Switching from oral extended-release methylphenidate to the methylphenidate transdermal system: continued attention-deficit/hyperactivity disorder symptom control and tolerability after abrupt conversion

Systematic review of transdermal treatment options in attention-deficit/hyperactivity disorder: implications for use in adult patients

BACKGROUND

Adults with attention-deficit/hyperactivity disorder (ADHD) often face delays in diagnosis and remain untreated, despite significant negative impacts. To evaluate the safety and efficacy of transdermal treatment options in children, adolescents, and adults, a systematic literature review was conducted, with a focus on the implications of transdermal therapies for ADHD in adults.

METHODS

A MEDLINE/Embase/BIOSIS/SCOPUS database search was conducted December 4, 2019, for English-language articles of interventional clinical trials using transdermal formulations for the treatment of ADHD without publication date limit. Assessed outcomes included efficacy, safety, adherence, abuse potential, cost efficacy, and health-related quality of life.

RESULTS

Of 23 eligible publications, 18 were in children or adolescents (n = 1699; range 23-305), and 5 in adults (n = 274; range 14-90); all included methylphenidate transdermal system (MTS). All seven pediatric publications reporting change in ADHD symptomology from baseline reported a significant improvement with MTS treatment. Similarly, in three adult publications, ADHD symptoms improved significantly with MTS treatment. Safety findings in pediatric and adult studies were comparable; the most frequently reported treatment-emergent adverse events (TEAEs), namely, headache, decreased appetite, and insomnia, were reported in 13/16 (81%) of publications reporting specific TEAEs. MTS-related dermal reactions were mostly mild and transient. Discontinuation due to dermal reactions was reported in 10 studies (range 0%-7.1% [1 of 14 patients]). MTS compliance was high when assessed (97%-99%).

CONCLUSIONS

Transdermal therapies provide a useful treatment formulation for ADHD. Studies of MTS and other transdermal formulations, such as amphetamine, in adult patients are needed in this underserved population.

Evaluation of Methylphenidate Safety and Maximum-Dose Titration Rationale in Attention-Deficit/Hyperactivity Disorder: A Meta-analysis

IMPORTANCE

Evidence on the titration of stimulant medications for attention-deficit/hyperactivity disorder (ADHD) is lacking. However, this lack of evidence has not prevented medication guidelines from specifying apparently arbitrary dose limitations, which could discourage clinicians from titrating methylphenidate to higher and, perhaps for some patients, more efficacious doses.

OBJECTIVE

To determine the evidence on dose titration and adverse events associated with dose titration of stimulants for ADHD.

DATA SOURCES

MEDLINE from 1946, Embase from 1974, and PsycINFO from 1806 through April 1, 2019, were searched to identify relevant articles.

STUDY SELECTION

The inclusion criteria were that (1) the study was conducted on children up to 18 years of age; (2) children had a diagnosis of ADHD according to the Diagnostic and Statistical Manual of Mental Disorders, or hyperkinetic disorder according to the International Classification of Diseases codes; and (3) the dose of methylphenidate was determined by titration.

DATA EXTRACTION AND SYNTHESIS

The PRISMA guidelines for abstracting data and assessing data quality and validity were followed. Quality assessment was undertaken using the Jadad scoring system. Statistical analysis was undertaken using a random-effects model.

MAIN OUTCOMES AND MEASURES

The outcomes of interest were (1) the doses used in published clinical trials, (2) the clinical justification given by researchers for their selected dose range, and (3) the adverse effects associated with methylphenidate when the dose is established by titration.

RESULTS

A total of 11 randomized clinical trials and 38 cohort studies were analyzed. The randomized clinical trials involved 1304 participants treated with methylphenidate and 887 controls; the 38 cohort studies included 5524 participants. Maximum doses of methylphenidate ranged from 0.8 to 1.8 mg/kg/d. Some studies detailed their method of titration, including starting dose, titration interval, increment dose, and maximum dose. Not all of these studies reported justification for the chosen dose range. Common adverse effects of methylphenidate included insomnia (odds ratio, 4.66; 95% CI, 1.99-10.92; P < .001), anorexia (5.11 higher than for those who took placebo; 95% CI, 1.99-13.14; P < .001), abdominal pain (1.9 times more likely; 95% CI, 0.77-4.77; P = .16), and headache (14% of participants; 95% CI, 10%-20%; P < .001).

CONCLUSIONS AND RELEVANCE

A range of maximum doses for methylphenidate was recommended in clinical studies; no discernable scientific justification for any particular dose was given. Reports of life-threatening adverse events were absent; further studies of the efficacy, tolerability, and safety of methylphenidate titrated purely on clinical grounds, without reference to any set maximum dose, are needed.

New Formulations of Stimulants: An Update for Clinicians

In the last 15 years, there has been a marked increase in the number of available stimulant formulations with the emphasis on long-acting formulations, and the introduction of several novel delivery systems such as orally dissolving tablets, chewable tablets, extended-release liquid formulations, transdermal patches, and novel "beaded" technology. All of these formulations involve changes to the pharmaceutical delivery systems of the two existing compounds most commonly employed to treat attention-deficit/hyperactivity disorder (ADHD), amphetamine (AMP) and methylphenidate (MPH). In addition to these new formulations, our knowledge about the individual differences in response has advanced and contributes to a more nuanced approach to treatment. The clinician can now make increasingly informed choices about these formulations and more effectively individualize treatment in a way that had not been possible before. In the absence of reliable biomarkers that can predict individualized response to ADHD treatment, clinical knowledge about differences in MPH and AMP pharmacodynamics, pharmacokinetics, and metabolism can be utilized to personalize treatment and optimize response. Different properties of these new formulations (delivery modality, onset of action, duration of response, safety, and tolerability) will most likely weigh heavily into the clinician's choice of formulation. To manage the broad range of options that are now available, clinicians should familiarize themselves in each of these categories for both stimulant compounds. This review is meant to serve as an update and a guide to newer stimulant formulations and includes a brief review of ADHD and stimulant properties.

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.

Transdermal therapy for attention-deficit hyperactivity disorder with the methylphenidate patch (MTS)

Transdermal technology is currently approved in the US for the administration of more than 20 medications. This current review describes the clinical research pertaining to the use of a methylphenidate patch in the treatment of attention-deficit hyperactivity disorder (ADHD) in children and adolescents. PubMed searches were conducted using the search term 'methylphenidate transdermal system', and were limited to clinical trials. No limits were set for dates of publication. A total of 21 citations were identified. Studies evaluating the safety and efficacy of the methylphenidate transdermal system (MTS) in children and adolescents were included in this review. Additional studies were identified from bibliographies and the 'Related Citations' section of PubMed searches. The MTS delivers a range of methylphenidate doses using a drug-in-adhesive matrix patch. According to current labeling, the patch should be applied to the hip once daily for a maximum of 9 h. Serum methylphenidate levels increase over wear time, with mean time to maximum concentration (t max) reached between 8 and 10 h for a 9-h wear time, and the elimination half-life for methylphenidate is 3-4 h after patch removal. In clinical trials, ADHD symptoms were measured using the ADHD Rating Scale, Version IV, and several parent-, teacher-, and patient-rated scales. Treatment effects show statistically significant differences from baseline symptom scores starting at the first evaluation, 2 h after the patch is applied, with significant benefit lasting up to 12 h with a 9-h wear time. Adverse events with the MTS are similar to those seen with other formulations of methylphenidate, with the exception of skin-related reactions at the site of application, which were generally mild to moderate in severity. The incidence of contact allergic dermatitis with MTS is <1%. Statistically significant improvements in health-related quality of life and medication satisfaction were also observed with the MTS compared with placebo, and after switching from oral extended-release (ER) methylphenidate. Transdermal drug delivery is an effective and safe means of administering methylphenidate for patients with ADHD.

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.

Estimation of utilities in attention-deficit hyperactivity disorder for economic evaluations

BACKGROUND

Attempts to estimate the cost effectiveness of attention-deficit hyperactivity disorder (ADHD) treatments in the past have relied on classifying ADHD patients as responders or non-responders to treatment. Responder status has been associated with a small gain in health-related quality of life (HR-QOL) [or utility, as measured using the generic QOL measure EQ-5D] of 0.06 (on a scale from 0 being dead to 1.0 being full health).

OBJECTIVES

The goal of the present study was to develop and validate several ADHD-related health states, and to estimate utility values measured amongst the general public for those states and to re-estimate utility values associated with responder status.

METHODS

Detailed qualitative interview data were collected from 20 young ADHD patients to characterize their HR-QOL. In addition, item-by-item clinical and HR-QOL data from a clinical trial were used to define and describe four health states (normal; borderline to mildly ill; moderately to markedly ill; and severely ill). ADHD experts assessed the content validity of the descriptions. The states were rated by 100 members of the UK general public using the time trade-off (TTO) interview and visual analog scale. Statistical mapping was also undertaken to estimate Clinical Global Impression-Improvement (CGI-I) utilities (i.e. response status) from Clinical Global Impression-Severity (CGI-S) defined states. The mapping work estimated changes in utilities from study baseline to last visit for patients with a CGI-I score of ≤ 2 or ≤ 3.

RESULTS

The validity of the four health states developed in this study was supported by in-depth interviews with ADHD experts and patients, and clinical trial data. TTO-derived utilities for the four health states ranged from 0.839 (CGI-S state 'normal') to 0.444 (CGI-S state 'severely ill'). From the mapping work, the change in utility for treatment responders was 0.19 for patients with a CGI-I score of ≤ 2 and 0.15 for patients with a CGI-I score of ≤ 3.

CONCLUSIONS

The present study provides utilities for different severity levels of ADHD estimated in a TTO study. This approach provides a more granular assessment of the impact of ADHD on HR-QOL than binary approaches employed in previous economic analyses. Change in utility for responders and non-responders at different levels of CGI-I was estimated, and thus these utilities may be used to compare health gains of different ADHD interventions.

Methylphenidate transdermal system: a multisite, open-label study of dermal reactions in pediatric patients diagnosed with ADHD

OBJECTIVE

To characterize dermal reactions and examine methylphenidate (MPH) sensitization in subjects receiving methylphenidate transdermal system (MTS).

METHOD

This multicenter, open-label, dose-optimization study utilized MTS doses of 10, 15, 20, and 30 mg in children aged 6 to 12 years, inclusive (N = 305), with a DSM-IV-TR primary diagnosis of attention-deficit/hyperactivity disorder. The study was conducted between January 8, 2007, and August 23, 2007. Subjects wore MTS on their hips for 9 hours per day, alternating sides daily for a total of 7 weeks. Assessments included the Experience of Discomfort scale, Transdermal System Adherence scale, and Dermal Response Scale (DRS; 0 = no irritation, 7 = strong reaction). On-study reevaluations were conducted to characterize DRS scores ≥ 4. Epicutaneous allergy patch testing was conducted for DRS scores ≥ 6, persistent DRS scores ≥ 4, DRS score increase following an assessment of ≥ 4, or DRS scores of 4 or 5 following elective discontinuation.

RESULTS

Approximately half of subjects experienced definite erythema at the patch site that generally dissipated within 24 hours. Four subjects experienced a DRS score of 4 (1%): erythema in 1 subject resolved on study treatment, 2 cases resolved poststudy and subjects tolerated oral MPH, and 1 subject discontinued treatment. The latter subject was referred for patch testing and was diagnosed with allergic contact sensitization to MPH.

CONCLUSIONS

Few severe dermal effects were seen with MTS treatment. Dermal reactions were characterized as contact dermatitis and dissipated rapidly. On patch testing, 1 subject (0.3%) manifested sensitization to MPH.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00434213.

An observational study of once-daily modified-release methylphenidate in ADHD: the effect of previous treatment on ADHD symptoms, other externalising symptoms and quality-of-life outcomes

Methylphenidate (MPH) is the most commonly prescribed stimulant for children with ADHD. Data on the effects of different MPH formulations in real-life settings are scarce, and the role of previous therapy on treatment outcome when switching medications has not been well studied. OBSEER was an observational study designed to evaluate the effectiveness and safety of Equasym XL(®) in routine care. This study assessed whether the improvements reported with Equasym XL(®) are influenced by the degree of symptom control achieved with the previous medication. Patients enrolled in OBSEER were stratified by prior treatment (none, MPH-immediate release [IR] once daily [o.d.] [MPH-IR o.d.], MPH-IR repeated [MPH-IR >o.d.] and MPH-MR [modified release] excluding Equasym XL(®)), and changes in ADHD and other externalising symptoms (CGI-S, FBB-ADHD and DAYAS) and quality of life (QoL, KINDL) were evaluated during treatment with Equasym XL(®). A total of 782 patients were analysed. Significant group-by-time interactions were found for all symptom variables analysed, indicating that effects varied by previous medication. For CGI-S and FBB-ADHD total scores, the greatest reductions in ADHD symptoms were observed in the treatment-naïve subgroup, followed (in order) by MPH-IR o.d., MPH-IR >o.d. and MPH-MR. A similar profile was seen for DAYAS ratings for all periods of the day except the evening, when there were no significant differences between subgroups. Similarly, the treatment-naïve and MPH-IR o.d. subgroups showed the greatest improvements in KINDL ratings. Although effects were greatest for treatment-naïve patients, improvements were also observed in the prior treatment subgroups for symptoms and QoL. This suggests that a change to Equasym XL(®) may be beneficial in patients with suboptimal effects on prior medication.