A postmarketing clinical experience study of Metadate CD

Thermoresponsive gating membranes embedded with liquid crystal(s) for pulsatile transdermal drug delivery: An overview and perspectives

Due to the circadian rhythm regulation of almost every biological process in the human body, physiological and biochemical conditions vary considerably over the course of a 24-h period. Thus, optimal drug delivery and therapy should be effectively controlled to achieve the desired therapeutic plasma concentrations and therapeutic drug responses at the required time according to chronopharmacological concepts, rather than continuous maintenance of constant drug concentrations for an extended time period. For many drugs, it is not always necessary to constantly deliver a drug into the human body under disease conditions due to rhythmic variations. Pulsatile drug delivery systems (PDDSs) have been receiving more attention in pharmaceutical development by providing a predetermined lag period, followed by a fast or rate-controlled drug release after application. PDDSs are characterized by a programmed drug release, which may release a drug at repeatable pulses to match the biological and clinical needs of a given disease therapy. This review article focuses on thermoresponsive gating membranes embedded with liquid crystals (LCs) for transdermal drug delivery using PDDS technology. In addition, the principal rationale and the advanced approaches for the use of PDDSs, the marketed products of chronotherapeutic DDSs with pulsatile function designed by various PDDS technologies, pulsatile drug delivery designed with thermoresponsive polymers, challenges and opportunities of transdermal drug delivery, and novel approaches of LC systems for drug delivery are reviewed and discussed. A brief overview of all academic research articles concerning single LC- or binary LC-embedded thermoresponsive membranes with a switchable on-off permeation function through topical application by an external temperature control, which may modulate the dosing interval and administration time according to the therapeutic needs of the human body, is also compiled and presented. In the near future, since thermal-based approaches have become a well-accepted method to enhance transdermal delivery of different water-soluble drugs and macromolecules, a combination of the thermal-assisted approach with thermoresponsive LCs membranes will have the potential to improve PDDS applications but still poses a great challenge.

Methylphenidate for attention deficit hyperactivity disorder (ADHD) in children and adolescents - assessment of adverse events in non-randomised studies

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in childhood. The psychostimulant methylphenidate is the most frequently used medication to treat it. Several studies have investigated the benefits of methylphenidate, showing possible favourable effects on ADHD symptoms, but the true magnitude of the effect is unknown. Concerning adverse events associated with the treatment, our systematic review of randomised clinical trials (RCTs) demonstrated no increase in serious adverse events, but a high proportion of participants suffered a range of non-serious adverse events.

OBJECTIVES

To assess the adverse events associated with methylphenidate treatment for children and adolescents with ADHD in non-randomised studies.

SEARCH METHODS

In January 2016, we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, 12 other databases and two trials registers. We also checked reference lists and contacted authors and pharmaceutical companies to identify additional studies.

SELECTION CRITERIA

We included non-randomised study designs. These comprised comparative and non-comparative cohort studies, patient-control studies, patient reports/series and cross-sectional studies of methylphenidate administered at any dosage or formulation. We also included methylphenidate groups from RCTs assessing methylphenidate versus other interventions for ADHD as well as data from follow-up periods in RCTs. Participants had to have an ADHD diagnosis (from the 3rd to the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders or the 9th or 10th edition of theInternational Classification of Diseases, with or without comorbid diagnoses. We required that at least 75% of participants had a normal intellectual capacity (intelligence quotient of more than 70 points) and were aged below 20 years. We excluded studies that used another ADHD drug as a co-intervention.

DATA COLLECTION AND ANALYSIS

Fourteen review authors selected studies independently. Two review authors assessed risk of bias independently using the ROBINS-I tool for assessing risk of bias in non-randomised studies of interventions. All review authors extracted data. We defined serious adverse events according to the International Committee of Harmonization as any lethal, life-threatening or life-changing event. We considered all other adverse events to be non-serious adverse events and conducted meta-analyses of data from comparative studies. We calculated meta-analytic estimates of prevalence from non-comparative cohorts studies and synthesised data from patient reports/series qualitatively. We investigated heterogeneity by conducting subgroup analyses, and we also conducted sensitivity analyses.

MAIN RESULTS

We included a total of 260 studies: 7 comparative cohort studies, 6 of which compared 968 patients who were exposed to methylphenidate to 166 controls, and 1 which assessed 1224 patients that were exposed or not exposed to methylphenidate during different time periods; 4 patient-control studies (53,192 exposed to methylphenidate and 19,906 controls); 177 non-comparative cohort studies (2,207,751 participants); 2 cross-sectional studies (96 participants) and 70 patient reports/series (206 participants). Participants' ages ranged from 3 years to 20 years. Risk of bias in the included comparative studies ranged from moderate to critical, with most studies showing critical risk of bias. We evaluated all non-comparative studies at critical risk of bias. The GRADE quality rating of the evidence was very low.Primary outcomesIn the comparative studies, methylphenidate increased the risk ratio (RR) of serious adverse events (RR 1.36, 95% confidence interval (CI) 1.17 to 1.57; 2 studies, 72,005 participants); any psychotic disorder (RR 1.36, 95% CI 1.17 to 1.57; 1 study, 71,771 participants); and arrhythmia (RR 1.61, 95% CI 1.48 to 1.74; 1 study, 1224 participants) compared to no intervention.In the non-comparative cohort studies, the proportion of participants on methylphenidate experiencing any serious adverse event was 1.20% (95% CI 0.70% to 2.00%; 50 studies, 162,422 participants). Withdrawal from methylphenidate due to any serious adverse events occurred in 1.20% (95% CI 0.60% to 2.30%; 7 studies, 1173 participants) and adverse events of unknown severity led to withdrawal in 7.30% of participants (95% CI 5.30% to 10.0%; 22 studies, 3708 participants).Secondary outcomesIn the comparative studies, methylphenidate, compared to no intervention, increased the RR of insomnia and sleep problems (RR 2.58, 95% CI 1.24 to 5.34; 3 studies, 425 participants) and decreased appetite (RR 15.06, 95% CI 2.12 to 106.83; 1 study, 335 participants).With non-comparative cohort studies, the proportion of participants on methylphenidate with any non-serious adverse events was 51.2% (95% CI 41.2% to 61.1%; 49 studies, 13,978 participants). These included difficulty falling asleep, 17.9% (95% CI 14.7% to 21.6%; 82 studies, 11,507 participants); headache, 14.4% (95% CI 11.3% to 18.3%; 90 studies, 13,469 participants); abdominal pain, 10.7% (95% CI 8.60% to 13.3%; 79 studies, 11,750 participants); and decreased appetite, 31.1% (95% CI 26.5% to 36.2%; 84 studies, 11,594 participants). Withdrawal of methylphenidate due to non-serious adverse events occurred in 6.20% (95% CI 4.80% to 7.90%; 37 studies, 7142 participants), and 16.2% were withdrawn for unknown reasons (95% CI 13.0% to 19.9%; 57 studies, 8340 participants).

AUTHORS' CONCLUSIONS

Our findings suggest that methylphenidate may be associated with a number of serious adverse events as well as a large number of non-serious adverse events in children and adolescents, which often lead to withdrawal of methylphenidate. Our certainty in the evidence is very low, and accordingly, it is not possible to accurately estimate the actual risk of adverse events. It might be higher than reported here.Given the possible association between methylphenidate and the adverse events identified, it may be important to identify people who are most susceptible to adverse events. To do this we must undertake large-scale, high-quality RCTs, along with studies aimed at identifying responders and non-responders.

Participant satisfaction in a study of stimulant, parent training, and risperidone in children with severe physical aggression

OBJECTIVE

The purpose of this study was to examine the satisfaction of families who participated in the Treatment of Severe Childhood Aggression (TOSCA) study.

METHODS

TOSCA was a randomized clinical trial of psychostimulant plus parent training plus placebo (basic treatment) versus psychostimulant plus parent training plus risperidone (augmented treatment) for children with severe physical aggression, disruptive behavior disorder, and attention-deficit/hyperactivity disorder. Parents completed a standardized Parent Satisfaction Questionnaire (PSQ).

RESULTS

Of the 168 families randomized, 150 (89.3%) provided consumer satisfaction data. When they were asked if they would join the study again if they had the option to repeat, 136 (91%) said "yes," 11 (7%) said "maybe," and one (<1%) said "no." When asked if they would recommend the study to other parents with children having similar problems, 147 (98%) said "yes" and 3 (2%) said "maybe." Between 71% (rating one aspect of the Parent Training) and 96% (regarding the diagnostic interview) endorsed study procedures using the most positive response option. Asked if there were certain aspects of the study that they especially liked, 64 (43%) spontaneously reported parent training. Treatment assignment (basic vs. augmented) and responder status were not associated with reported satisfaction. However, responder status was strongly associated with parent confidence in managing present (p<0.001) and future (p<0.005) problem behaviors.

CONCLUSIONS

These findings indicate high levels of satisfaction with TOSCA study involvement and, taken together with previous pediatric psychopharmacology social validity studies, suggest high levels of support for the research experience. These findings may inform research bioethics and may have implications for deliberations of institutional review boards.

TRIAL REGISTRY

Treatment of Severe Childhood Aggression (The TOSCA Study), NCT00796302, clinicaltrials.gov .

Toward quality care in ADHD: defining the goals of treatment

OBJECTIVE

Therapeutic goals for chronic mental disorders like major depressive disorder (MDD) and schizophrenia have evolved in parallel with the growing medical knowledge about the course and treatment of these disorders. Although the knowledge base regarding the clinical course of ADHD, a chronic psychiatric disorder, has evolved beyond symptomatic improvement and short-term treatment response, long-term goals, such as functional remission, have not yet been clearly defined.

METHOD

A PubMed literature search was conducted to investigate the therapeutic goals of pharmacologic treatment referenced in the published literature from January 1998 through February 2010 using the following commonly used ADHD treatments as keywords: amphetamine, methylphenidate, atomoxetine, lisdexamfetamine, guanfacine, and clonidine. This search was then combined with an additional search that included the following outcome keywords: remission, relapse, remit, response, normal, normalization, recovery, and effectiveness.

RESULTS

Our search identified 102 publications. The majority (88.2% [90/102]) of these contained predefined criteria for treatment response. Predefined criteria for normalization and remission and/or relapse were presented in 4.9% (5/102), 12.7% (13/102), and 3.9% (4/102) of publications, respectively. There was a lack of consistency between the instruments used to measure outcomes as well as the criteria used to define treatment response, normalization, and remission as well as relapse.

CONCLUSION

The therapeutic goals in treating ADHD should address optimal treatment outcomes that go beyond modest reductions of ADHD symptoms to include syndromatic, symptomatic, and functional remission. Future work should focus on reliable and valid tools to measure these outcomes in the clinical trial setting.

Long-acting methylphenidate formulations in the treatment of attention-deficit/hyperactivity disorder: a systematic review of head-to-head studies

BACKGROUND

The stimulant methylphenidate (MPH) has been a mainstay of treatment for attention-deficit/hyperactivity disorder (ADHD) for many years. Owing to the short half-life and the issues associated with multiple daily dosing of immediate-release MPH formulations, a new generation of long-acting MPH formulations has emerged. Direct head-to-head studies of these long-acting MPH formulations are important to facilitate an evaluation of their comparative pharmacokinetics and efficacy; however, to date, relatively few head-to-head studies have been performed.The objective of this systematic review was to compare the evidence available from head-to-head studies of long-acting MPH formulations and provide information that can guide treatment selection.

METHODS

A systematic literature search was conducted in MEDLINE and PsycINFO in March 2012 using the MeSH terms: attention deficit disorder with hyperactivity/drug therapy; methylphenidate/therapeutic use and All Fields: Concerta; Ritalin LA; OROS and ADHD; Medikinet; Equasym XL and ADHD; long-acting methylphenidate; Diffucaps and ADHD; SODAS and methylphenidate. No filters were applied and no language, publication date or publication status limitations were imposed. Articles were selected if the title indicated a comparison of two or more long-acting MPH preparations in human subjects of any age; non-systematic review articles and unpublished data were not included.

RESULTS

Of 15,295 references returned in the literature search and screened by title, 34 articles were identified for inclusion: nine articles from pharmacokinetic studies (nine studies); nine articles from laboratory school studies (six studies); two articles from randomized controlled trials (two studies); three articles from switching studies (two studies) and three articles from one observational study.

CONCLUSIONS

Emerging head-to-head studies provide important data on the comparative efficacy of the formulations available. At a group level, efficacy across the day generally follows the pharmacokinetic profile of the MPH formulation. No formulation is clearly superior to another; careful consideration of patient needs and subtle differences between formulations is required to optimize treatment. For patients achieving suboptimal symptom control, switching long-acting MPH formulations may be beneficial. When switching formulations, it is usually appropriate to titrate the immediate-release component of the formulation; a limitation of current studies is a focus on total daily dose rather than equivalent immediate-release components. Further studies are necessary to provide guidance in clinical practice, particularly in the treatment of adults and pre-school children and the impact of comorbidities and symptom severity on treatment response.

What contributes to patient and parent satisfaction with medication in the treatment of children with ADHD? A report on the development of a new rating scale

Satisfaction with medication is important in the evaluation of overall treatment outcome. There is a lack of consistent and validated rating scales for satisfaction with medication in ADHD, therefore comparison across studies is difficult. Here, we analyse the psychometric properties of the satisfaction with medication scale (SAMS), a new item-based questionnaire that assesses satisfaction with ADHD medication. Furthermore, we evaluate the predictive effect of ADHD symptoms and quality of life (QoL) on satisfaction. Data on satisfaction with Equasym XL(®) (methylphenidate) were collected in the OBSEER study using the parent (SAMS-P, n = 589) and patient (SAMS-S, n = 552) versions of the SAMS questionnaire. Internal consistency, item-total and cross-informant correlations, and the stability of satisfaction ratings over time were assessed. Satisfaction with medication scores were then correlated with ratings of ADHD symptoms and QoL. Rates of overall satisfaction with Equasym XL(®) among parents and children were high (>70%), as was internal consistency for both SAMS-P and SAMS-S (Cronbach's alpha > 0.9). Similarly, item-total correlations were high (r = 0.71-0.90) for SAMS-P and medium-high (r = 0.57-0.77) for SAMS-S. Cross-informant correlations and the stability of satisfaction ratings were moderate (r = 0.54-0.59 and 0.48-0.60, respectively). ADHD symptom and QoL ratings were significantly negative and positive predictors of satisfaction, explaining 36-52% of satisfaction variance at the final visit. The results show that parent and patient satisfaction was high and could be assessed reliably with the new SAMS questionnaire. Parent and patient ratings were moderately correlated, and symptom severity, functional impairment and QoL were the most significant predictors of satisfaction.

An observational study of once-daily modified-release methylphenidate in ADHD: effectiveness on symptoms and impairment, and safety

ADHD affects over 5% of children worldwide. It is typically treated with stimulant medications, and methylphenidate (MPH) is the most commonly prescribed. This study investigated the effectiveness, on symptoms and impairment, and safety of Equasym XL(®), a combination of 30% immediate-release and 70% modified-release MPH, in the treatment of ADHD in daily clinical practice. This open-label, observational, post-marketing surveillance study was conducted in 169 centres in Germany. Eligible patients, aged 6-17 years, were diagnosed with ADHD and about to begin treatment with Equasym XL(®). Effectiveness was assessed by physicians using the clinical global impression (CGI) severity and improvement scales; teachers and parents completed questionnaires evaluating ADHD symptoms and behavioural problems (DAYAS, FBB-ADHD and SDQ-P). Assessments were carried out at baseline, after 1-3 and 6-12 weeks of treatment. Of 852 enrolled patients, 822 were evaluable; 25.30% were treatment naïve, 69.84% had previously received different MPH formulations, and 4.87% had received other medications. ADHD symptoms improved from baseline to last visit for the majority of patients for all outcome measures. According to physician ratings of core ADHD symptoms, 75.73% of patients showed improvements on the CGI-Improvement scale, 17.77% had no change, and 6.50% worsened. In teacher and parent ratings, the effectiveness of Equasym XL(®) was rated better than prior therapy at all measured time points across the day, particularly late morning (teachers) and early afternoon (parents). Equasym XL(®) was generally well tolerated; only 3.16% of patients permanently discontinued treatment due to adverse events. Equasym XL(®) is effective and well tolerated in daily clinical practice.

Editorial: Observational studies in ADHD: the effects of switching to modified-release methylphenidate preparations on clinical outcomes and adherence

Patients with ADHD may have better adherence to treatment with modified-release methylphenidate (MPH-MR) formulations, which are taken once daily, compared with immediate-release (IR) formulations, which need to be taken several times a day. Data on long-term outcomes such as adherence may be lacking from randomised controlled trials as these are usually only short-term. Observational studies, if performed and reported appropriately, can provide valuable long-term data on such outcomes, as well as additional information on effectiveness and efficiency, from a real-life setting. By reviewing previous observational studies that have investigated switching treatment from MPH-IR to MPH-MR, results from a new, naturalistic observational study, the OBSEER study, are put into context. We conclude that, based on observational trial data, switching from MPH-IR to MPH-MR is a valid clinical approach, with the potential for improved clinical outcome and treatment adherence.

Emerging drugs for attention-deficit/hyperactivity disorder

Symptoms of attention-deficit/hyperactivity disorder (ADHD) are heterogeneous and often accompanied by comorbid psychiatric disorders. Although symptoms tend to lessen with age, many patients continue to be affected by the disorder into adulthood. Although many medications are available to treat ADHD, it is unlikely that a single medication will ever be developed to work for all patients. Recent advances, such as long-acting, extended-release formulations and transdermal delivery systems, have lengthened the duration of effectiveness, which has increased compliance and eliminated the need for additional medication dosing during the school or work day. Additional safe, well-tolerated, long-acting medications with further reduced potential for diversion and abuse are needed. Catecholamine pathways and their effect on executive functions and ADHD symptom control have been productive areas of research. Potential therapies such as adrenergic receptor agonists, glutamatergic agents, GABA receptor antagonists and nicotine receptor agonists are being explored as future pharmacotherapies for ADHD.

Hematologic and blood biochemistry monitoring during methylphenidate treatment in children with attention-deficit/hyperactivity disorder: 2-year, open-label study results

OBJECTIVES

Patients receiving methylphenidate for the management of attention-deficit/hyperactivity disorder are recommended to receive periodic hematologic monitoring. The objective of this study was to evaluate the long-term effects of methylphenidate treatment on blood biochemistry and hematologic values.

METHODS

This study involved a detailed analysis of changes in hematologic and blood biochemistry values over the course of a 2-year study of once-daily OROS methylphenidate in otherwise healthy children aged 6 to 13 years with attention-deficit/hyperactivity disorder. Routine hematologic and blood biochemistry assessments were performed at baseline, at 6 and 12 months during study treatment, and at the end of the study.

RESULTS

Of the 407 subjects enrolled in the study, 289 completed year 1, and 229 completed 21 of 24 months. No subject was excluded from entry into the study or discontinued from the study because of abnormalities of any of the blood chemistries evaluated. There were no clinically significant changes from baseline in mean values for hematologic or blood biochemistry parameters. For most values, the mean change in value over the course of the study was <5%.

CONCLUSIONS

These longer-term data suggest that chronic therapy with OROS methylphenidate has no clinically significant impact on laboratory values, challenging the necessity of routine hematologic monitoring in otherwise healthy children with attention-deficit/hyperactivity disorder who are treated with methylphenidate.

Spotlight on methylphenidate controlled-delivery capsules (Equasym XL, Metadate CD) in the treatment of children and adolescents with attention-deficit hyperactivity disorder

Controlled-delivery methylphenidate (methylphenidate CD) [Equasym XL, Metadate CD], an oral stimulant, is approved in the US and EU to treat children aged > or = 6 years who have been diagnosed with attention-deficit hyperactivity disorder (ADHD). Once-daily methylphenidate CD is generally well tolerated and effective in the treatment of children and adolescents with ADHD. Methylphenidate CD resulted in superior control of ADHD symptoms compared with osmotic release oral system (OROS) methylphenidate over a time period corresponding to that of an average school day in a laboratory classroom. In 3-week clinical trials conducted in a community setting, methylphenidate CD was superior to placebo and non-inferior to methylphenidate immediate-release in the treatment of children and adolescents with ADHD. Thus, methylphenidate CD should be considered an important primary treatment on its own or in addition to behavioural and psychosocial interventions, for when a reduction in ADHD symptoms is required during the school day in preference to the evening.

Parent satisfaction in a multi-site acute trial of risperidone in children with autism: a social validity study

RATIONALE

Subjects who view experimental procedures as worthwhile are more likely to participate in clinical trials and comply with study procedures. Designing studies that consider the consumer's perspective will help to forge a better alliance between participants and researchers.

OBJECTIVE

Participant satisfaction is seldom assessed in pharmacological research. In this paper, we report on parent satisfaction in a randomized clinical trial in children with autistic disorder and severely disruptive behavior.

METHOD

Parents of 101 children with autism who had participated in a multi-site 8-week double-blind clinical trial of risperidone were given a questionnaire at the end to elicit their perceptions of the appropriateness and acceptability of clinical trial procedures.

RESULTS

Ninety-six (95.0%) parents returned the questionnaire. Of these, 80.0 to 96.8%, depending on the question, expressed satisfaction with their child's research participation regardless of treatment outcome or assignment to active drug or placebo. In all, 90.5% of parents indicated that they would "definitely" recommend the clinical trial to other families with similar children. A total of 92.7% indicated that they would rejoin the clinical trial if they had to do it all over again. Ethnic minority subjects were more satisfied than white participants with the use of "learning tests".

CONCLUSIONS

Parents of children participating in this trial were highly satisfied and supportive of the clinical trial procedures. Random assignment to drug or placebo and the clinical response of their children did not appear to influence their views. Further satisfaction studies of this sort are encouraged.

Methylphenidate controlled-delivery capsules (EquasymXL, Metadate CD): a review of its use in the treatment of children and adolescents with attention-deficit hyperactivity disorder

Controlled-delivery methylphenidate (methylphenidate CD) [EquasymXL, Metadate CD], an oral stimulant, is approved in the US and EU to treat children aged>or=6 years who have been diagnosed with attention-deficit hyperactivity disorder (ADHD). Once-daily methylphenidate CD is generally well tolerated and effective in the treatment of children and adolescents with ADHD. Methylphenidate CD resulted in superior control of ADHD symptoms compared with osmotic release oral system (OROS) methylphenidate over a time period corresponding to that of an average school day in a laboratory classroom. In 3-week clinical trials conducted in a community setting, methylphenidate CD was superior to placebo and noninferior to methylphenidate immediate-release (IR) in the treatment of children and adolescents with ADHD. Thus, methylphenidate CD should be considered an important primary treatment on its own or in addition to behavioral and psychosocial interventions, for when a reduction in ADHD symptoms is required during the school day in preference to the evening.

Comparison of the clinical efficacy of twice-daily Ritalin and once-daily Equasym XL with placebo in children with Attention Deficit/Hyperactivity Disorder

OBJECTIVE

To compare the efficacy and safety of two methylphenidate (MPH) formulations--once-daily modified-release MPH (EqXL, Equasym XL) and twice-daily immediate-release methylphenidate (MPH-IR, Ritalin)--and placebo in children with Attention Deficit/Hyperactivity Disorder (ADHD).

METHODS

Children aged 6-12 years on a stable dose of MPH were randomized into a double-blind, three-arm, parallel-group, multi-center study and received 3 weeks of EqXL (20, 40, or 60 mg qd), MPH-IR (10, 20, or 30 mg bid) or placebo. Non-inferiority of EqXL to MPH-IR was assessed by the difference in the inattention/overactivity component of the overall teacher's IOWA Conners' Rating Scale on the last week of treatment (per protocol population). Safety was monitored by adverse events, laboratory parameters, vital signs, physical exam, and a Side Effect Rating Scale.

RESULTS

The lower 97.5% confidence interval bound of the difference between MPH groups fell above the non-inferiority margin (-1.5 points) not only during the last week of treatment but during all three treatment weeks. Both MPH-treatment groups experienced superior benefit when compared to placebo during all treatment weeks (P < 0.001). All treatments were well tolerated.

CONCLUSIONS

EqXL given once-daily was non-inferior to MPH-IR given twice-daily. Both treatments were superior to placebo in reducing ADHD symptoms.

Attention deficit hyperactivity disorder: an update

Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder, affecting 3% to 5% of school-aged children. Of the 3 subtypes--predominantly inattentive, predominantly hyperactive/impulsive, and a combined subtype--the latter is the most commonly represented group, accounting for 50% to 70% of all ADHD individuals. Stimulant medication is the cornerstone of management; however, stimulants with a short duration of action have been problematic for some patients. Recent technologic advances in delivery systems offer many patients the option of a once-daily dosage.