What is the recommended dosing schedule for lisdexamfetamine (Vyvanse) in adults and pediatric patients, and how should the dose be adjusted for hepatic impairment?

Vyvanse (Lisdexamfetamine) Dosing

Start lisdexamfetamine at 30 mg once daily in the morning for both adults and pediatric patients 6 years and older with ADHD, then titrate in 10-20 mg increments weekly to a target of 30-70 mg daily, with a maximum of 70 mg/day. 1

Standard Dosing Regimen

ADHD Treatment

• Starting dose: 30 mg once daily in the morning 1
• Titration: Increase by 10-20 mg increments at approximately weekly intervals 1
• Target range: 30-70 mg daily 1
• Maximum dose: 70 mg/day 1
• Administration: Take in the morning with or without food; avoid afternoon doses due to insomnia risk 1

Binge Eating Disorder (Adults Only)

• Starting dose: 30 mg once daily 1
• Titration: Increase by 20 mg increments weekly 1
• Target range: 50-70 mg daily 1
• Maximum dose: 70 mg/day 1

Administration Options

Lisdexamfetamine offers flexible administration methods 1:

• Swallow capsules whole, OR
• Open capsules and mix entire contents with yogurt, water, or orange juice (consume immediately; do not store)
• Chewable tablets must be chewed thoroughly before swallowing
• Never divide a single dose - take at least one full capsule or tablet per day 1

Dose Adjustments for Renal Impairment

Reduce maximum doses in renal dysfunction 1:

• Severe renal impairment (GFR 15 to <30 mL/min/1.73 m²): Maximum 50 mg/day
• End-stage renal disease (GFR <15 mL/min/1.73 m²): Maximum 30 mg/day

Hepatic Impairment

The FDA label does not specify dose adjustments for hepatic impairment 1. Since lisdexamfetamine is a prodrug converted by red blood cell enzymatic hydrolysis (not hepatic metabolism), standard dosing can be used in hepatic dysfunction.

Drug Interaction Considerations

Adjust doses when urinary pH is altered 1:

• Acidifying agents (e.g., ascorbic acid): Decrease amphetamine blood levels - may need higher lisdexamfetamine doses
• Alkalinizing agents (e.g., sodium bicarbonate): Increase amphetamine blood levels - may need lower lisdexamfetamine doses

Clinical Context and Positioning

Lisdexamfetamine is recommended as first-line therapy in the United States but second-line in many European countries 2. The 2011 AAP guidelines note that while lisdexamfetamine has lower abuse potential due to its prodrug design, it should be considered particularly in adolescents at risk for diversion 3. The prodrug formulation requires enzymatic hydrolysis by red blood cells, making it only active after ingestion and providing approximately 12-14 hours of symptom control 4, 5.

Pretreatment Requirements

Before initiating lisdexamfetamine, assess 1:

• Cardiac disease: Obtain careful history, family history of sudden death or ventricular arrhythmia, and perform physical exam
• Tics/Tourette's: Evaluate family history and clinically assess for motor or verbal tics

Common Pitfalls

• Avoid afternoon dosing - insomnia is a common adverse effect 1
• Do not use in children <6 years - younger pediatric patients experience more long-term weight loss 1
• Monitor for diversion in adolescents - though abuse potential is lower than immediate-release amphetamines, monitoring remains important 3
• Not indicated for weight loss - despite appetite suppression effects, lisdexamfetamine is not approved for obesity treatment 1