Lisdexamfetamine dimesylate: a new therapeutic option for attention-deficit hyperactivity disorder

Review of lisdexamfetamine dimesylate in children and adolescents with attention deficit/hyperactivity disorder

OBJECTIVE

Lisdexamfetamine dimesylate is a stimulant prodrug with low abuse and diversion potential that is used in treatment of attention deficit hyperactivity disorder (ADHD) in children, adolescents and adults. This current literature review article aims to examine safety and efficacy of LDX in children and adolescents for the treatment of ADHD based on currently available data.

METHODS

Relevant English language articles were identified through computerized searches of the MEDLINE database (PubMed and EMBASE) and clinical trials registry up to January 2020 using the following search terms: lisdexamfetamine dimesylate, pro-drug stimulant, attention-deficit and hyperactivity disorders, ADHD, safety, efficacy, children, adolescents, Vyvanse. Forty-two articles were reviewed, 34 of which were included into this review, selected by the limit "clinical trials". This article represents the pharmacological profile, efficacy and safety data of LDX for the treatment of ADHD in children and adolescents.

RESULTS

The collection of studies reviewed identified that LDX was both safe and efficacious in the treatment of ADHD. The most commonly exhibited side effects were appetite suppression, weight loss, headache and insomnia. In comparison to placebo, LDX significantly improved ADHD symptoms and overall quality of life in children and adolescents. In comparison to atomoxetine, LDX showed statistically significant improvements in inattention, impulsivity, and activities of daily living. In comparison to OROS-MPH and placebo, LDX and OROS-MPH showed improvements with the CGI-I score, and ADHD-RS-IV, however, LDX was superior.

CONCLUSION

Patients have seen statistically significant improvements in their ADHD symptomatology in the classroom environment, health related quality of life, and their overall behavior in comparison to placebo, atomoxetine, and OROS-MPH. However, clinical judgment should be utilized when prescribing LDX due to patient specific needs and the side effect profile.

Phase II/III Study of Lisdexamfetamine Dimesylate in Japanese Pediatric Patients with Attention-Deficit/Hyperactivity Disorder

Objective: To further define the efficacy and safety profiles of lisdexamfetamine dimesylate (LDX) in Japanese pediatric patients with attention-deficit/hyperactivity disorder (ADHD). Methods: This was a multicenter, randomized, double-blind, placebo-controlled study of LDX 30, 50, or 70 mg/day for 4 weeks in 76 patients 6-17 years of age with ADHD in Japan. The primary efficacy endpoint was the change in the ADHD Rating Scale-IV (ADHD-RS-IV) total score from baseline to 4 weeks. Secondary efficacy endpoints were: Conners' Third Edition (Japanese version) Parent Rating Scale (Conners 3), Clinical Global Impression-Improvement (CGI-I) scale, and Parent Global Assessment (PGA) scale. Results: Change in the ADHD-RS-IV total score from baseline to 4 weeks was significantly greater (p < 0.0001) in all LDX dosage groups versus placebo (30 mg, -16.38; 50 mg, -18.10; 70 mg, -16.47; placebo, -2.78). At all time points, improvements (decreases) in the ADHD-RS-IV total score were significantly greater in all LDX groups versus placebo. At weeks 3 and 4, improvements from baseline in Conners 3 inattention plus hyperactivity/impulsivity subscale scores were significantly greater (p ≤ 0.0082) for all LDX dosages versus placebo. At week 4, the proportion of LDX-treated patients "much improved" or "very much improved" was 61%-71% on the CGI-I scale (p ≤ 0.0019) and 56%-65% on the PGA scale (p ≤ 0.0170). LDX was generally well tolerated. The most frequent treatment-emergent adverse events (AEs) were decreased appetite, headache, and initial insomnia. No severe/serious AEs occurred, and no AEs specific to Japanese patients were evident. Conclusions: The superiority of LDX 30, 50, and 70 mg/day over placebo was confirmed in Japanese pediatric patients with ADHD, and no major safety or tolerability concerns were identified.

Long-term study of lisdexamfetamine dimesylate in Japanese children and adolescents with attention-deficit/hyperactivity disorder

AIMS

As an extension of a phase 2/3 study evaluating the efficacy and safety of lisdexamfetamine dimesylate (LDX) 30, 50, or 70 mg/d for 4 weeks in Japanese patients aged 6-17 years with attention-deficit/hyperactivity disorder (ADHD), this study evaluated its long-term safety and efficacy.

METHODS

This was a multicenter, open-label study of LDX for 53 weeks. Safety was assessed by regular medical examination for treatment-emergent adverse events (TEAEs); regular recording of body weight, vital signs, and laboratory test values; and completion of dependence questionnaires. Efficacy was assessed using Japanese versions of the ADHD-Rating Scale-IV (ADHD-RS-IV) and Conners' 3rd edition Parent Rating Scale (Conners 3); plus Clinical Global Impression-Improvement (CGI-I), Clinical Global Impression-Severity, and Parent Global Assessment (PGA) scales.

RESULTS

Of 132 enrolled patients, 104 completed the trial. Most frequent treatment-related TEAEs were decreased appetite (73.5%), initial insomnia (39.4%), and weight decrease (22.0%). Most TEAEs were mild (82.6% of patients). There were no serious or severe TEAEs or deaths. No treatment-related TEAEs were associated with blood pressure or pulse rate, and no patient had a QTcF interval >500 ms. Statistically significant improvement from baseline to week 53 was observed in the mean ADHD-Rating Scale-IV total score and mean Conners 3 subscale scores. Most patients showed improvement on the CGI-I (78%) and PGA (76.5%) scales.

CONCLUSIONS

No significant safety issues were observed with LDX 30, 50, or 70 mg/d administered for 1 year in Japanese children and adolescents with ADHD. LDX was associated with long-term reductions in ADHD symptoms and severity.

Drug-induced endocrine blood pressure elevation

Patients with uncontrolled hypertension are at risk for cardiovascular complications. The majority of them suffers from unidentified forms of hypertension and a fraction has so-called secondary hypertension with an identifiable cause. The patient's medications, its use of certain herbal supplements and over-the-counter agents represent potential causal factors for secondary hypertension that are often overlooked. The current review focuses on drugs that are likely to elevate blood pressure by affecting the human endocrine system at the level of steroid synthesis or metabolism, mineralocorticoid receptor activity, or by affecting the catecholaminergic system. Drugs with known adverse effects but where benefits outweigh their risks, drug candidates and market withdrawals are reviewed. Finally, potential therapeutic strategies are discussed.

Effects of lisdexamfetamine on plasma steroid concentrations compared with d-amphetamine in healthy subjects: A randomized, double-blind, placebo-controlled study

The novel d-amphetamine prodrug lisdexamfetamine is applied to treat attention-deficit/hyperactivity disorder (ADHD). d-Amphetamine releases dopamine and norepinephrine and stimulates the hypothalamic-pituitary-adrenal (HPA) axis, which may contribute to its reinforcing effects and risk of abuse. However, no data is currently available on the effects of lisdexamfetamine on circulating steroids. This randomized, double-blind, placebo-controlled, cross-over study evaluated the effects of equimolar doses of d-amphetamine (40 mg) and lisdexamfetamine (100 mg) and placebo on circulating steroids in 24 healthy subjects. Plasma steroid and d-amphetamine levels were determined up to 24 h. Delayed increase and peak levels of plasma d-amphetamine concentrations were observed following lisdexamfetamine treatment compared with d-amphetamine administration, however the maximal concentrations and total exposure (area under the curve [AUC]) were similar. Lisdexamfetamine and d-amphetamine significantly enhanced plasma levels of adrenocorticotropic hormone, glucocorticoids (cortisol, cortisone, corticosterone, 11-dehydrocorticosterone, and 11-deoxycortisol), androgens (dehydroepiandrosterone, dehydroepiandrosterone sulfate, and Δ4-androstene-3,17-dione [androstenedione]), and progesterone (only in men) compared with placebo. Steroid concentration-time curves were shifted to later time points due to a non-significantly later onset following lisdexamfetamine administration than after d-amphetamine, however maximal plasma steroid concentrations and AUCs did not differ between the active treatments. None of the active treatments altered plasma levels of the mineralocorticoids aldosterone and 11-deoxycorticosterone or the androgen testosterone compared with placebo. The effects of the amphetamines on glucocorticoid production were similar to those that were previously reported for methylphenidate (60 mg) but weaker than those for the serotonin releaser 3,4-methylenedioxymethamphetamine (MDMA; 125 mg) or direct serotonin receptor agonist lysergic acid diethylamide (LSD; 0.2 mg). Lisdexamfetamine produced comparable HPA axis activation and had similar pharmacokinetics than d-amphetamine, except for a delayed time of onset. Thus, serotonin (MDMA, LSD) may more effectively stimulate the HPA axis than dopamine and norepinephrine (D-amphetamine).

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.

Pharmacokinetics and Pharmacodynamics of Lisdexamfetamine Compared with D-Amphetamine in Healthy Subjects

Rationale: Lisdexamfetamine is a prodrug of D-amphetamine used for the treatment of attention-deficit/hyperactivity disorder (ADHD). Lisdexamfetamine is thought to have a prolonged pharmacokinetic profile compared with oral D-amphetamine, possibly associated with lower drug liking and a lower risk of oral misuse. However, differences in the pharmacokinetics and pharmacodynamics of lisdexamfetamine and D-amphetamine have not been directly compared. Methods: Equimolar doses of D-amphetamine (40 mg) and lisdexamfetamine (100 mg), and placebo were administered in 24 healthy subjects in a randomized, double-blind, placebo-controlled, cross-over study. Plasma concentrations of amphetamine, subjective effects, and vital signs were repeatedly assessed. The pharmacokinetic parameters were determined using compartmental modeling. Results: The increase in plasma concentrations of amphetamine had a 0.6 ± 0.6 h (mean ± SD) longer lag time and reached peak levels 1.1 ± 1.5 h later after lisdexamfetamine administration compared with D-amphetamine administration, but no differences in maximal concentrations or total exposure (AUC) were found between the two treatments. Consistent with the pharmacokinetics, the subjective and cardiovascular stimulant effects of lisdexamfetamine also occurred later compared with D-amphetamine. However, no differences in peak ratings of potentially abuse-related subjective drug effects (e.g., drug liking, drug high, stimulation, happy, well-being, and self-confidence) were observed after lisdexamfetamine administration compared with D-amphetamine administration. Lisdexamfetamine and D-amphetamine also produced similar peak increases in mean arterial blood pressure, heart rate, body temperature, pupil size, and adverse effects. Conclusion: The pharmacokinetics and pharmacodynamics of lisdexamfetamine are similar to D-amphetamine administered 1h later. Lisdexamfetamine is likely associated with a similar risk of oral abuse as D-amphetamine. The study was registered at ClinicalTrials.gov (NCT02668926).

Novel pharmacologic treatment in acute binge eating disorder - role of lisdexamfetamine

Binge eating disorder (BED) is the most common eating disorder and an important public health problem. It is characterized by recurrent episodes of excessive food consumption accompanied by a sense of loss of control over the binge eating behavior without the inappropriate compensatory weight loss behaviors of bulimia nervosa. BED affects both sexes and all age groups and is associated with medical and psychiatric comorbidities. Until recently, self-help and psychotherapy were the primary treatment options for patients with BED. In early 2015, lisdexamfetamine dimesylate, a prodrug stimulant marketed for attention deficit hyperactive disorder, was the first pharmacologic agent to be approved by the US Food and Drug Administration for the treatment of moderate or severe BED in adults. This article summarizes BED clinical presentation, and discusses the pharmacokinetic profile, efficacy, and safety of lisdexamfetamine dimesylate in the treatment of BED in adults.

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.

Effects of the dopamine/norepinephrine releaser phenmetrazine on cocaine self-administration and cocaine-primed reinstatement in rats

RATIONALE

Like other monoamine releasers such as D-amphetamine, chronic treatment with phenmetrazine can attenuate cocaine self-administration in monkeys.

OBJECTIVES

The present studies extended this finding to rodents and to cocaine-primed reinstatement, a putative laboratory animal model of relapse.

METHODS

In experiment 1, rats self-administered food pellets or injections of 0.19 mg/kg cocaine (i.v.) under a progressive-ratio schedule. When responding was stable, subcutaneous osmotic pumps were implanted containing saline or (+)-phenmetrazine (25 or 50 mg/kg per day). In experiment 2, rats self-administered injections of 0.75 mg/kg cocaine under a fixed-ratio 1 schedule in daily 6-h sessions. When responding was stable, rats were removed from the self-administration environment for 7 days and treated continuously with saline, 5 mg/kg per day D-amphetamine or phenmetrazine (25 or 50 mg/kg per day) via osmotic pumps. Rats were then returned to the self-administration context while treatment continued, and responding was extinguished by removing response-contingent stimulus changes and cocaine injections. Once responding was extinguished, reinstatement tests were conducted using cocaine injections (10 mg/kg i.p.).

RESULTS

Phenmetrazine decreased self-administration of cocaine, but not food pellets, during the 14-day treatment period; effects persisted for several days after treatment was discontinued. Moreover, cocaine-induced increases in responding during the reinstatement test were attenuated by D-amphetamine and both phenmetrazine doses.

CONCLUSIONS

These results extend the study of the effects of phenmetrazine on cocaine self-administration to a rodent model, and provide further support for the use of monoamine releasers as agonist medications for cocaine abuse.

Associations of sleep disturbance with ADHD: implications for treatment

Attention-deficit/hyperactivity disorder (ADHD) is commonly associated with disordered or disturbed sleep. The relationships of ADHD with sleep problems, psychiatric comorbidities and medications are complex and multidirectional. Evidence from published studies comparing sleep in individuals with ADHD with typically developing controls is most concordant for associations of ADHD with: hypopnea/apnea and peripheral limb movements in sleep or nocturnal motricity in polysomnographic studies; increased sleep onset latency and shorter sleep time in actigraphic studies; and bedtime resistance, difficulty with morning awakenings, sleep onset difficulties, sleep-disordered breathing, night awakenings and daytime sleepiness in subjective studies. ADHD is also frequently coincident with sleep disorders (obstructive sleep apnea, peripheral limb movement disorder, restless legs syndrome and circadian-rhythm sleep disorders). Psychostimulant medications are associated with disrupted or disturbed sleep, but also ‘paradoxically’ calm some patients with ADHD for sleep by alleviating their symptoms. Long-acting formulations may have insufficient duration of action, leading to symptom rebound at bedtime. Current guidelines recommend assessment of sleep disturbance during evaluation of ADHD, and before initiation of pharmacotherapy, with healthy sleep practices the first-line option for addressing sleep problems. This review aims to provide a comprehensive overview of the relationships between ADHD and sleep, and presents a conceptual model of the modes of interaction: ADHD may cause sleep problems as an intrinsic feature of the disorder; sleep problems may cause or mimic ADHD; ADHD and sleep problems may interact, with reciprocal causation and possible involvement of comorbidity; and ADHD and sleep problems may share a common underlying neurological etiology.

The use of lisdexamfetamine dimesylate for the treatment of ADHD and other psychiatric disorders

Lisdexamfetamine dimesylate (LDX) is a long-acting oral prodrug stimulant. It is inactive until enzymatically hydrolyzed in the blood to active D-amphetamine. The pharmacological action of this compound involves blocking norepinephrine (NE) and dopamine reuptake into presynaptic neurons and promoting the release of NE and dopamine into the extraneuronal space. LDX has been approved for treating ADHD, which is the most common psychiatric disorder in children and adolescents. Also, LDX has been proposed for other psychiatric conditions related with dopaminergic and NE CNS. LDX is the first long-acting oral prodrug indicated for the treatment of ADHD in children (6-12 years), adolescents (13-17 years) and in adults in the USA and Canada, whereas, in Europe, LDX is licensed in several countries for the treatment of children and adolescents with ADHD who have had a clinically inadequate response to methylphenidate. This article covers the most important pharmacological aspects of LDX as well as data on the efficacy, tolerability and safety of this long-acting amphetamine prodrug collected from clinical studies recently published in the literature.

Isotope-dilution mass spectrometric quantification of the prodrug lisdexamfetamine in human urine in doping control analysis

RATIONALE

Therapeutic approaches concerning attention-deficit hyperactivity disorder (ADHD) commonly include the administration of drugs amplifying cerebral dopamine and norepinephrine signals. Among these, compounds belonging to the Prohibited List as established by the World Anti-Doping Agency (WADA) are present such as amfetamine or methylphenidate, and abuse of these can result in sanctions for athletes. The recently approved therapeutic lisdexamfetamine represents a slow-release prodrug of amfetamine for ADHD treatment. In order to support doping control laboratories in differentiating the abuse of amfetamine from a therapeutic administration of lisdexamfetamine, the determination of the prodrug from urine is desirable. Since approximately 2% of lisdexamfetamine are eliminated intact into urine, a liquid chromatography/high-resolution/high accuracy mass spectrometric method was developed, allowing the target analyte and one of its metabolites (4-hydroxyamfetamine sulfate) to be accurately quantified.

METHODS

Urine samples were fortified with fourfold deuterated lisdexamfetamine and analyzed directly using ultrahigh-performance liquid chromatography (UHPLC) interfaced via electrospray ionization to a second-generation quadrupole-orbitrap mass spectrometer. The assay was characterized concerning specificity, limits of quantification (0.15-5 ng/mL), intraday and interday imprecision (4-22%), accuracy (90-120%), linearity, and ion suppression/enhancement effects. A patient's urine samples were analyzed to provide proof-of-principle data demonstrating that the intact prodrug lisdexamfetamine is detectable in urine up to 11 h post-administration at concentrations up to 80 ng/mL. Moreover, amfetamine and sulfoconjugated 4-hydroxyamfetamine were measured, yielding up to 1146 and 56 ng/mL, respectively.

CONCLUSIONS

Considering the observed comparably low urinary concentrations of lisdexamfetamine and 4-hydroxyamfetamine sulfate, the preferred minimally labor-intense sample preparation, and the necessity of fast and robust result generation, the employed instrumental setup proved fit-for-purpose in sports drug testing.

Lisdexamfetamine prodrug activation by peptidase-mediated hydrolysis in the cytosol of red blood cells

Lisdexamfetamine dimesylate (LDX) is approved as a once-daily treatment for attention-deficit/hyperactivity disorder in children, adolescents, and adults in some countries. LDX is a prodrug comprising d-amphetamine covalently linked to l-lysine via a peptide bond. Following oral administration, LDX is rapidly taken up from the small intestine by active carrier-mediated transport, probably via peptide transporter 1. Enzymatic hydrolysis of the peptide bond to release d-amphetamine has previously been shown to occur in human red blood cells but not in several other tissues. Here, we report that LDX hydrolytic activity resides in human red blood cell lysate and cytosolic extract but not in the membrane fraction. Among several inhibitors tested, a protease inhibitor cocktail, bestatin, and ethylenediaminetetra-acetic acid each potently inhibited d-amphetamine production from LDX in cytosolic extract. These results suggest that an aminopeptidase is responsible for hydrolytic cleavage of the LDX peptide bond, although purified recombinant aminopeptidase B was not able to release d-amphetamine from LDX in vitro. The demonstration that aminopeptidase-like activity in red blood cell cytosol is responsible for the hydrolysis of LDX extends our understanding of the smooth and consistent systemic delivery of d-amphetamine by LDX and the long daily duration of efficacy of the drug in relieving the symptoms of attention-deficit/hyperactivity disorder.

What place for lisdexamfetamine in children and adolescents with ADHD?

Attention deficit hyperactivity disorder (ADHD) is the commonest behavioural disorder in the UK, affecting 2-5% of school-aged children and young people.(1) Guidelines from the National Institute for Health and Care Excellence (NICE) state that medication is not indicated as first-line treatment for school-age children and young people with ADHD, but should be reserved for those with severe symptoms and impairment, or those with moderate levels of impairment who have refused non-drug interventions, or those whose symptoms have not responded sufficiently to parent-training/education programmes or group psychological treatment.(2) Current drug options include methylphenidate (first-line), atomoxetine (first- or second-line) or dexamfetamine (second- or third-line).(2) Lisdexamfetamine (Elvanse-Shire Pharmaceuticals) is a prodrug of dexamfetamine, licensed as part of a comprehensive treatment programme for ADHD in children aged 6 years and over when response to previous methylphenidate treatment is considered clinically inadequate.(3,4) Here we review the place of lisdexamfetamine in the management of ADHD in children and adolescents.