Comparative pharmacodynamics and plasma concentrations of d-threo-methylphenidate hydrochloride after single doses of d-threo-methylphenidate hydrochloride and d,l-threo-methylphenidate hydrochloride in a double-blind, placebo-controlled, crossover laboratory school study in children with attention-deficit/hyperactivity disorder

OBJECTIVE: Methylphenidate has four optical isomers due to two asymmetries (erythro-threo and dextro-levo). The initial commercial formulation eliminated the erythro isomer, but the dextro-levo asymmetry was racemic, with equal amounts of d and l-threo isomers (d,l-MPH). Previous work has suggested that the d-threo isomer methylphenidate (d-MPH) rather than the l-threo isomer (l-MPH) is responsible for the clinical effects in children with attention-deficit/hyperactivity disorder (ADHD). This study compared the efficacy of acute equimolar doses of d-MPH and dl-MPH in reducing ADHD symptoms over an 8-hour period in a laboratory school setting and investigated the relationship of efficacy to plasma levels of MPH. METHOD: Thirty-two children with ADHD enrolled in this double-blind, placebo-controlled, crossover study, and 31 completed the study. On seven separate occasions separated by at least 6 days, the children received a single morning dose of d-MPH (2.5, 5, or 10 mg), d,l-MPH (5, 10, or 20 mg), or placebo and then were observed in a laboratory classroom setting for 8 hours. At specified intervals, blinded observers rated behavior, and the children performed a computerized math test. The plasma levels of MPH were related to the response to study medication. The safety profiles of the two formulations were compared. RESULTS: For both formulations, the responses to both MPH preparations were dose related, the plasma concentrations of l-MPH were negligible and of d-MPH were indistinguishable, and clinical efficacy was highly correlated with plasma concentrations of d-MPH. The efficacy of the d-isomer was equivalent to the racemic preparation in reducing ADHD symptoms and increasing academic productivity. CONCLUSIONS: The efficacy of MPH resides in the d-isomer. The elimination of the l-isomer does not diminish the efficacy of an acute dose of methylphenidate.     

Pharmacokinetics of methylphenidate in preschoolers with attention-deficit/hyperactivity disorder

OBJECTIVE: The aim of this study was to compare the pharmacokinetics of immediate-release methylphenidate (MPH) in preschool and school-aged children with attention-deficit/hyperactivity disorder (ADHD). METHODS: Preschool children 4-5 years (n = 14) and school-aged children 6-8 years (n = 9) with diagnoses of ADHD were titrated to an effective dose of MPH based on parent, teacher, and clinician ratings in a protocol specified by the Preschoolers with ADHD Treatment Study (PATS) and then attended a laboratory school where the single morning dose of immediate release MPH was administered. Blood samples for measurement of MPH concentrations were obtained predose, and at 1, 2, 4, and 6 hours postdose. A nonlinear model was used to derive three pharmacokinetic (PK) values for analysis: Peak plasma concentration (C(max)), half-life (t(1/2)), and clearance (CL). RESULTS: The two groups did not differ in the mean mg dose of MPH (p = 0.33), or in the weight-adjusted mg/kg dose (p = 0.20). Dose-normalized C(max) was significantly higher (p = 0.003), and clearance was significantly slower (p = 0.0002) in preschool than in school-aged children. CONCLUSIONS: In this sample, age significantly affected absorption and metabolism of MPH, so that preschool children had greater exposure than school-aged children to the same weight-adjusted dose. These data suggest additional studies should be performed to characterize age-related differences in PK properties of MPH that may inform practitioners about dosing strategies based on the age and size of children being treated.     

Methylphenidate blood levels and therapeutic response in children with attention-deficit hyperactivity disorder: I. Effects of different dosing regimens

BACKGROUND AND PURPOSE: Methylphenidate (MPH) is a drug of choice for treating attention-deficit/hyperactivity disorder (ADHD), although its use has been complicated by its short duration of action. The development of ideal long-acting preparations requires detailed understanding of the pharmacokinetic and pharmacodynamic consequences of complex dosing regimens. The purpose of this study was to ascertain if administration paradigms that produce stable or rising MPH levels alter the rate with which MPH is absorbed, and to determine how effectively long-acting administration paradigms compare with thrice daily administration of immediate-release MPH. METHOD: Forty-eight boys diagnosed with ADHD (mean age 10.6 +/- 1.1 year) participated in this double-blind, parallel group study to evaluate the pharmacokinetics and efficacy and of 1 mg/kg/day MPH administered in five different paradigms and placebo. Objective measures of activity and attention (McLean Motion Attention Test; M-MAT) and plasma measures of d- and l-MPH were obtained hourly during the course of a 12-hour laboratory session. RESULTS: The rate of absorption and elimination of d-MPH was dependent on the pattern of administration, particularly on the initial bolus concentration. This suggests that d-MPH may act on the gastrointestinal system to slow absorption of additional d-MPH. There were significant differences among regimens on time course and degree of therapeutic response. Pulsatile administration produced greater improvement than escalating levels.     

A comprehensive in vitro screening of d-, l-, and dl-threo-methylphenidate: an exploratory study

dl-Methylphenidate (MPH) has been widely used to treat attention-deficit/hyperactivity disorder (ADHD) for the last half century. It had been exclusively available in the racemic form, i.e., a 50:50 mixture of d- and l-isomers. However, a single enantiomer formulation, d-MPH (dexmethylphenidate), became available for general clinical use in 2002. For this reason, the intrinsic pharmacological differences in the effects of d- and l-MPH have recently come under intense investigation. The primary therapeutic effects of MPH are generally recognized to reside in the d-isomer. The present investigation provides quantitative values for a broad range of receptor-level interactions of the individual MPH isomers to better characterize the distinction between dl-MPH versus d-MPH versus l-MPH as it relates to binding affinity at sites associated with relevant central nervous system (CNS) pharmacology, as well as peripheral physiology. Overall, there were few differences in binding affinities between d-MPH and the racemate whereas there were more apparent differences between d-MPH and l-MPH. d-MPH exhibited prominent affinity at the norepinephrine transporter (NET) site, even exceeding such affinity at the dopamine transporter (DAT). These results further demonstrate that affinity for catecholaminergic sites largely resides in the d-MPH isomer. Although binding affinity was not demonstrable at the serotonin (5-HT) transporter site (SERT), novel findings of the study included affinity for the 5-HT1A and 5-HT2B receptor sites for both d- and l-MPH, with d-MPH exerting by far the most predominant effects at these sites. Thus, the emerging data of favorable therapeutic effects of ADHD treatment with d-MPH (and dl-MPH) may be underpinned by affinity and potential pharmacologic effects at NET and DAT sites, as well as sites relevant to serotonergic neurotransmission that may modulate mood, cognition, and motor behavior. However, the present exploratory studies reflect receptor binding affinities only. The specific pharmacological activities (i.e., agonism vs. antagonism) of these compounds await further exploration.     

Open-label study of dexmethylphenidate hydrochloride in children and adolescents with attention deficit hyperactivity disorder

BACKGROUND: This pilot study examined the efficacy and duration of the effect of dexmethylphenidate (d-MPH) given once-daily in subjects with attention deficit hyperactivity disorder (ADHD). METHOD: Subjects aged 6-18 years (inclusive) with ADHD were enrolled in this 8-week, openlabel study. Outcome measures included the Conners'Teacher and Parent Rating Scales, the Attention Deficit Disorder Rating Scale (ADDRS), the Clinical Global Impression (CGI) Scale, and teacher and parent visual analog scales to estimate the duration of efficacy. d-MPH was initiated at a dose of 2.5 mg/day. The dose was flexible, based on response and tolerability, and could be increased in increments of 2.5 mg/day to a maximum daily dose of 30 mg/day. RESULTS: Twenty-two subjects (mean age, 8.7 +/- 0.4 years) were treated. Significant improvements (p <0.0001) from baseline occurred in the Conners' Teacher and Parent Rating Scales after 8 weeks. Of the evaluated subjects, 85.7% (18 of 21) showed at least a 30% improvement from baseline on the Conners' Teacher Rating Scale, and 86.4% (19 of 22) of subjects showed at least a 30% improvement from baseline on the Conners' Parent Rating Scale. Most subjects demonstrated an improvement on the ADDRS and the CGI-Improvement (CGI-I) scale. Median duration of effect was estimated at 6.2 hours (teachers) and at 7.5 hours (parents). On average, patients gained 2.4 pounds over the course of the study. CONCLUSIONS: A single daily dose of d-MPH was effective in controlling ADHD in children and was well tolerated. Future studies are needed to confirm these findings and to evaluate chronic dosing with d-MPH.     

Dexmethylphenidate extended-release capsules in children with attention-deficit/hyperactivity disorder

OBJECTIVE: This study compared once-daily dexmethylphenidate extended release (D-MPH-ER) 20 mg/day and placebo over 12 hours in children ages 6 to 12 with attention-deficit/hyperactivity disorder (ADHD) in a laboratory classroom setting. METHOD: All of the children were stabilized for > or =2 weeks on a total dose (nearest equivalent) MPH 40 mg/day or immediate-release D-MPH 20 mg/day before screening. After a practice day, they received 6 days of D-MPH-ER 20 mg/day or placebo at home, returning on day 7 for one dose. Subjects were evaluated at predose and postdose hours 0.5, 1, 3, 4, 5, 7, 9, 10, 11, and 12 and then crossed over to the other treatment arm using the identical protocol. The primary efficacy variable was the change from predose in Swanson, Kotkin, Agler, M-Flynn, and Pelham rating scale (SKAMP) combined score from 1 to 12 hours. Secondary efficacy variables included SKAMP combined score at 0.5 hours, SKAMP subscale scores, and math test results over 12 hours. RESULTS: Sixty-eight children were randomized, with 67 completing the study. Onset of action was indicated by a significant difference between D-MPH-ER and placebo at 0.5 hour on the SKAMP combined score (p = .001). For efficacy measures, differences from placebo were significant at all points between 0.5 and 12 hours (p < .001 top = .013). CONCLUSIONS: D-MPH-ER provided sustained improvement in attention, deportment, and academic productivity throughout the 12-hour laboratory day.     

Efficacy of two long-acting methylphenidate formulations in children with attention- deficit/hyperactivity disorder in a laboratory classroom setting

OBJECTIVE: The aim of this study was to compare efficacy and safety of two long-acting formulations of methylphenidate (MPH) for attention-deficit/hyperactivity disorder (ADHD) in school-age children. METHODS: Children 6-12 years of age diagnosed with ADHD and stabilized on MPH (20-40 mg/day) participated in a five-way, randomized, placebo-controlled, single-blind, crossover study conducted in a laboratory classroom setting. Children alternately received single doses of extended-release MPH (ER-MPH) 20 and 40 mg, modified-release MPH (OROS-MPH) 18 and 36 mg, and placebo over 6 consecutive weeks. Efficacy was assessed using SKAMP rating subscales and written math tests. Data were examined using between-treatment comparisons of area under the curve (AUC) for change from predose values during hours 0-4, 0-8, 8-12, and 0-12. Safety was assessed. RESULTS: Fifty-three children completed the study. For all efficacy measures, improvements from predose were significantly greater with ER-MPH 40 mg than with OROS-MPH 36 mg in terms of AUC(0-4) (p < or = 0.005), AUC(0-8) (p < or = 0.006), and AUC(0-12) (p < or = 0.035). For most measures, ER-MPH 20 mg was equivalent to both doses of OROS-MPH in AUC(0-4), AUC(0-8), and AUC(0-12). No serious adverse events were reported. CONCLUSIONS: The efficacy of ER-MPH 20 mg is similar to that of OROS-MPH 18 and 36 mg during the first 8 hours postdose. Statistically greater benefits are observed with ER-MPH 40 mg than with OROS-MPH 36 mg and persist through hour 8. Active treatments show comparable efficacy from 8 to 12 hours postdose. Both doses of each MPH formulation are well tolerated.     

Effects of methylphenidate, desipramine, and L-dopa on attention and inhibition in children with Attention Deficit Hyperactivity Disorder

The objective of this study was to investigate the effects of methylphenidate (MPH) on attention and inhibition in children with Attention Deficit Hyperactivity Disorder (ADHD) and to establish what the relative contributions of the noradrenergic and dopaminergic systems to this effect were. In addition to MPH, two other drugs were administered in order to affect both transmitter systems more selectively, L-dopa (dopamine (DA) agonist) and desipramine (DMI) (noradrenaline (NA) re-uptake inhibitor). Sixteen children with ADHD performed a stop-task, a laboratory task that measures the ability to inhibit an ongoing action, in a double-blind randomized within-subjects design. Each child received an acute clinical dose of MPH, DMI, L-dopa, and placebo; measures of performance and plasma were determined. The results indicated that inhibition performance was improved under DMI but not under MPH or L-dopa. The response-time to the stop-signal was marginally shortened after intake of DMI. MPH decreased omission and choice-errors and caused faster reaction times to the trials without the stop-tone. No effects of L-dopa whatsoever were noted. Prolactin levels were increased and 5-HIAA levels were lowered under DMI relative to placebo. It is suggested that the effects of MPH on attention are due to a combination of noradrenergic and dopaminergic mechanisms. The improved inhibition under DMI could be serotonergically mediated.     

Dopamine transporter gene,response to methylphenidate and cerebral blood flow in attention-deficit/hyperactivity disorder: a pilot study

The homozygosity of the 10-repeat allele at dopamine transporter gene (DAT1) seems to be associated with a poor response to methylphenidate (MPH) in children with attention-deficit/hyperactivity disorder (ADHD). This pilot study aimed to simultaneously assess polymorphisms at DAT1, response to MPH, and neuroimaging. Only ADHD children with at least a moderate response to MPH were included. Significantly higher regional cerebral blood flows assessed by single photon emission computerized tomography (SPECT) were detected in medial frontal and left basal ganglia areas in children with homozygosity for the 10-repeat allele at DAT1 gene (n = 4) than in children without this genotype (n = 4) (P < 0.05). These findings provide a preliminary connection between pharmacogenetics and neurobiological investigations on stimulant treatment of ADHD.     

A double-blind, placebo-controlled withdrawal trial of dexmethylphenidate hydrochloride in children with attention deficit hyperactivity disorder

OBJECTIVES: d,l-threo-methylphenidate HCl (D,L-MPH) is the most common treatment of attention deficit hyperactivity disorder (ADHD). A previous report showed placebo-controlled efficacy for the purified d-isomer (dexmethylphenidate hydrochloride, d-MPH, Focalin) with a 2:1 potency compared to dl, and suggested a 6-hour duration of action. This study complements that report by studying the effect of placebo-controlled discontinuation and retesting the duration of action. METHODS: A 6-week, open-label titration of d-MPH (2.5-10 mg twice-a-day) was followed by a double-blind, placebo-controlled, 2-week withdrawal study of responders. RESULTS: In the open titration, 82% of the 89 enrolled patients achieved a Clinical Global Impression-Improvement (CGI-I) rating of much or very much improved. Only 5 patients discontinued for adverse events. Seventy-five patients continued into the placebo-controlled discontinuation. For the randomly assigned d-MPH (n=35) and placebo (n=40) groups, mean ages, respectively, were 10.1 +/- 2.9 and 9.9 +/- 2.7 years, 86% and 78% were male, and 70.6% and 80.0% took the ceiling dose of 10 mg twice-daily, respectively. Each group had 80% combined type ADHD and 20% inattentive type. By the end of the 2-week, placebo-masked withdrawal, significantly more placebo patients (24 of 39) than d-MPH continuers (6 of 35) relapsed (61.5% versus 17.1%, p=0.001). Compared to d-MPH continuers, placebo patients deteriorated significantly more in the 2-week period on teacher ratings of the 18 ADHD symptoms rated 0-3 (p=0.028), the 3 p.m. and 6 p.m. parent ADHD symptom ratings (p=0.0026 and p=0.0381, respectively), and clinic (2-3 p.m.) and home (6 p.m.) Math Tests (p=0.024 and p<0.0001, respectively). The 6 p.m. scores replicated the significant effect at 6 hours reported in the previous study. CONCLUSIONS: d-MPH is safe, tolerable, and effective, with a 6-hour duration of effect suggested by the significant difference from placebo at 6 hours on a double-blind discontinuation.     

Autonomic hypoactivity in boys with attention-deficit/hyperactivity disorder and the influence of methylphenidate

Objectives. This study investigates an overall autonomic hypoactivity reflecting hypoarousal as important aetiological factor in ADHD at baseline during rest and in response towards stimuli. In addition, effects of methylphenidate (MPH) are examined. We further assessed whether this hypoarousal is a stable characteristic or ameliorated by arousing emotional stimuli. Methods. Boys with ADHD were examined with (n = 35) or without MPH (n = 45) and compared with healthy boys (n = 22) regarding skin conductance level (SCL) during rest and skin conductance responses (SCRs) as well as valence and arousal ratings in response to positive, neutral, and negative pictures. Results. ADHD children without MPH were characterized by reduced baseline SCL and overall reduced SCRs. ADHD children with MPH never differed from control children. All groups displayed normal valence and arousal ratings of the stimuli and enhanced SCRs to emotional in comparison to neutral pictures. Conclusions. This is the first study to unravel (1) a general autonomic hypoactivity in ADHD children at baseline and in response to low arousing neutral and highly arousing emotional stimuli, and (2) hints that MPH normalizes this hypoactivity. Results contribute to the understanding of ADHD aetiology and MPH functionality, and are consistent with the cognitive-energetic model of ADHD.     

Acute effects of methylphenidate on performance during the Test of Variables of Attention in children with attention deficit/hyperactivity disorder

This study attempted to determine the acute effects of methylphenidate (MPH) on cognitive performance using the Test of Variables of Attention (TOVA) in children with attention deficit/hyperactivity disorder (ADHD). The study subjects comprised 57 children diagnosed with ADHD aged 6-13 years. Diagnoses of ADHD and other comorbid psychiatric disorders were based on Diagnostic and Statistical Manual of Mental Disorders-fourth edition criteria following a standard interview with the Schedule for Affective Disorder and Schizophrenia for School-Age Children, epidemiologic version. The subjects' performance on the TOVA was compared before and 1 h after administration of MPH. After administration of MPH, commission scores, response time and ADHD scores improved significantly, however, there were no significant changes in omission scores, response time variability or response sensitivity. The authors concluded that administration of one dose of MPH (0.5-1.0 mg/kg) produced more effects on impulsivity than on attention deficiency in children with ADHD, and that the second half section of the TOVA could be more sensitive than the first half in determining the acute effects of MPH therapy in children with ADHD. However, the effects of different MPH doses on the TOVA results need further investigation.     

Methylphenidate improves prefrontal cortical cognitive function through α2 adrenoceptor and dopamine D1 receptor actions: Relevance to therapeutic effects in Attention Deficit Hyperactivity Disorder

Background  

Methylphenidate (MPH) is the classic treatment for Attention Deficit Hyperactivity Disorder (ADHD), yet the mechanisms underlying its therapeutic actions remain unclear. Recent studies have identified an oral, MPH dose regimen which when given to rats produces drug plasma levels similar to those measured in humans. The current study examined the effects of these low, orally-administered doses of MPH in rats performing a delayed alternation task dependent on prefrontal cortex (PFC), a brain region that is dysfunctional in ADHD, and is highly sensitive to levels of catecholamines. The receptor mechanisms underlying the enhancing effects of MPH were explored by challenging the MPH response with the noradrenergic α2 adrenoceptor antagonist, idazoxan, and the dopamine D1 antagonist, SCH23390.     

Response to methylphenidate in children with ADHD and comorbid anxiety

OBJECTIVE: To determine whether comorbid anxiety alters response to methylphenidate (MPH) in children with attention-deficit hyperactivity disorder (ADHD). METHOD: Ninety-one children with ADHD were assessed for anxiety. Children were randomly assigned to receive MPH or placebo, titrated to a dose of 0.7 mg/kg, while side effects were minimized. Measures of side effects and behavioral response were obtained from parents and teachers before treatment, after titration to optimal dose, and after 4 months of treatment. These measures, dose of drug, and rate of adherence to assigned medication assignment were compared for nonanxious (ADHD- ANX) and anxious ADHD children (ADHD+ ANX). RESULTS: Rates of adherence to original medication assignment did not differ between the groups. ADHD+ ANX on both MPH and placebo titrated to a lower dose at the end of titration, although the dose of drug did not differ among the groups after 4 months of treatment. No differential response to MPH between ADHD+ ANX and ADHD- ANX was noted at end-titration or at 4 months on any side effect or behavioral measures. CONCLUSIONS: Comorbid anxiety does not appear to influence development of side effects or behavioral response to MPH when dose is titrated as in standard clinical practice.     

Boys with attention-deficit/hyperactivity disorder perform wider and fewer finger tapping than typically developing boys – Peer comparisons and the effects of methylphenidate from an exploratory perspective

AimThis study aimed to investigate the differences in fine motor and coordination skills between boys with attention-deficit/hyperactivity disorder (ADHD) and typically developing (TD) boys and the effect of methylphenidate (MPH) in boys with ADHD.MethodsFourteen boys aged 7–12 years who were diagnosed with ADHD and previously treated with MPH were instructed to tap their thumbs and index fingers together repetitively for 10 s after attaching magnetic sensors. The participants executed “in-phase” and “anti-phase” tapping. A two-way analysis of variance for comparing boys with ADHD and TD boys and the paired t-test to investigate the effect of MPH between sessions with and without MPH were performed.ResultsBoys with ADHD showed a significantly lower “number of taps” and a significantly higher “average of local maximum distance” than TD boys. “Energy balance” was significantly lower in ADHD boys than in TD boys. MPH caused a significant difference in the “standard deviation (SD) of phase difference” in “anti-phase tapping.”ConclusionOur studies indicated that finger-tapping movements in boys with ADHD tended to be significantly wider and fewer than those in TD boys, and MPH may improve the phase difference of bimanual fine motor coordination skills in boys with ADHD who are above 1.0 SD. The results should be interpreted with caution because we conducted statistical tests for many outcomes and groups without considering the multiplicity factor from an exploratory perspective.     

Novel strategy for the analysis of CPT data provides new insight into the effects of methylphenidate on attentional states in children with ADHD

Continuous performance tasks (CPTs) provide a method for studying some components of attention, but do not take into account that attention fluctuates from moment to moment. To address this issue, CPT performance was classified into one of four states (on-task, impulsive, distracted, or randomly responding) every 30 seconds, based on commission and omission error rates. We evaluated this method on 60 boys (10.6 +/- 1.1 years) with attention-deficit hyperactivity disorder (ADHD)-Combined subtype, tested before and after a dose of methylphenidate (MPH, 0.4 mg/kg), and 8 unmedicated healthy control boys (11.3 +/- 2.0 years of age). Healthy controls were on-task during 82.4% of the 30-second epochs, and made an average of 5.4 attention shifts. In contrast, children with ADHD were only on-task during 42.6% of the epochs (p = 0.0006), and they made an average of 12.8 attention shifts (p = 0.00004). These state measures provided more robust indicators of the difference between children with ADHD and controls than did traditional CPT measures of error rates, latency, and variability. The new state measures were also more significantly affected by MPH. MPH produced a 77% increase in the percent of time children with ADHD spent on-task (p < 10(12)). Conversely, MPH reduced time spent in the distracted, impulsive, and random response states by 79%, 44.5%, and 69.2%, respectively (all p values < 0.0002). Unlike errors of omission and commission, which are highly correlated (r = 0.722, n = 60, p < 10(-11)), the percent of epochs spent in impulsive, distracted, and random response states were uncorrelated, and loaded onto discrete independent factors on principal component analysis. The level of activity during the CPT correlated with the degree of distraction, but not with the degree of impulsivity. Children with ADHD could be subtyped according to the nature of their attention performance problems, and these subtypes differed in levels of hyperactivity and degrees of response to MPH.     

A large, double-blind, randomized clinical trial of methylphenidate in the treatment of adults with attention-deficit/hyperactivity disorder.

BACKGROUND: The few controlled studies of methylphenidate (MPH) in adults with attention deficit/hyperactivity disorder (ADHD) have reported equivocal results. A previous, pilot study by our group suggested that these results were due to inadequate dosing. METHOD: We conducted a randomized, 6-week, placebo-controlled, parallel study of MPH in 146 adult patients with DSM-IV ADHD using standardized instruments for diagnosis, separate assessments of ADHD, depressive and anxiety symptoms, and a robust average oral daily dose of 1.1 mg/kg/day. RESULTS: We found a marked therapeutic response for the MPH treatment of ADHD symptoms that exceeded the placebo response (76% vs. 19%). Treatment was safe and well tolerated. Response to MPH was independent of socioeconomic status, gender, and lifetime history of psychiatric comorbidity. CONCLUSIONS: These results confirm that robust doses of MPH are effective in the treatment of adult ADHD.     

A preliminary study on the effect of methylphenidate on motor performance in children with comorbid DCD and ADHD

Attention Deficit Hyperactive Disorder (ADHD) and Developmental Coordination Disorder (DCD) are two developmental disorders with considerable comorbidity. The impact of Methylphenidate (MPH) on ADHD symptoms is well documented. However, the effects of MPH on motor coordination are less studied. We assessed the influence of MPH on motor performance of children with comorbid DCD and ADHD. Participants were 18 children (13 boys, mean age 8.3 years) diagnosed with comorbid DCD and ADHD. A structured clinical interview (K-SADS-PL) was used to determine psychopathology and the Movement Assessment Battery for Children–Checklist were used to determine criterion for motor deficits. The Movement Assessment Battery for Children (M-ABC) was administrated to all participants once under the influence of MPH and once under a placebo pill condition. The motor tests were administered on two separate days in a double-blinded design. Participants’ motor performance with MPH was significantly superior to their performance in the placebo condition. Significant improvement was observed in all the M-ABC sub-tasks except for static balance performance. The findings suggest that MPH improves motor coordination in children with comorbid DCD and ADHD but clinically significant improvement was found in only 33% of the children.     

12-month efficacy and safety of OROS® MPH in children and adolescents with attention-deficit/hyperactivity disorder switched from MPH

PURPOSE: The aim of this study was to evaluate long-term clinical treatment with OROS methylphenidate (MPH) (Concerta) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) who had been previously treated with immediate release (IR) MPH. METHODS: Subjects aged 6-16 years (n=105) who were stable on IR MPH (10-60 mg/day) were switched to 18, 36 or 54 mg OROS MPH once daily for 21 days, depending on prestudy MPH dose. Subjects who benefited from OROS MPH could continue in a 12-month extension period. ADHD symptoms and treatment response were assessed by parents/caregivers and investigators. RESULTS: Out of 105 enrolled children, 101 completed the 21-day treatment phase. In all, 89 parents/caregivers (88.1%) wanted their child to continue with the study treatment into the extension phase, and 56 children (63 %) completed the 1-year trial. The parent/caregiver global assessment of satisfaction ranged from 49 to 69% during the extension phase, and 49 to 71% of investigators rated the treatment as adequate. Efficacy and satisfaction were found more commonly in patients in the older age group (10-16 years), those on a higher dose (36 mg or 54 mg) and with the predominantly inattentive ADHD subtype. OROS MPH was well tolerated. CONCLUSIONS: Children and adolescents can effectively and safely be switched from IR MPH to OROS MPH with improved symptom control and compliance.