS MPH were not studied beyond 7 days. After escalating the doses to 30 mg per 9 hours for MTS, accumulation was 73% in children and 83% in adolescents after allowing for dose escalation. Corresponding values for OROS MPH after dose escalation to 54 mg were 33% in both age groups. Plasma l-MPH concentrations were approximately half those of d-MPH for MTS and negligible for OROS MPH. Overall, MTS accumulation was above that expected for single-dose pharmacokinetics of MTS and OROS MPH in both age groups. As a result of accumulation, systemic exposure to d-MPH in children after multiple escalating doses was 1.4- to 1.6-fold higher for MTS compared with OROS MPH, but similar in adolescents for both formulations. After all dosing, systemic exposure was greater in children compared with adolescents, consistent with lower body weight in children. Adverse events were mild to moderate for both formulations, and MTS dermal responses were mild.

Brain-to-serum lithium ratio and age: an in vivo magnetic resonance spectroscopy study.

OBJECTIVE: The authors' goal was to determine if there is an association between brain-to-serum lithium ratios and age. METHOD: Lithium-7 magnetic resonance spectroscopy was used to measure in vivo brain lithium levels in nine children and adolescents (mean age=13.4 years, SD=3.6) and 18 adults (mean age=37.3, SD=9.1) with bipolar disorder. RESULTS: Serum and brain lithium concentrations were positively correlated. Younger subjects had lower brain-to-serum concentration ratios than adults: 0.58 (SD=0.24) versus 0.92 (SD=0.36). The brain-to-serum concentration ratio correlated positively with age. CONCLUSIONS: These observations suggest that children and adolescents may need higher maintenance serum lithium concentrations than adults to ensure that brain lithium concentrations reach therapeutic levels.