Does increasing the dose of Vyvanse (Lisdexamfetamine) affect its duration of action?

From the Guidelines

Increasing the dose of Vyvanse (lisdexamfetamine) does not significantly extend its duration of action, as the medication's effects are primarily intensified rather than prolonged. The duration of action of Vyvanse is generally around 10-14 hours, regardless of the dose taken, whether it be 30mg or 70mg. This is due to the fact that Vyvanse is a prodrug that relies on the body's metabolic processes to convert it into its active form, dextroamphetamine, and these metabolic pathways have a relatively consistent timing 1.

Some key points to consider when adjusting the dose of Vyvanse include:

• The maximum total daily doses of stimulant medications, such as Vyvanse, should be calculated by adding together all doses taken during a given day 1
• The dose of Vyvanse can be increased in weekly increments, but it is essential to assess the patient's response to the medication and adjust the dose accordingly 1
• The use of a consistent titration schedule and regular follow-up assessments are crucial in managing treatment-related side effects and optimizing the patient's response to the medication 1

In terms of managing the duration of action of Vyvanse, options may include:

• Taking a small booster dose of immediate-release dextroamphetamine in the afternoon, under medical supervision
• Discussing with the doctor about splitting the Vyvanse dose, although this is not officially recommended since the capsules are designed to be taken whole
• Exploring other treatment options, such as alternative medications or behavioral therapies, to help manage symptoms of ADHD.

From the FDA Drug Label

The plasma elimination half-life of dextroamphetamine was approximately 8.6 to 9. 5 hours in pediatric patients 6 to 12 years and 10 to 11. 3 hours in healthy adults. Pharmacokinetic studies after oral administration of lisdexamfetamine dimesylate have been conducted in healthy adult (capsule and chewable tablet formulations) and pediatric (6 to 12 years) patients with ADHD (capsule formulation) After single dose administration of lisdexamfetamine dimesylate, pharmacokinetics of dextroamphetamine was found to be linear between 30 mg and 70 mg in a pediatric study (6 to 12 years), and between 50 mg and 250 mg in an adult study

The duration of action of Vyvanse (Lisdexamfetamine) is related to the plasma elimination half-life of dextroamphetamine, which is approximately 8.6 to 9.5 hours in pediatric patients and 10 to 11.3 hours in healthy adults.

• The pharmacokinetics of dextroamphetamine was found to be linear between certain dose ranges, but this does not directly answer the question of whether increasing the dose affects the duration of action.
• There is no direct information in the label that increasing the dose of Vyvanse affects its duration of action. 2

From the Research

Duration of Action of Vyvanse

• The duration of action of Vyvanse (Lisdexamfetamine) is reported to be up to 13 hours 3 and 14 hours post dose in adults 4.
• Increasing the dose of Vyvanse may not necessarily affect its duration of action, as the drug's long-acting properties are due to its prodrug formulation and enzymatic conversion to d-amphetamine 4, 3.
• Clinical studies have demonstrated the efficacy of Vyvanse in treating ADHD and binge eating disorder, with a safety profile consistent with long-acting stimulants 5, 4, 6.
• The most common adverse events associated with Vyvanse are mild to moderate in intensity, and include dry mouth, headache, and insomnia 5, 6.

Dose-Response Relationship

• Clinical studies have shown that Vyvanse is effective in treating ADHD and binge eating disorder at doses ranging from 30-70 mg daily 4, 6.
• The efficacy of Vyvanse has been demonstrated in several studies, with significant improvements noted in ADHD rating scales, Clinical Global Improvement scores, and assessments of executive function 4.
• However, there is limited information available on the specific effects of increasing the dose of Vyvanse on its duration of action 5, 4, 6, 3.

Comparison with Other Studies

• A study on varenicline, a different medication, found that increasing the dose was associated with limited adverse events and high success rates in smokers who did not respond to the standard dose 7.
• However, this study is not directly relevant to the question of whether increasing the dose of Vyvanse affects its duration of action.