Drug Monograph

Lisdexamfetamine

Lisdexamfetamine dimesylate · Vyvanse
CNS stimulant prodrug (DEA Schedule II) · Oral capsule / chewable tablet · ADHD & Binge Eating Disorder
Pharmacokinetic Profile
Active Moiety
Dextroamphetamine (released by hydrolysis of inactive prodrug)
Tmax (d-amphetamine)
~3.8 h fasted (4.7 h with high-fat meal)
Absorption
Rapid GI absorption; food prolongs Tmax by ~1 h but does not affect AUC or Cmax
Metabolism
Hydrolytic conversion by red blood cells (NOT by CYP enzymes)
Excretion
Renal (highly pH-dependent for d-amphetamine); not dialysable
Steady-State
No accumulation with once-daily dosing
Clinical Information
Drug Class
CNS stimulant; prodrug of dextroamphetamine; non-catecholamine sympathomimetic; DAT/NET reuptake inhibitor and releaser
Capsule Strengths
10, 20, 30, 40, 50, 60, 70 mg
Chewable Tablet Strengths
10, 20, 30, 40, 50, 60 mg
Maximum Daily Dose
70 mg/day (both ADHD and BED)
Renal Adjustment
Severe impairment: max 50 mg/day; ESRD: max 30 mg/day
Hepatic Adjustment
Not formally established
Pregnancy
Limited data; may cause fetal harm; registry available
Lactation
Breastfeeding NOT recommended
Schedule / Legal Status
DEA Schedule II (CII)
Boxed Warning
Yes — Abuse, Misuse, Addiction
Generic Available
Yes (generic lisdexamfetamine launched 2023)
Rx

Indications

IndicationApproved PopulationFirst ApprovalStatus
Attention-Deficit/Hyperactivity Disorder (ADHD)Adults and pediatric patients ≥6 years2007FDA Approved
Moderate to severe Binge Eating Disorder (BED)Adults onlyJanuary 2015FDA Approved

Lisdexamfetamine is a prodrug of dextroamphetamine that occupies a unique position among stimulants for two reasons. First, it is the only stimulant FDA-approved for binge eating disorder (approved January 2015) — no other amphetamine or methylphenidate product carries this indication, and lisdexamfetamine remains the only pharmacotherapy with FDA approval for moderate-to-severe BED in adults. Second, its prodrug pharmacology — requiring hydrolysis by red blood cells to release the active d-amphetamine — provides a smooth, predictable release pattern with reduced abuse liability via non-oral routes. In an FDA-cited intravenous abuse liability study, IV lisdexamfetamine produced lower subjective drug effects than equivalent doses of IV d-amphetamine in patients with a history of stimulant abuse. Despite this, lisdexamfetamine remains a Schedule II controlled substance with full abuse potential when taken orally at supratherapeutic doses.

For ADHD, lisdexamfetamine is one of the principal first-line stimulant options alongside methylphenidate-class agents and other amphetamine products. NICE (UK) positions lisdexamfetamine as a first-line stimulant option in adults. Because of its prodrug pharmacology and once-daily dosing, it is often considered for patients with concerns about diversion, college students, or anyone who would benefit from a tamper-resistant formulation.

Limitations of Use (FDA Label, revised 09/2025)

Pediatric <6 years: Not recommended. Children ages 4–5 had approximately 44% higher steady-state plasma exposure of dextroamphetamine compared to children 6–11 years at the same dose, with a higher incidence of adverse reactions including weight loss, decreased appetite, insomnia, irritability, and affect lability. This limitation was specifically updated in the September 2025 label revision.

Weight loss: VYVANSE is not indicated or recommended for weight loss. Use of other sympathomimetic drugs for weight loss has been associated with serious cardiovascular adverse events. Safety and effectiveness for the treatment of obesity have not been established.

BED in adolescents: Safety and effectiveness have not been established in patients with BED less than 18 years of age.

Off-Label and Specialist Uses

Treatment-resistant depression (augmentation): Used in some specialist psychiatric and palliative settings; evidence quality low. Lisdexamfetamine has been studied in augmentation trials for major depressive disorder but did not consistently meet primary endpoints in pivotal studies — no FDA approval for depression.

Cancer-related fatigue: Some palliative care use; evidence quality low. Methylphenidate has more evidence in this setting.

Cognitive symptoms in traumatic brain injury and post-stroke recovery: Limited evidence; methylphenidate generally preferred in rehabilitation settings.

Off-label use as a “study aid” or cognitive enhancer in non-ADHD individuals is not supported by clinical evidence and is associated with substantial misuse risk; this practice should be actively discouraged.

Dose

Dosing

Lisdexamfetamine is administered orally once daily in the morning with or without food. Afternoon doses must be avoided because of insomnia risk. Capsules can be swallowed whole or opened and the contents mixed with yogurt, water, or orange juice (mixture must be consumed immediately and not stored). Chewable tablets must be chewed thoroughly before swallowing. Capsules and chewable tablets are interchangeable on a unit-per-unit (mg-per-mg) basis. A single dose should not be divided, and patients should not take less than one capsule or chewable tablet per day.

By Indication and Population

Clinical ScenarioStarting DoseTitrationRecommended RangeMaximumNotes
ADHD — adults and pediatric (≥6 y)30 mg PO once daily (morning)10 mg or 20 mg increments at approximately weekly intervals30–70 mg/day70 mg/daySame dosing for adults and children ≥6 years per current FDA label
Take in morning; avoid afternoon doses
BED — adults only30 mg PO once daily (morning)20 mg increments at approximately weekly intervals50–70 mg/day (target range)70 mg/dayDiscontinue if binge eating does not improve
Not approved for BED in adolescents/children
Severe renal impairment (GFR 15 to <30 mL/min/1.73 m²)Same starting dose; titrate as tolerated50 mg/dayReduced clearance requires lower maximum
End-stage renal disease (GFR <15 mL/min/1.73 m²)Lower exposure tolerance30 mg/dayLisdexamfetamine and d-amphetamine are NOT dialysable
Switching between capsules and chewable tabletsSame total daily dose; mg-per-mg interchangeSame as currentNo re-titration needed; chewable tablets max 60 mg (no 70 mg chewable strength)
CYP2D6 inhibitor co-administration (e.g., paroxetine, fluoxetine, bupropion, quinidine, terbinafine)Initiate with lower dose; monitor for serotonin syndromeIndividualisedIncreases dextroamphetamine exposure
Alkalinising agent co-administration (e.g., sodium bicarbonate)Avoid concurrent use; counsel about OTC antacidsAdjust per labelIncreases amphetamine blood levels

Special Populations

  • Pediatric <6 years: Not recommended. The 09/2025 label update explicitly addressed higher exposure (~44% higher steady-state dextroamphetamine in 4–5 year-olds vs 6–11 year-olds at the same dose) and a higher incidence of adverse reactions including weight loss, decreased appetite, insomnia, irritability, and affect lability.
  • Pediatric BED <18 years: Safety and efficacy not established. The BED indication is restricted to adults.
  • Geriatric (≥65 years): Insufficient data in clinical trials to determine differential response. Start at the low end of the dosing range, considering greater frequency of decreased hepatic, renal, or cardiac function and concomitant disease.
  • Renal impairment: Severe (GFR 15 to <30 mL/min/1.73 m²) — maximum 50 mg/day. ESRD (GFR <15 mL/min/1.73 m²) — maximum 30 mg/day. Lisdexamfetamine and d-amphetamine are not dialysable.
  • Hepatic impairment: Not formally studied. Because the prodrug is hydrolysed by red blood cells (not by CYP enzymes) to release dextroamphetamine, hepatic dysfunction may have less impact on lisdexamfetamine exposure than for parent amphetamine products. Caution still warranted.
  • Pregnancy: Available data from published literature and postmarketing reports are not sufficient to inform a drug-associated risk. Animal reproduction studies showed no embryo-fetal effects with lisdexamfetamine in rats and rabbits during organogenesis at doses up to 5.5× and 33× the MRHD respectively. Amphetamines may cause vasoconstriction and decreased placental perfusion; uterine contractions may be stimulated. National Pregnancy Registry for Psychostimulants: 1-866-961-2388.
  • Lactation: Amphetamine is present in human milk at relative infant doses of 2–13.8% with milk-to-plasma ratios of 1.9–7.5. The FDA label specifically advises that breastfeeding is not recommended during VYVANSE treatment because of the potential for serious adverse reactions in nursing infants (cardiovascular reactions, BP/HR increases, growth suppression, peripheral vasculopathy).
Clinical Pearl — Why Once-Daily Only

Unlike Adderall, lisdexamfetamine does not have an immediate-release formulation, and the dosing label is exclusively once-daily morning. This is because the prodrug must be hydrolysed by red blood cells to release active d-amphetamine — a rate-limiting step that produces a smooth, predictable plasma curve. Per Ermer et al. (2016), the therapeutic action of lisdexamfetamine extends to at least 13 hours post-dose in children and 14 hours post-dose in adults. Splitting doses or attempting twice-daily dosing offers no PK advantage and increases insomnia risk. If a patient needs longer coverage than lisdexamfetamine provides, options include switching to triple-bead amphetamine (Mydayis, ≥13 years) — but this requires careful clinical judgement and increased monitoring.

Pre-Treatment Screening — Mandatory

Before initiating lisdexamfetamine, the FDA labelling requires: (1) careful cardiac history including family history of sudden cardiac death or ventricular arrhythmia, plus a physical examination; (2) family history and clinical evaluation for tics or Tourette’s syndrome; (3) screening for risk factors for a manic episode (history of depression, family history of bipolar disorder or suicide); (4) baseline blood pressure, heart rate, height and weight; and (5) assessment of risk for abuse, misuse, and addiction. Document each step in the medical record.

PK

Pharmacology

Mechanism of Action

Lisdexamfetamine is a prodrug of dextroamphetamine, formed by covalent linkage of the essential amino acid L-lysine to d-amphetamine via a peptide bond. The intact prodrug is pharmacologically inactive. After oral absorption, lisdexamfetamine is hydrolysed by red blood cells to release the active d-amphetamine and L-lysine. This hydrolysis is the rate-limiting step that controls the appearance of d-amphetamine in plasma — not gastric emptying, GI absorption, or cytochrome metabolism.

Once released, d-amphetamine exerts its pharmacological effects in the same way as parent amphetamine: blocking the reuptake of norepinephrine and dopamine into presynaptic neurons and increasing release of these monoamines into the extraneuronal space. Amphetamines also affect the serotonergic system, which underlies the labelled risk of serotonin syndrome. The FDA label states that the precise mode of therapeutic action in ADHD is not known.

Implications of prodrug pharmacology:

  • Smoother PK curve: The hydrolysis rate-limiting step produces a more gradual rise and fall in plasma d-amphetamine than direct oral d-amphetamine, with reduced peak-to-trough ratio and lower inter- and intra-individual variability in exposure (per Ermer et al., 2016).
  • Reduced abuse liability via non-oral routes: Crushing, snorting, or injecting lisdexamfetamine does not bypass the hydrolysis step. In an FDA-cited abuse liability study (Jasinski & Krishnan, 2009), IV administration of 50 mg lisdexamfetamine produced lower subjective “drug liking” effects than IV 20 mg d-amphetamine in patients with a history of stimulant abuse. This is one reason lisdexamfetamine is sometimes preferred in patients with diversion concerns. However, oral lisdexamfetamine at supratherapeutic doses can still produce significant abuse, and the boxed warning applies fully.
  • Limited drug-interaction profile via metabolism: Lisdexamfetamine is not metabolised by cytochrome P450 enzymes. The current FDA label explicitly states no dose adjustment is needed when co-administered with substrates of CYP1A2, CYP2D6, CYP2C19, or CYP3A4.
  • No food effect on AUC/Cmax: Food prolongs Tmax of d-amphetamine by approximately 1 hour (from 3.8 h fasted to 4.7 h after high-fat meal) but does not alter AUC or Cmax.
  • No accumulation at steady state with once-daily dosing.

Cardiovascular pharmacodynamics: amphetamines (including released d-amphetamine) produce small mean increases in heart rate (approximately 3–6 bpm) and blood pressure (approximately 2–4 mmHg) at therapeutic doses; some patients show larger increases.

ADME Profile

ParameterValueClinical Implication
AbsorptionLisdexamfetamine is rapidly absorbed from the GI tract; d-amphetamine Tmax ~3.8 h fasted, ~4.7 h after high-fat meal, ~4.2 h with yogurt; food prolongs Tmax by ~1 h but does not affect AUC or CmaxTake with or without food; capsule contents may be mixed with water, yogurt, or orange juice; chewable tablets must be chewed thoroughly
DistributionWide tissue distribution; d-amphetamine readily crosses blood-brain barrier; specific Vd not stated in current US PIOnset of clinical effects begins within approximately 1.5–2 hours of administration based on laboratory school study data
MetabolismLisdexamfetamine is hydrolysed by red blood cells to release d-amphetamine and L-lysine; substantial hydrolysis occurs even at low haematocrit (33% of normal) per in vitro data; lisdexamfetamine is NOT metabolised by cytochrome P450 enzymes; the released d-amphetamine then undergoes hepatic oxidation (with partial CYP2D6 contribution) and conjugationFew clinically meaningful drug interactions via metabolism; no dose adjustment needed for CYP1A2, CYP2D6, CYP2C19, or CYP3A4 substrates
EliminationRenal excretion of d-amphetamine is highly pH-dependent (pKa 9.9 — alkaline urine reduces elimination, acidic urine increases it); elimination half-life of d-amphetamine ~10 hours (consistent with parent amphetamine PK); no accumulation with once-daily dosing; lisdexamfetamine and d-amphetamine are not dialysableUrinary alkalinising agents (e.g., sodium bicarbonate) and acidifying agents (e.g., ascorbic acid) significantly alter exposure; severe renal impairment requires dose reduction; ESRD requires further reduction

Clinical duration: A single morning dose of lisdexamfetamine provides therapeutic action up to approximately 13 hours in children and 14 hours in adults (Ermer et al., 2016) — generally longer than Adderall XR’s typical coverage and shorter than Mydayis.

SE

Side Effects

Lisdexamfetamine has the typical stimulant adverse-effect profile dominated by appetite suppression, insomnia, dry mouth, weight loss, and small cardiovascular changes. The adverse-event profile is broadly similar to that of mixed amphetamine salts. All quantitative incidence data below are taken directly from the Vyvanse FDA prescribing information clinical trial tables (Tables 1, 2, 3, 4; revised 09/2025).

≥10% Very Common Adverse Effects
Adverse EffectPopulation / IncidenceClinical Note
Decreased appetite39% (children 6–12), 34% (adolescents 13–17), 27% (adults ADHD)
vs 4%, 3%, 2% placebo respectively
Most common adverse effect; dose-related; encourage front-loaded breakfast and calorie-dense evening intake
Dry mouth26% (adults ADHD), 36% (adults BED)
vs 3%, 7% placebo respectively; 5% in children 6–12 (vs 0% placebo)
Most prominent in adults; encourage hydration; sugar-free gum or saliva substitutes; dental review for prolonged use
Insomnia22% (children 6–12), 13% (adolescents 13–17), 27% (adults ADHD), 20% (adults BED)
vs 3%, 4%, 8%, 8% placebo respectively
Avoid late dosing; assess sleep hygiene; if persistent consider lower dose
Upper abdominal pain (children 6–12)12% (children) vs 6% placeboUsually mild and transient; take with food
Irritability (children 6–12)10% (children) vs 0% placeboOften dose-related; consider dose reduction; evaluate for end-of-dose rebound
1–10% Common Adverse Effects
Adverse EffectPopulation / IncidenceClinical Note
Vomiting (children 6–12)9% vs 4% placeboTake with food; usually transient
Weight decreased9% (children 6–12), 9% (adolescents 13–17), 3% (adults ADHD), 4% (adults BED)
vs 1%, 0%, 0%, 0% placebo respectively
Plot growth at every visit in children; dose-related — see weight loss data below
Nausea6% (children 6–12), 7% (adults ADHD)
vs 3%, 0% placebo
Take with food
Anxiety (adults)6% (adults ADHD), 5% (adults BED)
vs 0%, 1% placebo
Often dose-related; can lead to discontinuation
Diarrhea (adults)7% (adults ADHD), 4% (adults BED)
vs 0%, 2% placebo
Generally mild; assess hydration
Increased heart rate (adults)7% (adults BED), 2% (adults ADHD)
vs 1%, 0% placebo
Mean HR increase 3–6 bpm; some patients larger; monitor pulse at every visit
Constipation (adults BED)6% (adults BED) vs 1% placeboNotable for BED population; encourage fluids and fibre
Feeling jittery (adults)6% (adults BED), 4% (adults ADHD)
vs 1%, 0% placebo
Often dose-related
Dizziness (children 6–12)5% (children) vs 0% placeboCaution with active play; evaluate for hypotension
Anorexia (distinguished from “decreased appetite”)2% (children), 2% (adolescents), 5% (adults ADHD)
vs 0%, 0%, 0% placebo
Dose-related; manage with calorie-dense foods at peak appetite times
Hyperhidrosis (adults)4% (adults BED), 3% (adults ADHD)
vs 0%, 0% placebo
Sympathomimetic effect; usually tolerable
Affect lability (children 6–12)3% (children) vs 0% placeboHigher rates seen in 4–5 year-olds (off-label) — one reason for the <6 years recommendation
Rash (children 6–12)3% (children) vs 0% placeboUsually mild; evaluate for serious cutaneous reactions if extensive
Tic (children 6–12)2% (children) vs 0% placeboPre-existing tics or family history are warning signs; monitor closely; discontinue if worsening
Tremor (adolescents, adults)2% (adolescents), 2% (adults ADHD)
vs 0%, 0% placebo
Sympathomimetic; usually tolerable
Palpitations (adolescents, adults)2% (adolescents), 2% (adults ADHD)
vs 1%, 0% placebo
Investigate if persistent; ECG if suspected arrhythmia
Erectile dysfunction (adult males)2.6% (adult males) vs 0% placeboSometimes dose-limiting; consider dose reduction
Decreased libido (adults)1.4% (adults) vs 0% placeboOften improves with dose reduction
Increased blood pressure3% (adults ADHD)
vs 0% placebo; mean rise 2–4 mmHg overall
Some patients larger increases; routine monitoring captures this early
Serious Serious / Labelled Warning-Level Adverse Effects
Adverse EffectEstimated FrequencyTypical OnsetRequired Action
Substance use disorder, dependence, overdose, death (boxed warning)Risk variable; markedly elevated with non-medical useAny time during therapy; risk rises with high-dose oral usePre-treatment risk screen; safe storage; monitor throughout treatment; consider gradual taper after prolonged use; prodrug pharmacology reduces but does not eliminate abuse risk
Sudden death, stroke, myocardial infarction (in patients with serious cardiac disease)Rare
post-marketing reports at therapeutic ADHD doses
Any time; pediatric cases reported in those with structural heart diseaseAvoid in known structural cardiac abnormality, cardiomyopathy, serious arrhythmia, or coronary disease; investigate exertional chest pain, syncope, arrhythmia
New psychotic or manic symptoms (hallucinations, delusional thinking, mania)~0.1%
pooled placebo-controlled trials in patients without prior psychotic history
Days to weeks after initiation or dose increaseConsider discontinuation; evaluate for underlying bipolar disorder; do not restart without specialist input
Serotonin syndrome (with serotonergic agents or CYP2D6 inhibitors)Rare; labelled warning (Section 5.7 in current PI)Hours to days after combining with serotonergic drug or starting CYP2D6 inhibitorDiscontinue both agents immediately; supportive care; CYP2D6 inhibitors increase exposure to released d-amphetamine
Long-term suppression of growth (pediatric)Mean weight change −0.9 to −2.5 lbs (children 6–12, doses 30/50/70 mg) and −2.7 to −4.8 lbs (adolescents)
vs +1 lb / +2 lbs placebo gain in 4-week trials; 12-month percentile change −13.4 in children
Weight changes detectable within 4 weeks; cumulative over months–yearsPlot height/weight at every visit; if not tracking expected curve, interrupt treatment or consider drug holidays
Peripheral vasculopathy / Raynaud’s phenomenonUncommon
post-marketing; can include digital ulceration / soft-tissue breakdown
Any time during treatment; intermittent symptomsExamine fingers/toes at follow-up; refer to rheumatology if signs of vasculopathy; reduce dose or discontinue if symptomatic
Severe cutaneous reactions (Stevens-Johnson syndrome)Very rare
post-marketing reports
Any time; usually within first weeks of treatmentImmediate discontinuation; emergency dermatology evaluation; permanent contraindication to amphetamines
Hypersensitivity (anaphylaxis, angioedema, urticaria)RareMinutes to days after dosingPermanent discontinuation; emergency care if airway involved; document allergy
Cardiomyopathy (chronic use)Isolated reports
post-marketing
Long-term cumulativeInvestigate any new exertional symptoms or echocardiographic changes; consider discontinuation
Eosinophilic hepatitisRare
post-marketing reports
Any timeDiscontinue if liver enzyme abnormalities and eosinophilia develop; specialist evaluation
Priapism (frequent or prolonged erections)Rare
listed in post-marketing experience
After some time on therapy; may occur during dose changesImmediate medical attention — irreversible damage possible without prompt urology evaluation
SeizuresRare
post-marketing; amphetamines may lower seizure threshold
Any time; risk highest in those with prior seizure historyDiscontinue if seizure occurs; use cautiously in seizure disorder
RhabdomyolysisRare
post-marketing; especially with overdose or strenuous exertion
AcuteDiscontinue; emergency care with hydration and CK monitoring
Discontinuation Treatment Discontinuation Rates (Vyvanse controlled trials)
Children (Ages 6–12, ADHD, 4-week)
8% vs 0% placebo
Reasons (≥1% and 2× placebo): ECG voltage criteria for ventricular hypertrophy, tic, vomiting, psychomotor hyperactivity, insomnia, decreased appetite, rash (each at 1%, n=2/218).
Adolescents (Ages 13–17, ADHD, 4-week)
3% vs 1% placebo
Reasons (≥1% and 2× placebo): decreased appetite (1%), insomnia (1%).
Adults (ADHD, 4-week)
6% vs 2% placebo
Top reasons (≥1% in Vyvanse arm): insomnia (2%), tachycardia (1%), irritability (1%), hypertension (1%), headache (1%), anxiety (1%), dyspnea (1%).
Adults (BED, 12-week)
5.1% vs 2.4% placebo
No single AE led to discontinuation in ≥1% of Vyvanse-treated patients.

Weight Loss Data — by Dose

PopulationDose 30 mgDose 50 mgDose 70 mgPlacebo
Children ages 6–12 (4-week)−0.9 lbs−1.9 lbs−2.5 lbs+1.0 lb
Adolescents ages 13–17 (4-week)−2.7 lbs−4.3 lbs−4.8 lbs+2.0 lbs
Adults ADHD (4-week, final dose)−2.8 lbs−3.1 lbs−4.3 lbs+0.5 lbs
Children 6–12 (12-month follow-up)Mean change in age- and sex-normalized weight percentile: −13.4 (from 60.9 to 47.2 over 12 months)
Clinical Pearl — Discontinuation Rate Comparisons

The 6% adult ADHD discontinuation rate in the Vyvanse trial appears lower than the 12% rate reported in the Adderall XR adult ADHD trial (4-week, doses up to 60 mg). However, cross-trial comparisons are not straightforward because of different dose ranges, study designs, and patient populations. The lower observed rate may partly reflect the smoother PK profile produced by lisdexamfetamine’s prodrug release. Clinically, lisdexamfetamine is often perceived to be better tolerated than IR amphetamine, particularly in adults sensitive to peak-related anxiety or jitteriness.

Int

Drug Interactions

Lisdexamfetamine has a more limited drug-interaction profile than parent amphetamine because the prodrug itself is hydrolysed by red blood cells rather than metabolised by cytochrome enzymes. The current Vyvanse PI Table 5 lists six categories of clinically important interactions: monoamine oxidase inhibitors, serotonergic drugs, CYP2D6 inhibitors, alkalinising agents, acidifying agents, and tricyclic antidepressants. Notably, the FDA label specifically lists categories of drugs with no clinically important interactions: guanfacine, venlafaxine, omeprazole, and CYP1A2/2D6/2C19/3A4 substrates — a useful clinical fact when managing complex polypharmacy.

Major Monoamine oxidase inhibitors (MAOIs) — including linezolid and IV methylene blue
MechanismMAOI antidepressants slow amphetamine metabolism, increasing amphetamine effect on monoamine release
EffectHypertensive crisis with headaches and other signs; toxic neurological effects and malignant hyperpyrexia can occur, sometimes fatal
ManagementContraindicated; allow 14-day washout after MAOI discontinuation before initiating Vyvanse (and vice versa)
FDA PI Table 5 · Contraindication
Major Serotonergic drugs (SSRIs, SNRIs, triptans, TCAs, fentanyl, lithium, tramadol, tryptophan, buspirone, St. John’s Wort)
MechanismAdditive serotonergic activity; amphetamines have direct serotonergic effects
EffectSerotonin syndrome — mental status changes, autonomic instability, neuromuscular signs (hyperreflexia, clonus, rigidity), seizures, GI symptoms
ManagementInitiate Vyvanse at lower dose; monitor closely during initiation and dose increases; counsel on serotonin syndrome symptoms; if syndrome occurs, discontinue both agents and provide supportive care
FDA PI Table 5 (Warning 5.7)
Major CYP2D6 inhibitors (paroxetine, fluoxetine, bupropion, quinidine, terbinafine)
MechanismCYP2D6 partially metabolises released d-amphetamine — inhibition raises exposure
EffectIncreased dextroamphetamine plasma exposure; increased risk of serotonin syndrome and cardiovascular adverse effects
ManagementInitiate Vyvanse at lower dose; monitor for serotonin syndrome and cardiovascular signs during initiation and dose increase; if syndrome occurs, discontinue both agents
FDA PI Table 5
Moderate Alkalinising agents (sodium bicarbonate, antacids, urinary alkalinisers like potassium citrate)
MechanismAlkaline urine pH reduces ionisation of amphetamine, reducing renal excretion
EffectIncreased amphetamine blood levels; potentiated effects and cardiovascular risk
ManagementAvoid concurrent use; counsel patients about OTC antacids; use H2 blockers or PPIs instead when an antacid effect is needed
FDA PI Table 5
Moderate Acidifying agents (ascorbic acid / vitamin C, fruit juices)
MechanismAcidic urine pH increases amphetamine ionisation, increasing renal elimination
EffectLower amphetamine blood levels; reduced clinical efficacy
ManagementIncrease Vyvanse dose based on clinical response; counsel patients that high-dose vitamin C supplementation can blunt effect
FDA PI Table 5
Moderate Tricyclic antidepressants (imipramine, amitriptyline, desipramine)
MechanismPharmacodynamic — striking, sustained increases in d-amphetamine brain concentration; combined cardiovascular effects
EffectEnhanced cardiovascular effects (BP, HR), increased CNS stimulation; serotonin syndrome also possible (TCAs are serotonergic)
ManagementMonitor frequently; consider alternative antidepressant or non-stimulant ADHD agent
FDA PI Table 5
Caution Antihypertensives
MechanismAmphetamine raises BP and may antagonise antihypertensive effects
EffectPossible loss of BP control
ManagementMonitor BP; titrate antihypertensive dose as needed
Class effect
Caution Other CNS stimulants / sympathomimetics (decongestants, caffeine)
MechanismAdditive sympathomimetic activity
EffectTachycardia, hypertension, anxiety, insomnia
ManagementAvoid OTC decongestants; moderate caffeine intake; counsel patients explicitly
Class effect
Clinically Useful “No Interaction” List (per FDA PI Section 7.2)

The current Vyvanse label specifically states that no dose adjustment of Vyvanse is necessary when co-administered with: guanfacine, venlafaxine, or omeprazole. In addition, no dose adjustment is needed for substrates of the major CYP enzymes — including theophylline, duloxetine, melatonin (CYP1A2); atomoxetine, desipramine, venlafaxine (CYP2D6); omeprazole, lansoprazole, clobazam (CYP2C19); midazolam, pimozide, simvastatin (CYP3A4). This is because lisdexamfetamine itself is hydrolysed by red blood cells, not by CYP enzymes, and the released d-amphetamine produces only minor inhibition of CYP enzymes at therapeutic doses. This is a clinically useful difference from many other CNS-active medications.

Mon

Monitoring

Monitoring lisdexamfetamine therapy is structured around five pillars: cardiovascular vital signs, growth (in children), psychiatric tolerability, abuse/misuse surveillance, and (for BED) clinical response — discontinuing if binge eating does not improve. The goal is early detection of dose-related side effects and prevention of diversion or misuse.

  • Blood pressure and heart rate Baseline, then at every dose change and every routine visit (≥3-monthly)
    Routine
    Mean expected rise: BP 2–4 mmHg, HR 3–6 bpm. Sustained BP >130/80 in adults or >95th centile in children, or HR >100 bpm sustained at rest, warrants dose reduction or alternative therapy.
  • Height and weight (pediatric) Every 3–6 months; plot on growth chart
    Routine
    Pediatric trial data show dose-related weight loss within 4 weeks, and 12-month follow-up shows mean weight percentile decrease of 13.4 in consistently medicated children. Watch for crossing percentiles downward. Consider drug holidays or treatment interruption if growth deviates.
  • Psychiatric symptom screen Every visit
    Routine
    Screen for new mania, psychosis, agitation, suicidal ideation, mood lability, and worsening of pre-existing psychiatric conditions. Document family history of bipolar disorder at baseline.
  • Abuse and diversion screening At each refill; PDMP query as required by state
    Routine
    Although prodrug pharmacology reduces non-oral abuse liability, oral lisdexamfetamine remains highly abusable. Assess for early refill requests, lost prescriptions, multiple-prescriber pattern, and concerning behaviour. Confirm safe storage at home.
  • BED response (BED indication only) At each visit; consider weekly binge-day count
    Routine
    FDA label specifically recommends discontinuing Vyvanse if binge eating does not improve. Combine with cognitive behavioural therapy where possible.
  • Sleep and appetite Every visit
    Routine
    Specific questioning about sleep onset latency, total sleep time, and breakfast/evening intake. These data drive dose adjustment decisions.
  • Tic/Tourette’s surveillance Baseline and every visit
    Routine
    New or worsening motor/verbal tics may emerge; assess at each visit; discontinuation considered if clinically significant.
  • Serotonin syndrome surveillance When combined with any serotonergic agent or CYP2D6 inhibitor
    Trigger-based
    Counsel about agitation, hyperthermia, clonus, hyperreflexia, autonomic instability. Initiate Vyvanse at a lower dose when adding to existing serotonergic regimen.
  • Renal function Annually or as clinically indicated
    Routine
    Vyvanse requires dose reduction in severe renal impairment (max 50 mg/day) and ESRD (max 30 mg/day). Re-evaluate eGFR if comorbidities arise.
  • Digital examination (Raynaud’s screen) Baseline, then on patient report
    Trigger-based
    Examine fingers and toes for colour change, ulceration, or coolness. Refer to rheumatology if signs develop. Discontinue or switch agent if vasculopathy progresses.
  • ECG / cardiology referral Only when cardiac risk factors or symptoms identified
    Trigger-based
    Routine baseline ECG is not mandated by FDA labelling but is reasonable when family history suggests inherited arrhythmia (e.g., long QT, HCM) or in symptomatic patients. Investigate exertional chest pain, syncope, or palpitations promptly.
  • Treatment continuation review Annually
    Routine
    Periodically reassess ongoing need for stimulant therapy. For BED, the label is explicit: discontinue if binge eating does not improve. Consider planned treatment interruptions or holidays where clinically reasonable.
Key Clinical Action

The single highest-yield monitoring intervention is documenting blood pressure, heart rate, height and weight at every visit, plotted on a growth chart for pediatric patients. Combined with a brief psychiatric, sleep, appetite, and abuse-risk screen — and, for BED, an objective measure of binge frequency — this five-minute review captures the major safety and efficacy signals that the FDA boxed warning and labelled precautions all centre on.

CI

Contraindications & Cautions

Absolute Contraindications

  • Concomitant treatment with monoamine oxidase inhibitors (MAOIs), or use within 14 days of MAOI discontinuation — this includes the antibiotic linezolid and intravenous methylene blue. Risk of hypertensive crisis, stroke, MI, aortic dissection, and death.
  • Known hypersensitivity to amphetamine products or other components of Vyvanse — including prior anaphylaxis, angioedema, urticaria, or Stevens-Johnson syndrome (all reported in postmarketing experience).

Relative Contraindications (Specialist Input Recommended)

  • Known structural cardiac abnormalities (e.g., hypertrophic cardiomyopathy), cardiomyopathy, serious cardiac arrhythmias, coronary artery disease, or other serious cardiac disease — sudden death has been reported at therapeutic ADHD doses; cardiology assessment required before any consideration of use.
  • Active or recent substance use disorder — although prodrug pharmacology reduces non-oral abuse liability, oral lisdexamfetamine has full Schedule II abuse potential. Use only under specialist supervision; non-stimulant alternatives (atomoxetine, viloxazine, guanfacine ER, clonidine ER) should be considered first.
  • Pre-existing psychotic disorder — symptoms may be exacerbated; co-management with psychiatry essential.
  • Bipolar disorder, especially without mood stabiliser cover — risk of mania induction; do not initiate without psychiatric input and adequate mood stabilisation.
  • Pediatric <6 years — not recommended per current FDA label (revised 09/2025). Children 4–5 years had ~44% higher dextroamphetamine exposure and higher rates of weight loss, decreased appetite, insomnia, irritability, and affect lability.
  • Pediatric <18 years for BED indication — not approved; safety and efficacy not established.
  • Pregnancy — limited human data; amphetamines cause vasoconstriction and may decrease placental perfusion; uterine contractions can be stimulated; use only when benefits clearly outweigh risks. Encourage National Pregnancy Registry for Psychostimulants enrolment (1-866-961-2388).
  • Lactation — the FDA label specifically advises against breastfeeding during Vyvanse therapy. RID 2–13.8% of maternal weight-adjusted dose.
  • Severe renal impairment and ESRD — dose reductions required (max 50 mg/day in severe impairment, 30 mg/day in ESRD); not dialysable.
  • Pre-existing peripheral vasculopathy or Raynaud’s phenomenon with ischaemic complications — risk of digital ulceration; specialist input recommended before initiation.

Use with Caution

  • Pre-existing hypertension or tachyarrhythmia — small but real BP and HR increases; ensure stable control before initiation; monitor closely.
  • History of motor or verbal tics, or family history of Tourette’s syndrome — may emerge or worsen; assess at every visit.
  • History of seizure disorder or EEG abnormalities — amphetamines may lower the seizure threshold; ensure good baseline seizure control before initiation; discontinue if seizure occurs.
  • Concurrent use of serotonergic medications or CYP2D6 inhibitors — increased risk of serotonin syndrome; initiate at lower doses with monitoring.
  • Concurrent acidifying or alkalinising agents — may significantly alter dextroamphetamine exposure; counsel about OTC antacids and high-dose vitamin C.
  • Pediatric patients on year-round stimulant therapy — monitor growth; consider drug holidays.
  • Older adults (≥65 years) — limited safety data; cardiovascular comorbidity is more common; start at the lowest available dose.
  • Patients with depression, anxiety, or suicidal ideation — mood worsening or new psychiatric symptoms have been reported; close monitoring and integrated mental health management required.
  • BED patients without response after adequate trial — the FDA label explicitly directs discontinuation if binge eating does not improve.
FDA Boxed Warning Abuse, Misuse, and Addiction

Vyvanse has a high potential for abuse and misuse, which can lead to the development of a substance use disorder, including addiction. Misuse and abuse of CNS stimulants, including Vyvanse, can result in overdose and death. Risk is increased with higher doses or with unapproved methods of administration such as snorting or injection.

Pre-treatment: Assess each patient’s individual risk for abuse, misuse, and addiction before prescribing. Educate patients and their families about these risks, the importance of safe (preferably locked) storage, and proper disposal of unused medication.

During treatment: Reassess each patient’s risk at each visit and frequently monitor for signs and symptoms of abuse, misuse, and addiction. Maintain careful prescription records and check the state Prescription Drug Monitoring Program where available. Counsel patients explicitly: never share medication, never alter the route of administration, and never increase the dose without prescriber agreement.

Editorial note on prodrug pharmacology: Although the FDA boxed warning text does not address it specifically, lisdexamfetamine’s prodrug structure produces less subjective drug effect when administered IV than equivalent doses of d-amphetamine (per Jasinski & Krishnan, 2009). This reduces but does not eliminate abuse potential. Oral abuse at supratherapeutic doses remains a significant risk and the boxed warning applies fully.

Discontinuation: Vyvanse may produce physical dependence after prolonged use. Withdrawal symptoms can include dysphoric mood, depression, fatigue, vivid unpleasant dreams, insomnia or hypersomnia, increased appetite, and psychomotor changes. Consider gradual taper rather than abrupt cessation after long-term use.

Pt

Patient Counselling

Purpose of Therapy

Vyvanse is a stimulant prescription medicine used to treat attention-deficit/hyperactivity disorder (ADHD) in adults and children aged 6 and older, and moderate-to-severe binge eating disorder (BED) in adults. In ADHD, this medicine can help improve attention, reduce impulsivity, and reduce hyperactivity. In BED, it can reduce the number of binge eating days. Vyvanse works best when combined with non-medication strategies — for ADHD, that means behavioural strategies, school or workplace accommodations, sleep hygiene, exercise, and (where appropriate) parent or family training. For BED, cognitive behavioural therapy and structured eating support remain important. The medicine is not a cure for either condition; it manages symptoms while it is in your system. Vyvanse is not approved for, and should never be used for, weight loss.

How to Take

Vyvanse is taken once a day in the morning, with or without food. Do not take it in the afternoon or evening — it can cause trouble sleeping. Capsules can be swallowed whole, or you can open the capsule and stir the contents into a small amount of yogurt, water, or orange juice. If you do this, drink or eat the whole mixture right away — do not save it for later. Chewable tablets must be chewed thoroughly before swallowing. Do not split a dose. Do not take less than one whole capsule or chewable tablet per day.

Safe Storage and Sharing
Tell patient This medicine is a federally controlled substance because it can be misused. Store it in a safe place — ideally locked — out of reach of children, teenagers, and visitors. Never share your medicine with anyone, even someone with the same condition. Sharing or selling it is illegal and can cause serious harm to others.
Call prescriber If any pills are missing or stolen, if your supply is running out faster than expected, or if you feel a strong urge to take more than the prescribed dose.
Heart-Related Symptoms
Tell patient Vyvanse slightly raises heart rate and blood pressure. In people with heart problems, even normal doses have rarely caused sudden serious problems including sudden death. Tell your prescriber about any history of heart problems in you or your family.
Call prescriber Seek immediate medical attention for chest pain on exertion, fainting, severe palpitations, sudden shortness of breath, or signs of stroke.
Mood and Mental Health Symptoms
Tell patient Stimulants can cause new psychiatric symptoms even in people without a history of these conditions, including hearing or seeing things that are not real, feeling unusually elated or “high,” severe agitation, or worsening anxiety or depression.
Call prescriber Right away for any new or worsening psychiatric symptoms, particularly hallucinations, delusions, manic feelings, or thoughts of self-harm.
Antidepressants and Pain Medicines (Serotonin Syndrome)
Tell patient Vyvanse can interact with many antidepressants and certain pain medicines (including tramadol and fentanyl) to cause a rare but serious condition called serotonin syndrome. Tell every prescriber and pharmacist you see that you are taking Vyvanse before they prescribe a new antidepressant or pain medicine.
Call prescriber Right away or seek emergency care for agitation, fast heart rate, sweating, fever, muscle twitching or stiffness, or confusion shortly after starting or increasing one of these medicines.
Appetite, Weight, and Growth (Children)
Tell patient / parent Decreased appetite is the most common effect of Vyvanse. Practical measures: a substantial breakfast before the morning dose, calorie-dense snacks throughout the day, and a satisfying evening meal when appetite returns. In children, height and weight will be tracked at every visit.
Call prescriber If the child is not gaining weight as expected, dropping percentile lines on the growth chart, or if appetite is so reduced that meals are being skipped consistently.
Sleep
Tell patient Difficulty falling asleep is one of the most common effects, especially in adults and especially when starting or increasing the dose. Always take Vyvanse first thing in the morning. Do not take it in the afternoon. Maintain a regular sleep routine and limit screen time before bed.
Call prescriber If insomnia persists despite morning dosing, or if it is significantly affecting daytime functioning.
Cold or Discoloured Fingers / Toes (Raynaud’s)
Tell patient Some people develop circulation problems in the fingers or toes while taking stimulants. The fingers or toes can feel numb, cool, or painful, and may change colour from pale to blue to red. Rarely, ulcers or wounds can appear on the fingers or toes.
Call prescriber Promptly for any colour changes, persistent numbness, painful fingers/toes, or any unexplained wounds on the digits.
Prolonged or Painful Erections (Priapism)
Tell patient Vyvanse can rarely cause painful, prolonged erections. This can be a medical emergency because of the risk of permanent damage. It can occur after months of treatment or after a dose increase.
Call prescriber Seek emergency care immediately for any erection lasting longer than 4 hours or any abnormally painful erection.
Antacids, Vitamin C, and Other OTC Medicines
Tell patient Some over-the-counter medicines can change how Vyvanse works. Antacids and sodium bicarbonate can make the level too high; high-dose vitamin C and acidic drinks can make the level too low. Tell your pharmacist that you take Vyvanse before buying antacids, decongestants, or large vitamin doses. Avoid combining with extra caffeine or other stimulants.
Call prescriber Before starting any new prescription, OTC medicine, or herbal supplement.
Pregnancy and Breastfeeding
Tell patient If you are pregnant, planning a pregnancy, or breastfeeding, tell your prescriber. Vyvanse passes into breast milk, and the FDA label specifically advises against breastfeeding during treatment. The National Pregnancy Registry for Psychostimulants (1-866-961-2388) collects information that helps future patients — please consider enrolling.
Call prescriber As soon as pregnancy is suspected or confirmed, or before starting breastfeeding, to discuss whether to continue, adjust, or change therapy.
For BED Patients — Tracking Response
Tell patient If you are taking Vyvanse for binge eating disorder, your prescriber will check whether the medicine is reducing your binge eating. Keep a simple diary of binge episodes (date, type, approximate duration). The medicine should be discontinued if binge eating does not improve. Vyvanse is not approved for weight loss and should not be used for that purpose.
Call prescriber If binge eating has not improved after several weeks at the target dose, or if you find yourself using Vyvanse for weight loss rather than binge control.
Stopping Treatment
Tell patient If you have been taking Vyvanse for a long time, do not stop suddenly without speaking to your prescriber. Some people experience low mood, fatigue, increased appetite, vivid dreams, or sleep changes for several days after stopping. Returning ADHD or binge eating symptoms are common and expected when treatment ends.
Call prescriber Before stopping, missing several doses, or running out, so a plan can be made for tapering or transitioning to another therapy.
Ref

Sources

Regulatory (Prescribing Information)
  1. U.S. Food and Drug Administration. VYVANSE (lisdexamfetamine dimesylate) capsules and chewable tablets, CII — Prescribing Information. Takeda Pharmaceuticals. Revised September 2025. Reference ID 5664030. accessdata.fda.gov Most recent FDA-approved label for Vyvanse; primary source for all quantitative adverse-event incidence data, drug interaction Table 5, dosing recommendations, weight loss data, and labelled warnings used in this monograph. Recent major changes (09/2025): Indications and Usage (1), Warnings and Precautions (5.5).
  2. U.S. Food and Drug Administration. FDA expands uses of Vyvanse to treat binge-eating disorder. FDA News Release, January 30, 2015. fda.gov Press release accompanying the January 2015 FDA approval of Vyvanse for moderate-to-severe binge eating disorder in adults — the first and only FDA-approved pharmacotherapy for BED.
  3. U.S. Food and Drug Administration. Drug Safety Communication: Risk of weight loss in children younger than 6 years taking extended-release stimulants for ADHD. June 30, 2025. fda.gov Recent FDA safety communication informing labelling updates for extended-release stimulants in patients younger than 6 years; relevant context for the 09/2025 Vyvanse limitation of use in children <6 years.
Key Clinical Trials
  1. McElroy SL, Hudson JI, Mitchell JE, et al. Efficacy and safety of lisdexamfetamine for treatment of adults with moderate to severe binge-eating disorder: a randomized clinical trial. JAMA Psychiatry. 2015;72(3):235–246. doi: 10.1001/jamapsychiatry.2014.2162 Pivotal phase 3 trial of lisdexamfetamine in adult BED; supported FDA approval. Demonstrated significant reduction in binge eating days/week vs placebo.
  2. McElroy SL, Hudson J, Ferreira-Cornwell MC, Radewonuk J, Whitaker T, Gasior M. Lisdexamfetamine dimesylate for adults with moderate to severe binge eating disorder: results of two pivotal phase 3 randomized controlled trials. Neuropsychopharmacology. 2016;41(5):1251–1260. doi: 10.1038/npp.2015.275 Pooled analysis of the two pivotal 12-week BED trials at lisdexamfetamine 50 and 70 mg/day; both studies favoured LDX over placebo on the primary endpoint.
  3. Hudson JI, McElroy SL, Ferreira-Cornwell MC, Radewonuk J, Gasior M. Efficacy of lisdexamfetamine in adults with moderate to severe binge-eating disorder: a randomized clinical trial. JAMA Psychiatry. 2017;74(9):903–910. doi: 10.1001/jamapsychiatry.2017.1889 Long-term randomized withdrawal study showing lisdexamfetamine markedly reduced relapse risk in BED.
  4. Cortese S, Adamo N, Del Giovane C, et al. Comparative efficacy and tolerability of medications for attention-deficit hyperactivity disorder in children, adolescents, and adults: a systematic review and network meta-analysis. Lancet Psychiatry. 2018;5(9):727–738. doi: 10.1016/S2215-0366(18)30269-4 Network meta-analysis comparing ADHD medications across age groups; methylphenidate is favoured in children/adolescents while amphetamines (including lisdexamfetamine) are favoured in adults on the efficacy/tolerability balance.
  5. Cooper WO, Habel LA, Sox CM, et al. ADHD drugs and serious cardiovascular events in children and young adults. N Engl J Med. 2011;365(20):1896–1904. doi: 10.1056/NEJMoa1110212 Large cohort study (~1.2 million patients aged 2–24) showing no significant increase in serious cardiovascular events with stimulant ADHD medications including amphetamines.
Guidelines
  1. Wolraich ML, Hagan JF Jr, Allan C, et al; Subcommittee on Children and Adolescents with Attention-Deficit/Hyperactive Disorder. Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents. Pediatrics. 2019;144(4):e20192528. doi: 10.1542/peds.2019-2528 American Academy of Pediatrics guideline; supports stimulants (methylphenidate or amphetamines, including lisdexamfetamine) as first-line pharmacotherapy for ADHD in children ≥6 years.
  2. National Institute for Health and Care Excellence (NICE). Attention deficit hyperactivity disorder: diagnosis and management. NICE guideline NG87. nice.org.uk/guidance/ng87 UK national guideline; positions lisdexamfetamine and methylphenidate as first-line stimulant options in adults with ADHD.
Mechanistic / Pharmacology
  1. Ermer JC, Pennick M, Frick G. Lisdexamfetamine dimesylate: prodrug delivery, amphetamine exposure and duration of efficacy. Clin Drug Investig. 2016;36(5):341–356. doi: 10.1007/s40261-015-0354-y Detailed open-access review of lisdexamfetamine’s prodrug PK/PD profile, including red blood cell hydrolysis kinetics and the relationship between exposure and clinical duration of effect (up to 13 hours in children, 14 hours in adults).
  2. Heal DJ, Smith SL, Gosden J, Nutt DJ. Amphetamine, past and present — a pharmacological and clinical perspective. J Psychopharmacol. 2013;27(6):479–496. doi: 10.1177/0269881113482532 Comprehensive review of amphetamine pharmacology including detailed coverage of lisdexamfetamine’s prodrug pharmacology and reduced abuse liability profile.
  3. Jasinski DR, Krishnan S. Human pharmacology of intravenous lisdexamfetamine dimesylate: abuse liability in adult stimulant abusers. J Psychopharmacol. 2009;23(4):410–418. doi: 10.1177/0269881108093841 FDA-cited IV abuse liability study showing IV lisdexamfetamine produces lower subjective drug effects than equivalent doses of IV d-amphetamine in stimulant abusers.
  4. Castells X, Blanco-Silvente L, Cunill R. Amphetamines for attention deficit hyperactivity disorder (ADHD) in adults. Cochrane Database Syst Rev. 2018;8(8):CD007813. doi: 10.1002/14651858.CD007813.pub3 Cochrane systematic review including lisdexamfetamine; demonstrated short-term efficacy in adult ADHD with low to very low certainty of evidence.
Special Populations
  1. Huybrechts KF, Bröms G, Christensen LB, et al. Association between methylphenidate and amphetamine use in pregnancy and risk of congenital malformations. JAMA Psychiatry. 2018;75(2):167–175. doi: 10.1001/jamapsychiatry.2017.3644 Large multinational cohort study evaluating birth defect risk with stimulant exposure during pregnancy.
  2. Heo YA, Duggan ST. Lisdexamfetamine: a review in binge eating disorder. CNS Drugs. 2017;31(11):1015–1022. doi: 10.1007/s40263-017-0477-1 Comprehensive review of lisdexamfetamine for BED, covering efficacy, safety, dosing, and clinical positioning.