What is Vyvanse (lisdexamfetamine dimesylate) used for, how is it dosed, and what are its contraindications and common adverse effects?

Vyvanse (Lisdexamfetamine Dimesylate): Clinical Overview

Vyvanse is a long-acting prodrug stimulant FDA-approved for ADHD in patients aged 6 years and older, and for moderate-to-severe binge eating disorder (BED) in adults. 1

Indications

ADHD Treatment

• First-line therapy for ADHD in children (≥6 years), adolescents, and adults 2
• In Europe, lisdexamfetamine is approved as second-line therapy after methylphenidate failure, while in the United States it holds first-line status 2
• Preferred next option when methylphenidate provides inadequate benefit 2

Binge Eating Disorder

• FDA-approved for moderate-to-severe BED in adults 3
• Reduces binge-eating days by approximately 1.29 days per week compared to placebo 3

Special Populations

• Adolescents with substance abuse concerns: Lisdexamfetamine has lower abuse potential than immediate-release stimulants because it requires enzymatic conversion in red blood cells to become active, making extraction and alternative routes of administration (snorting, injection) ineffective 4
• Patients requiring extended symptom control: Provides 13-hour duration in children and 14-hour duration in adults, beneficial for homework completion and evening driving in adolescents 4, 5

Dosing

ADHD

• Starting dose: 30 mg once daily in the morning 1
• Titration: Increase by 10-20 mg weekly intervals
• Therapeutic range: 30-70 mg daily
• Maximum dose: 70 mg daily
• Administration: Once-daily dosing; can be taken as capsule or opened and mixed with water 1

Binge Eating Disorder

• Similar dosing strategy: 30-70 mg daily 3

Key advantage: Once-daily dosing improves medication adherence compared to multiple-daily-dosing regimens 2

Mechanism of Action

Lisdexamfetamine is a therapeutically inactive prodrug that requires enzymatic hydrolysis primarily in red blood cells to convert to active d-amphetamine 2, 5. This conversion is:

• Unaffected by gastrointestinal pH
• Independent of gastrointestinal transit time
• Rate-limited, providing consistent plasma concentrations throughout the day 5

The active d-amphetamine enhances dopamine and norepinephrine activity in the prefrontal cortex, optimizing executive function and attention 2

Contraindications (Absolute)

Do not prescribe Vyvanse in patients with: 1

1. Known hypersensitivity to amphetamine products (anaphylaxis, Stevens-Johnson Syndrome, angioedema, urticaria reported)
2. Current MAOI use or within 14 days of MAOI discontinuation (risk of hypertensive crisis)
3. Structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmias, or coronary artery disease (sudden death reported in patients with serious cardiac disease) 1

Common Adverse Effects

Most Frequent (>10% incidence) 1, 6

• Decreased appetite (most common)
• Insomnia
• Headache
• Weight loss
• Dry mouth
• Irritability
• Upper abdominal pain
• Nausea

Cardiovascular Effects 1

• Mean blood pressure increase: 2-4 mmHg
• Mean heart rate increase: 3-6 bpm
• Monitor all patients for tachycardia and hypertension

Serious Adverse Effects (Rare but Important) 1

Psychiatric reactions:

• New-onset psychotic or manic symptoms (0.1% in pooled studies)
• Exacerbation of pre-existing psychosis
• Induction of manic episodes in bipolar disorder

Peripheral vasculopathy including Raynaud's phenomenon (observe for digital changes)

Serotonin syndrome when combined with:

• MAOIs (contraindicated)
• SSRIs, SNRIs, triptans, tricyclic antidepressants
• Tramadol, fentanyl, lithium, St. John's Wort
• CYP2D6 inhibitors 1

Motor and verbal tics: May precipitate or worsen tics and Tourette's syndrome 1

Growth suppression: Monitor height and weight in pediatric patients during long-term treatment 1

Discontinuation Rates

• Pediatric patients (6-12 years): 8% discontinued due to adverse effects vs. 0% placebo 1
• Adolescents (13-17 years): 3% discontinued vs. 1% placebo 1
• Adults: 6% discontinued vs. 2% placebo 1

Most adverse effects are mild to moderate and transient 5, 7

Clinical Pearls

Advantages Over Other Stimulants

• Lower diversion risk: Prodrug design makes abuse via non-oral routes ineffective 4
• Consistent duration: Reliable 13-14 hour coverage without need for afternoon dosing 5
• Once-daily dosing: Improves adherence, eliminates school-based medication administration 2

Monitoring Requirements

• Baseline: Screen for cardiac disease, psychiatric history (psychosis, bipolar disorder, tics), family history of sudden cardiac death
• Ongoing: Blood pressure, heart rate, weight, height (pediatrics), signs of abuse/diversion, psychiatric symptoms, peripheral vasculopathy 1

Common Pitfalls to Avoid

• Do not prescribe without cardiac screening in patients with cardiac symptoms or family history of sudden cardiac death
• Screen for bipolar disorder before initiating—stimulants can precipitate manic episodes 1
• Assess substance abuse risk in adolescents and monitor for diversion 4
• Avoid evening dosing—long duration may worsen insomnia
• Do not combine with MAOIs or within 14 days of MAOI discontinuation 1

When to Choose Lisdexamfetamine

• Methylphenidate failure or inadequate response 2
• Concerns about medication diversion in adolescents 4
• Need for extended symptom control into evening hours 4
• Comorbid binge eating disorder in adults 3
• Preference for once-daily dosing to improve adherence 2