Long-acting stimulants for treatment of attention-deficit/hyperactivity disorder: a focus on extended-release formulations and the prodrug lisdexamfetamine dimesylate to address continuing clinical challenges

Pharmacotherapy for ADHD in children and adolescents: A summary and overview of different European guidelines

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by a persistent pattern of inattention, hyperactivity, and impulsivity. It is the most common neurodevelopmental disorder presenting to pediatric services, and pediatricians are often involved in the early assessment, diagnosis, and treatment of children with ADHD. The treatment of ADHD typically involves a multimodal approach that encompasses a combination of psychoeducation, parent/teacher training, psychosocial/psychotherapeutic interventions, and pharmacotherapy. Concerning pharmacotherapy, guidelines vary in drug choice and sequencing, with psychostimulants, such as methylphenidate and (lis)dexamfetamine, generally being the favored initial treatment. Alternatives include atomoxetine and guanfacine. Pharmacotherapy has been proven effective, but close follow-up focusing on physical growth, cardiovascular monitoring, and the surveillance of potential side effects including tics, mood fluctuations, and psychotic symptoms, is essential. This paper presents an overview of current pharmacological treatment options for ADHD and explores disparities in treatment guidelines across different European countries.   Conclusion: Pharmacological treatment options for ADHD in children and adolescents are effective and generally well-tolerated. Pharmacotherapy for ADHD is always part of a multimodal approach. While there is a considerable consensus among European guidelines on pharmacotherapy for ADHD, notable differences exist, particularly concerning the selection and sequencing of various medications. What is Known: • There is a significant base of evidence for pharmacological treatment for ADHD in children and adolescents. • Pediatricians are often involved in assessment, diagnosis and management of children with ADHD. What is New: • Our overview of different European guidelines reveals significant agreement in the context of pharmacotherapy for ADHD in children and adolescents. • Discrepancies exist primarily in terms of selection and sequencing of different medications.

Treatment Outcomes With Licensed and Unlicensed Stimulant Doses for Adults With Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis

Importance

Stimulants (methylphenidate and amphetamines) are often prescribed at unlicensed doses for adults with attention-deficit/hyperactivity disorder (ADHD). Whether dose escalation beyond US Food and Drug Administration recommendations is associated with positive risk benefits is unclear.

Objective

To investigate the impact, based on averages, of stimulant doses on treatment outcomes in adults with ADHD and to determine, based on averages, whether unlicensed doses are associated with positive risk benefits compared with licensed doses.

Data Sources

Twelve databases, including published (PubMed, Cochrane Library, Embase, Web of Sciences) and unpublished (ClinicalTrials.gov) literature, up to February 22, 2023, without language restrictions.

Study Selection

Two researchers independently screened records to identify double-blinded randomized clinical trials of stimulants against placebo in adults (18 years and older) with ADHD.

Data Extraction and Synthesis

Aggregate data were extracted and synthesized in random-effects dose-response meta-analyses and network meta-analyses.

Main Outcome Measures

Change in ADHD symptoms and discontinuations due to adverse events.

Results

A total of 47 randomized clinical trials (7714 participants; mean age, 35 (SD, 11) years; 4204 male [56%]) were included. For methylphenidate, dose-response curves indicated additional reductions of symptoms with increments in doses, but the gains were progressively smaller and accompanied by continued additional risk of adverse events dropouts. Network meta-analyses showed that unlicensed doses were associated with greater reductions of symptoms compared with licensed doses (standardized mean difference [SMD], -0.23; 95% CI, -0.44 to -0.02; very low certainty of evidence), but the additional gain was small and accompanied by increased risk of adverse event dropouts (odds ratio, 2.02; 95% CI, 1.19-3.43; moderate certainty of evidence). For amphetamines, the dose-response curve approached a plateau and increments in doses did not indicate additional reductions of symptoms, but there were continued increments in the risk of adverse event dropouts. Network meta-analysis did not identify differences between unlicensed and licensed doses for reductions of symptoms (SMD, -0.08; 95% CI, -0.24 to 0.08; very low certainty of evidence).

Conclusions and Relevance

Based on group averages, unlicensed doses of stimulants may not have positive risk benefits compared with licensed doses for adults with ADHD. In general, practitioners should consider unlicensed doses cautiously. Practitioners may trial unlicensed doses if needed and tolerated but should be aware that there may not be large gains in the response to the medication with those further increments in dose. However, the findings are averages and will not generalize to every patient.

Evidence-based pharmacological treatment options for ADHD in children and adolescents

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity, causing functional impairment. Its prevalence lies at approximately 5% in children and adolescents and at approximately 2.5% in adults. The disorder follows a multifactorial etiology and shows a high heritability. Patients show a high interindividual and intraindividual variability of symptoms, with executive deficits in several cognitive domains. Overall, ADHD is associated with high rates of psychiatric comorbidities, and insufficient treatment is linked to adverse long-term outcomes. Current clinical guidelines recommend an individualized multimodal treatment approach including psychoeducation, pharmacological interventions, and non-pharmacological interventions. Available medications include stimulants (methylphenidate, amphetamines) and non-stimulants (atomoxetine, guanfacine, clonidine). While available pharmacological treatment options for ADHD show relatively large effect sizes (in short-term trials) and overall good tolerability, there is still a need for improvement of current pharmacotherapeutic strategies and for the development of novel medications. This review summarizes available pharmacological treatment options for ADHD in children and adolescents, identifies current issues in research and evidence gaps, and provides an overview of ongoing efforts to develop new medications for the treatment of ADHD in children and adolescents by means of a systematic cross-sectional analysis of the clinical trials registry www.clinicaltrials.gov.

Adult Patient Preferences for Long-Acting ADHD Treatments: A Discrete Choice Experiment

BACKGROUND AND OBJECTIVE

Treatment for attention deficit hyperactivity disorder (ADHD) requires a multifaceted approach including psychosocial interventions and pharmacological treatment. This study evaluates preferences for specific attributes associated with different long-acting stimulant treatment among US adults with ADHD.

METHODS

Patients completed an online, cross-sectional survey, incorporating a discrete choice experiment to assess preferences for attributes.

RESULTS

Analyses included 200 adults with ADHD (mean age 33.0 years; 60% self-reporting moderate severity); the mean (SD) Adult ADHD Self-Report Scale-v1.1 score was 45.9 (12.4). Overall, patients valued speed of onset most and risk of rebound least. Three population groups with distinct preferences were identified: side effect-driven (n=69, 35%), quick onset-driven (n=47, 24%) and quick onset and long duration-driven (n=84, 42%).

CONCLUSION

This study shows differences in how adults with ADHD value and assess benefit-risk trade-offs when considering the desired attributes of stimulant treatments, highlighting the importance of patient-physician shared decision-making to optimize the desired benefits of individualized treatment.

Pharmacogenetic Testing of Cytochrome P450 Drug Metabolizing Enzymes in a Case Series of Patients with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is associated with co-morbid psychiatric symptoms (disruptive behavior, anxiety, mood disorders, and psychosis) often requiring psychotropic medications. In this clinical case series of 35 patients with PWS, pharmacogenetic testing was obtained to determine allele frequencies predicting variations in activity of cytochrome (CYP) P450 drug metabolizing enzymes 2D6, 2B6, 2C19, 2C9, 3A4, and 1A2. Results were deidentified, collated, and analyzed by PWS genetic subtype: 14 deletion (DEL), 16 maternal uniparental disomy (UPD) and 5 DNA-methylation positive unspecified molecular subtype (PWS Unspec). Literature review informed comparative population frequencies of CYP polymorphisms, phenotypes, and substrate specificity. Among the total PWS cohort, extensive metabolizer (EM) activity prevailed across all cytochromes except CYP1A2, which showed greater ultra-rapid metabolizer (UM) status (p < 0.05), especially among UPD. Among PWS genetic subtypes, there were statistically significant differences in metabolizing status for cytochromes 2D6, 2C19, 2C9, 3A4 and 1A2 acting on substrates such as fluoxetine, risperidone, sertraline, modafinil, aripiprazole, citalopram, and escitalopram. Gonadal steroid therapy may further impact metabolism of 2C19, 2C9, 3A4 and 1A2 substrates. The status of growth hormone treatment may affect CYP3A4 activity with gender specificity. Pharmacogenetic testing together with PWS genetic subtyping may inform psychotropic medication dosing parameters and risk for adverse events.

Parent and Teacher Training Increases Medication Adherence for Primary School Children With Attention-Deficit/Hyperactivity Disorder

Objective: Attention-deficit/hyperactivity disorder (ADHD) is a common neurobiological disorder for which effective and safe medication is recommended as first-line treatment. However, many parents and teachers do not believe that ADHD is a disorder or do not accept medication treatment in China. Treatment is often short term or intermittent. Our study aimed to investigate the clinical effect of employing a 4-week, session-based training for both parents and teachers in improving medication adherence for primary school children with ADHD. Methods: From January 2018 to December 2018, a total of 5,118 primary school children were screened. Among 211 children diagnosed with ADHD, 116 were assigned to the intervention group and 95 to the control group. This study provided systematic training for parents and teachers in the intervention group. The training consisted of education about the disorder and ADHD behavioral intervention for both parents and teachers as well as classroom management techniques for just the teachers. A cluster randomized controlled trial (RCT) was conducted to investigate the effect of this training at 6 months follow-up. The study determined medication adherence using a questionnaire and scoring with a rating scale at baseline and at the 6 month follow-up endpoint. The questionnaire was self-report. Results: The study population had a relatively low rate of attention deficit hyperactivity disorder (4.1%) compared to the generally accepted prevalence. After the training, more parents and teachers believed that ADHD is a neurobiological disorder and that medication is the first line treatment. At 6 months follow-up, the Medication Adherence Report Scale (MARS) score for the intervention group was 22.8 ± 0.75 and 16.5 ± 1.63 for the control group (t = 5.217, P < 0.01). Based on parents' reports and medical records, 82 children (70.69%) were continuously taking medication for 6 months in the intervention group, while only 35 children (36.84%) were doing so in the control group. In the intervention group, the mean SNAP-IV score was 1.98 ± 0.42 at baseline but 0.99 ± 0.31 at 6-month follow-up. In the control group, the mean SNAP-IV score was 1.89 ± 0.47 at baseline but 1.37 ± 0.42 at 6-months follow-up (F = 2.67, P = 0.009). Factors influencing medication adherence for children with ADHD were parent's beliefs, teacher's beliefs, socioeconomic status, adverse effect, insurance coverage, gender, and trust of the medical system. Conclusions: Our findings indicate that comprehensive training programs improve the understanding of ADHD and medication adherence for both children's parents and teachers, providing a promising approach for improving clinical efficacy for children with ADHD.

Investigation of Efficacy of Short-Acting Methylphenidate (Ritalin) and Long-Acting (Matoride) on Symptoms of Attention Deficit Hyperactivity Disorder in Children Aged 6-18 Years: A Single-Blind, Randomized Clinical Trial

Background

This study aimed to evaluate the efficacy and safety of long-acting versus short-acting methylphenidate on the symptoms of attention deficit hyperactivity disorder (ADHD) in children and adolescents aged 6-18 years.

Materials and Methods

This single-blind, randomized clinical trial was conducted on 150 children and adolescents aged 6-18 years with ADHD based on the Diagnostic and Statistical Manual of Mental Disorder-5 criteria. The patients were randomly assigned to two groups (Matoride or Ritalin). In the first group, Ritalin was prescribed 2/3 times a day, and in the second group, Matoride was prescribed once a day for 3 weeks. The Conner's questionnaire was completed by the parents of the participants for evaluation of the performance and symptoms of ADHD in both groups at the beginning and 3 weeks after treatment. In addition, the incidence of any drug complications at the end of 3-week treatment period was evaluated.

Results

There were no statistically significant differences between the two groups before the intervention (P > 0.05) in the dimensions of attention deficit, emotional reaction, behavioral disorder, learning disorder, and impulsivity. At the postinterventional periods, behavioral disorder of the Ritalin group was statistically significantly lower than that of the Matoride group (P = 0.001). This treatment did not have a statistically significant effect on the total score of Conners (P = 0.255). Complications were seen in 58 cases (77.3%) of Matoride group and 49 ones (67.1%) of the Ritalin group. Weight loss in the Ritalin group was higher than that of the Matoride group (P = 0.019). Compared to the Ritalin group, anxiety was higher in the Matoride group (P = 0.022).

Conclusion

Given the similar effect of Matoride and Ritalin and no significant difference in drug complications, it seems that Matoride (slow release) can be used as an alternative to Ritalin (short acting).

A Single-Dose, Two-Way Crossover, Open-Label Bioequivalence Study of an Amphetamine Extended-Release Oral Suspension in Healthy Adults

Objective: The purpose of this study was to compare the pharmacokinetics of a new extended-release amphetamine oral suspension (AMP XR-OS) with a standard extended-release mixed amphetamine salts product, Adderall XR®. Method: In this single-dose, open-label, randomized, two-period, two-treatment crossover study, 42 healthy adult volunteers received 15 mL of AMP XR-OS in one period and a 30 mg Adderall XR capsule in another period (both containing 18.8 mg of amphetamine base) under fasted conditions. Blood samples were analyzed for d- and l-amphetamine concentrations, and pharmacokinetic parameters C_max, AUC_0-5, AUC_5-last, and AUC_inf were calculated to determine bioequivalence. Safety was monitored throughout the study. Results: The 90% confidence intervals (CIs) for the log-transformed C_max, AUC_0-5, AUC_5-last, and AUC_inf fell within the accepted 80% to 125% range for establishing bioequivalence for d- and l-amphetamine. The most common adverse events were nausea and decreased appetite. Conclusion: AMP XR-OS is bioequivalent to Adderall XR in healthy adult participants.

An update on the pharmacokinetic considerations in the treatment of ADHD with long-acting methylphenidate and amphetamine formulations

Introduction: Long-acting stimulant formulations are recommended as first-line pharmacotherapy for attention-deficit/hyperactivity disorder (ADHD). Over the past 20 years, extended-release (ER) methylphenidate (MPH) and amphetamine (AMP) formulations have evolved to include varying drug delivery technologies, enantiomers/salts, and dosage forms. All formulations are characterized by a unique pharmacokinetic profile that is closely mirrored by pharmacodynamic response allowing clinicians to individualize therapy based on their patient's clinical needs and dosing preferences.Areas covered: This review provides an update on the pharmacokinetic properties of approved and investigational ER MPH and AMP formulations and highlights pharmacokinetic features that clinicians should consider when selecting a long-acting stimulant.Expert opinion: Since there are no reliable biomarkers that can predict individualized response to long-acting stimulants, clinicians need to consider their distinctive pharmacokinetic properties, including the pharmacokinetic profile, rate and extent of absorption, variability, dose proportionality, bioequivalence, and potential for accumulation. Clinicians also need to understand that certain factors can contribute to increased variability in pharmacokinetics and potentially affect outcomes. Less invasive, high-throughput techniques and novel time-based scales are being developed to advance research on the pharmacokinetic-pharmacodynamic relationships of stimulants. Model-based pharmacokinetic-pharmacodynamic approaches can be applied to aid the development of novel formulations and individualize therapy with existing drugs.

Diagnosis and treatment of ADHD in children vs adults: What nurses should know

Attention-deficit/hyperactivity disorder (ADHD) commonly occurs in childhood and may persist into adulthood. Important differences exist between pediatric and adult ADHD with regard to symptoms, comorbidities, diagnosis, and management. Both patient populations benefit from a treatment plan tailored to individual patient needs, and the availability of new stimulant formulations contributes to treatment personalization. To guide nurses' clinical practice in improving ADHD treatment outcomes, this review examines the differences between pediatric and adult ADHD and new treatment options.

Lisdexamfetamine Dimesylate: A Review in Paediatric ADHD

Lisdexamfetamine dimesylate (lisdexamfetamine; Elvanse^®; Tyvense^®), an orally-active dexamfetamine prodrug, is indicated in the EU for the treatment of attention-deficit hyperactivity disorder (ADHD) in children aged ≥ 6 years (including adolescents) when the response to previous methylphenidate (MPH) treatment is clinically inadequate. The original approval of the drug was based on the results of phase III trials in children and adolescents with ADHD who had an inadequate response to previous pharmacotherapy (e.g. MPH) or were treatment naïve. In these studies, short-term treatment with flexibly-dosed lisdexamfetamine demonstrated greater efficacy than atomoxetine, based on a prospective comparison, and osmotic-release oral system (OROS)-MPH, based on a post hoc comparison. Improvements in ADHD symptoms were accompanied by improvements in health-related quality of life and functioning that were maintained as long as treatment with lisdexamfetamine was continued in a long-term extension of one of these trials. In subsequent phase IV head-to-head studies in adolescents with ADHD and an inadequate response to previous pharmacotherapy, lisdexamfetamine demonstrated greater efficacy than OROS-MPH when both medications were force-titrated, but not when they were flexibly-titrated. Lisdexamfetamine was generally well tolerated, with an adverse event profile (e.g. decreased appetite, headache, weight reduction, insomnia and irritability) typical of that reported for other stimulants. Thus, lisdexamfetamine provides an alternative option for the treatment of children and/or adolescents with ADHD who have not responded adequately to previous ADHD pharmacotherapies.

Cardiovascular Effects of Drugs Used to Treat Attention-Deficit/Hyperactivity Disorder: Part 1: Epidemiology, Pharmacology, and Impact on Hemodynamics and Ventricular Repolarization

Attention-deficit/hyperactivity disorder (ADHD) is a clinical syndrome characterized by persistent inattention, impulsivity, and hyperactivity. It is most commonly encountered in children and adolescents but may persist into adulthood. A variety of psychostimulant and nonpsychostimulant medications have proven to be successful in reducing inattention, impulsivity, and hyperactivity in those with ADHD. Psychostimulants used to treat ADHD include methylphenidate and related drugs and various amphetamine preparations. Non-psychostimulant medications used to treat ADHD include atomoxetine and two alpha-2 adrenergic agonists: guanfacine extended-release and clonidine extended-release. The psychostimulants and atomoxetine have been shown, on average, to increase heart rate by 3-10 beats/min, systolic blood pressure by 3-8 mm Hg, and diastolic blood pressure by 2-14 mm Hg. These drugs may also delay ventricular repolarization. The alpha-2 adrenergic agonists may reduce heart rate and blood pressure. For these reasons, there is concern about the safety of psychostimulant and nonpsychostimulant medications in patients with ADHD. In part 1 of this review, we discuss the epidemiology and natural history of ADHD, describe the pharmacology of drugs used to treat ADHD, and discuss in detail studies assessing the effects of ADHD drugs on blood pressure, heart or pulse rate, and electrocardiographic indices of ventricular repolarization.

Pharmacokinetics of a New Amphetamine Extended-Release Oral Suspension in Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

An extended-release amphetamine (AMP) oral suspension has been developed to facilitate medication ingestion and dose titration. This study sought to determine the pharmacokinetic (PK) profile of this new formulation in children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

This was an open-label, single-period, PK study in 29 pediatric participants with ADHD. Participants were stratified into age groups 1 (6-7 years), 2 (8-9 years), and 3 (10-12 years), and dosed with 15 mL extended-release AMP liquid suspension (equivalent to 30 mg mixed AMP salts) after an overnight fast. Blood samples were collected at prespecified time points and analyzed for d- and l-AMP concentrations. Key PK parameters included maximum plasma concentration (C_max), time to maximum plasma concentration, half-life (T_1/2), area under the curve from time 0 to last quantifiable concentration (AUC_last) and to infinity (AUC_inf), oral clearance (CL/F), and volume of distribution (Vz/F). The 95% confidence intervals (CIs) about the geometric means of the weight-normalized CL/F, Vz/F, and AUC_last were determined. Safety was also assessed.

RESULTS

All participants completed the study. As age increased, mean maximum and total exposure to AMP decreased; weight-normalized CL/F slightly increased, resulting in decreasing T_1/2 values with age. For d- and l-AMP, the 95% CIs for the geometric means of weight-normalized CL/F/kg and Vz/F/kg were within the 60%-140% range for groups 2 and 3, while those of weight-normalized AUC_last were within range for all age groups. Adverse events were mild and consistent with the safety profile of AMP.

CONCLUSIONS

Exposure (C_max, AUC_inf, and AUC_last) to AMP decreased with age, possibly as a result of the 30-mg/15-mL fixed dose across a range of weights (20-57 kg) and the consequent lower dose per kilogram in older participants, as well as the slight increase in clearance with age.

Single-Dose Pharmacokinetics of HLD200, a Delayed-Release and Extended-Release Methylphenidate Formulation, in Healthy Adults and in Adolescents and Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Current extended-release (ER) formulations of psychostimulants used for treatment of attention-deficit/hyperactivity disorder (ADHD) provide an extended duration of ADHD symptom control; however, the onset of efficacy can be protracted and variable, leaving the early morning untreated. The primary objective was to characterize the single-dose pharmacokinetics and tolerability of HLD200, an evening-dosed, delayed-release (DR) and ER formulation of methylphenidate (MPH), in healthy adults and in adolescents and children with ADHD.

METHODS

The pharmacokinetics and tolerability of a single, oral evening dose of HLD200 (54 mg) were evaluated in two single-center open-label studies: the first in healthy adults (n = 12) and the second in adolescents (n = 18) and children (n = 11) with ADHD. Primary pharmacokinetic endpoints were the rate and extent of MPH absorption (C_max and area under the curve [AUC]) and time to peak concentration (T_max). These parameters were calculated using noncompartmental analysis.

RESULTS

HLD200 produced a pharmacokinetic profile characterized by an 8- to 10-hour delay in MPH release, followed by a period of extended controlled release, resulting in an ascending absorption profile that coincided with the early morning and afternoon. Mean values (coefficient of variation [CV]%) of weight-adjusted pharmacokinetic parameters were similar in adults and in adolescents and children with ADHD: C_max ([ng/mL]/[mg/kg]) was 9.1 (35.2), 8.8 (34.5), and 7.4 (30.1); AUC_0-t ([ng · h/mL]/[mg/kg]) was 126.5 (35.5), 129.4 (34.8), and 129.7 (27.3); and T_max (hours) was 15.6 (11.1), 17.1 (14.5), and 17.7 (14.1), respectively. Intersubject variability in the mean time to achieve ascending plasma MPH concentrations of 2, 3, 4, and 5 ng/mL was low (CV: 7.8%-17.7%).

CONCLUSIONS

Evening-dosed HLD200 produces the intended DR and ER pharmacokinetic profile that provides a consistent predictable delay in initial MPH release until the early morning, followed by extended release across the day. The body weight-adjusted pharmacokinetics of HLD200 were similar between adults and adolescents and children with ADHD.

Beyond the pill: new medication delivery options for ADHD

Successful treatment of pediatric disorders has necessitated the development of alternative medication formulations, as children may prefer alternative dosage forms to tablets or capsules. This is especially true for attention-deficit/hyperactivity disorder (ADHD), which is one of the most common chronic pediatric conditions and often involves children with a variety of overlapping physical, psychological, or neurodevelopmental disorders. A special challenge for developing alternative dosage forms for ADHD treatment is the incorporation of a once-daily long-acting formulation. Traditional ADHD medication formulations have been limited, and issues surrounding prescribed dosing regimens-including poor medication adherence, difficulty swallowing, and the lack of dosing titration options-persist in ADHD treatment. In other disease areas, the development of alternative formulations has provided options for patients who have issues with consuming solid dosage forms, particularly children and individuals with developmental disorders. In the light of these new developments, several alternative formulations for ADHD medications are under development or have recently become available. This article reviews the various strategies for developing alternative dosage forms in other disease areas and discusses the application of these strategies in ADHD treatment. Alternative dosage forms may increase medication adherence, compliance, and patient preference and, therefore, improve the overall treatment for ADHD.

Methylphenidate disintegration from oral formulations for intravenous use by experienced substance users

BACKGROUND AND AIMS

Methylphenidate (MPH) is a prescription stimulant used to treat attention-deficit hyperactivity disorder. MPH is currently the preferred substance among most intravenous (i.v.) substance users in Iceland. Four types of MPH preparations were available in Iceland at the time of study: Immediate-release (IR), sustained-release (SR), osmotic controlled-release oral delivery (OROS) tablet and osmotic-controlled release (OCR). MPH OROS has previously been rated the least desirable by i.v. users and we hypothesized that this was associated with difficulty of disintegrating MPH from OROS formulation. The aim of the study was to measure the amount of MPH and the viscosity of the disintegrated solutions that were made from the four MPH formulations by four i.v.-users and non-users.

METHODS

A convenience sample of four i.v. substance users and 12 non-users. Non-users imitated the methods applied by experienced i.v. substance users for disintegrated MPH formulations.

RESULTS

Both groups managed to disintegrate over 50% of MPH from IR and SR formulations but only 20% from OROS (p<0.0001). The viscosity of the disintegrated MPH was significantly higher for MPH OROS and MPH OCR and the preparation was significantly more time-consuming than for the other MPH samples. No differences were observed between users and non-users.

CONCLUSIONS

To our knowledge, this is the first investigation of viscosity and the amount of disintegrated MPH from prescription drugs for i.v. use. The results indicate that the ease of disintegration, amount of MPH and viscosity may explain the difference in popularity for i.v. use between different MPH formulations.

Review of Lisdexamfetamine Dimesylate in Adults With Attention-Deficit/Hyperactivity Disorder

Lisdexamfetamine dimesylate (LDX) is the first prodrug stimulant used for the treatment of attention-deficit/hyperactivity disorder (ADHD) dosed once daily. Due to its long-acting properties, LDX remains pharmacologically inactive until an enzymatic process predominantly associated with red blood cells converts it to the active ingredient, d-amphetamine and the amino acid lysine. The efficacy of LDX over placebo has been demonstrated in several studies in adults with moderate to severe ADHD with significant improvements noted in ADHD rating scales, Clinical Global Improvement scores, and assessments of executive function, for all doses of LDX (30-70 mg daily). Lisdexamfetamine dimesylate has demonstrated efficacy at 14 hours post dose in adults and may be used as a long-acting stimulant for managing ADHD symptoms, which may extend late into the day. Lisdexamfetamine dimesylate has demonstrated a safety profile consistent with long-acting stimulants use. Relevant English language articles were identified through computerized searches of MEDLINE (PubMed and EMBASE) from 1995 to 2016 using the following search terms: lisdexamfetamine dimesylate, attention-deficit hyperactivity disorder, NRP104, and Vyvanse.

A Comparison of the Pharmacokinetics of Methylphenidate Extended-Release Orally Disintegrating Tablets With a Reference Extended-Release Formulation of Methylphenidate in Healthy Adults

Extended-release (ER) methylphenidate (MPH) is a first-line treatment for attention-deficit/hyperactivity disorder. A methylphenidate extended-release orally disintegrating tablet (MPH XR-ODT) has recently been developed. This was a randomized, open-label, 3-period, 3-treatment study comparing the bioavailability and absorption of 2 MPH XR-ODT formulations with an MPH ER reference medication. Here we report the 2 treatments comparing the commercial MPH XR-ODT formulation and reference medication. Following a ≥10-hour fast, 42 healthy adults received 60 mg of reference medication or MPH XR-ODT (2 × 30 mg). The following pharmacokinetic (PK) parameters were calculated for total methylphenidate (d + l): maximum plasma concentration (C_max ), time to maximum plasma concentration (T_max ), terminal half-life (T_1/2 ), and areas under the concentration-time curve from time zero to the time of the last quantifiable concentration (AUC_last ), and from time zero extrapolated to infinity (AUC_inf ). Secondary PK end points included partial AUCs. Safety was also assessed. Overall systemic exposure to methylphenidate after MPH XR-ODT administration was similar to that of the reference product, and the concentration-time profiles for MPH XR-ODT and the reference drug were similar, although the C_max was 25% higher for MPH XR-ODT. The most common treatment-emergent adverse events were nausea (6) and anxiety (4), which were similar across treatments.

Fed and Fasted Administration of a Novel Extended-Release Methylphenidate Orally Disintegrating Tablet Formulation for the Treatment of ADHD

Extended-release methylphenidate is a first-line treatment for attention-deficit/hyperactivity disorder. A methylphenidate extended-release orally disintegrating tablet (MPH XR-ODT) has recently been developed. Here we report an open-label, randomized, 2-period, 2-treatment crossover study to determine the effect of food on the bioavailability of a single 60-mg dose of MPH XR-ODT in healthy adults. Blood samples were collected predose through 36 hours postdose. Maximum plasma concentration (C_max ), time to maximum plasma concentration (T_max ), terminal elimination half-life (T_1/2 ), overall systemic exposure (AUC_last and AUC_inf ), and partial areas under the concentration curve (AUC_0-3 , AUC_3-7 , and AUC_7-12 ) were calculated. In total, 48 participants completed the study. For total methylphenidate from MPH XR-ODT, the lower limit of the 90% confidence interval (CI) around the geometric mean ratio (GMR, fed/fasted) for C_max was below 80%, indicating a slightly decreased rate of absorption with food, whereas the 90%CIs around the GMRs of AUC_last and AUC_inf were within the 80%-125% limits, suggesting no food effect on exposure. The most common adverse events (AEs) were palpitations and decreased appetite. No serious, unusual, or unexpected AEs were reported. Thus, food had no substantial effect on overall bioavailability of MPH XR-ODT, which may be an important factor for some patients.

Psychiatric medication preferences of sports psychiatrists

OBJECTIVES

When prescribing psychiatric medications to athletes, it is important to consider issues that are especially important for this population, including side effects, safety concerns, and anti-doping policies. Only one report, from 2000, describes the prescribing preferences of psychiatrists who work with athletes. This manuscript aims to update the findings from that report, so as to help inform prescribing practices of primary care physicians, psychiatrists, and other clinicians who work with athletes.

METHODS

Physician members of the International Society for Sports Psychiatry (ISSP) were sent an email invitation in 2016 to complete an anonymous web-based survey on psychiatric medication prescribing preferences in working with athletes with a variety of mental health conditions.

RESULTS

Forty of 100 (40%) members of the ISSP who identified as physicians and who were emailed the survey ultimately completed it. Top choices of psychiatric medications for athletes across categories assessed included: bupropion for depression without anxiety and without bipolar spectrum disorder; escitalopram for generalized anxiety disorder; melatonin for insomnia; atomoxetine for attention-deficit/hyperactivity disorder; lamotrigine for bipolar spectrum disorders; and aripiprazole for psychotic disorders.

CONCLUSION

Prescribers of psychiatric medications for athletes tended to favor medications that are relatively more energizing and less likely to cause sedation, weight gain, cardiac side effects, and tremor. Additionally, prescribing preferences for athletes diverged from many of the prescribing trends seen for patients within the general population, in keeping with the assumption that different factors are considered when prescribing for athletes versus for the general population.

A randomized crossover study to assess the pharmacokinetics of a novel amphetamine extended-release orally disintegrating tablet in healthy adults

OBJECTIVES

In this pharmacokinetic (PK) study in healthy adults, we sought to: (1) compare the PK properties of a novel amphetamine extended-release orally disintegrating tablet formulation (Adzenys XR-ODT™ [AMP XR-ODT]) to a reference extended-release mixed amphetamine salts (MAS ER) formulation and (2) assess the effect of food on AMP XR-ODT.

METHODS

Forty-two adults were enrolled in a single-dose, open-label, 3-period, 3-treatment, randomized crossover study and received an 18.8-mg dose of AMP XR-ODT (fasted or fed) or equivalent dose (30 mg) of MAS ER (fasted). Plasma samples were analyzed for d-and l-amphetamine. Maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax), elimination half-life (T1/2), area under the concentration-time curve from time zero to last quantifiable concentration (AUClast), from time zero to infinity (AUCinf), relevant partial AUCs, and weight-normalized clearance (CL/F/kg) were assessed. The PK parameters were compared across treatments using an ANOVA. Safety was also assessed.

RESULTS

A total of 39 adults completed this study. The geometric mean ratios (90% confidence interval [CI]) for AMP XR-ODT/MAS ER Cmax, AUC5-last, AUClast, and AUCinf were within 80%-125% for both d-and l-amphetamine. The 90% CIs for AUC0-5 were slightly below the 80%-125% range. When AMP XR-ODT was administered with food, there was a slight decrease in the d-and l-amphetamine Cmax and approximately a 2-hour delay in Tmax. The most common adverse events reported (>5% of participants) were dry mouth, palpitations, nausea, dizziness, headache, anxiety, and nasal congestion.

CONCLUSIONS

AMP XR-ODT displayed a PK profile similar to MAS ER, and no clinically relevant food effect was observed.

Lisdexamfetamine: A Review in ADHD in Adults

Lisdexamfetamine dimesylate (lisdexamfetamine) is a long-acting amfetamine prodrug with a convenient once-daily oral regimen that offers the potential for improved adherence and reduced abuse compared with short-acting preparations of amfetamines. Lisdexamfetamine (as Elvanse Adult(®); Tyvense Adult™) has been approved for use in adults with attention-deficit hyperactivity disorder (ADHD) under the EU decentralization procedure, with the first approvals in the UK, Sweden and Denmark. This approval reflects the results of three short-term trials in adults with ADHD in which fixed- or flexible-dose lisdexamfetamine produced significantly greater improvements than placebo in ADHD symptoms, overall functioning, executive functioning (including in patients with significant pre-existing impairment) and quality of life. Of note, a post hoc analysis of one of these studies suggested that the response to lisdexamfetamine was generally similar in treatment-naïve patients and those who had already received-and not responded satisfactorily to-previous ADHD therapies, including methylphenidate (MPH). Two further studies demonstrated the longer-term effectiveness of flexible-dose lisdexamfetamine in reducing ADHD symptoms, albeit maintenance of efficacy required ongoing treatment with the drug. Lisdexamfetamine was generally well tolerated in clinical trials, with an adverse event profile typical of that reported for other long-acting stimulants. Head-to-head comparisons with other long-acting agents, notably MPH and atomoxetine, are lacking. Nonetheless, on the basis of the available data, lisdexamfetamine provides a useful alternative option for the treatment of adults with ADHD, including those who have not responded adequately to previous ADHD therapies, including MPH.

Expert Opinion and Recommendations for the Management of Attention-Deficit/Hyperactivity Disorder in Correctional Facilities

There has been considerably less research on the management of adult attention-deficit/hyperactivity disorder (ADHD) among the inmates of correctional facilities than in the general community. While the successful identification and management of ADHD in the adult correctional setting offer potential benefits to the individuals themselves, to institutional staff, and to wider society, their implementation represents significant challenges. These include high prevalence rates, the low level of ADHD recognition, the high incidence of comorbid psychiatric disorders, and the high risk of abuse and diversion of prescribed medications. Here, the authors provide an overview of current recommendations for the identification and management of adults with ADHD in correctional settings and discuss possible strategies for their further development.

Bioequivalence of Sandoz methylphenidate osmotic-controlled release tablet with Concerta® (Janssen-Cilag)

The aim was to assess the bioequivalence of Sandoz methylphenidate osmotic-controlled release (OCR) tablets (Sandoz [Methylphenidate[ MPH OCR) with Concerta®, a methylphenidate formulation indicated for the treatment of attention deficit/hyperactivity disorder (ADHD). Four open-label, randomized, single-dose, two-way crossover bioequivalence studies were conducted in healthy subjects: three fasting studies with 54-, 36- and 18-mg doses of methylphenidate, and one fed study with the 54-mg dose. The d- and l-threo-methylphenidate plasma levels were quantified using liquid chromatographic methods with tandem mass spectrometry (LC MS/MS). Bioequivalence of the formulations was accepted if the 90% geometric confidence intervals of the ratio of least-squares means of Sandoz MPH OCR to Concerta® of ln-transformed area under the curve (AUC_0–t) and C_max were within the acceptance range of 80–125%. All studies met the bioequivalence criteria, and 90% geometric confidence intervals for AUC_0–t and C_max were within the predefined range. All plasma concentration time curves for Sandoz MPH OCR under fasting conditions showed a biphasic profile comparable with Concerta®, confirmed by bioequivalence of the partial metrics AUC_0–2h, AUC_2-24 h, C_{max(0–2 h)} and C_{max(2–24 h)}. Both products were well tolerated and no relevant differences in the safety profiles were observed. It was concluded that Sandoz MPH OCR is bioequivalent to Concerta® in terms of rate and extent of absorption when administered as a single dose of one extended-release tablet of 54, 36, or 18 mg under fasting conditions and at a dose of 54 mg under fed conditions.

Adderall XR® and Vyvanse™

Adderall XR® (MAS XR) and Vyvanse™ (LDX) are both schedule II amphetamine-based central nervous system stimulants indicated for the treatment of attention-deficit/hyperactivity disorder. Differences among the two primarily involve dosage form, pharmacokinetic profiles, and abuse potential. MAS XR and LDX are both long-acting stimulants with an approximate duration of action of 10 hours. The long-acting property of LDX is secondary to its prodrug formulation, whereas MAS XR utilizes bead filled capsules that mimic twice daily dosing upon administration. MAS XR is a substrate of CYP 2D6 while LDX does not utilize the cytochrome P450 enzymes for metabolism. There are few efficacy studies that directly compare LDX and MAS XR. There are no head to head abuse liability studies for MAS XR and LDX; however, the prodrug formulation of LDX is proposed to have lower abuse potential.