Switching from Adderall 10 mg BID to Vyvanse
Start Vyvanse at 30 mg once daily in the morning when switching from Adderall 10 mg BID (20 mg total daily dose). This represents the standard FDA-approved starting dose for adults with ADHD and provides a conservative approach that allows for upward titration based on response 1.
Rationale for 30 mg Starting Dose
- The FDA label for lisdexamfetamine specifies 30 mg once daily as the recommended starting dose in adults, regardless of prior stimulant exposure 1.
- The American College of Obstetricians and Gynecologists recommends 30 mg as the standard starting dose, though alternative approaches of 20-30 mg exist 2.
- While your patient is currently on 20 mg total daily Adderall, direct dose conversion formulas between amphetamine salts and lisdexamfetamine are not well-established in guidelines, making the standard starting dose the safest approach 3, 4.
Titration Protocol After Initiation
- Increase by 10 mg or 20 mg increments at approximately weekly intervals based on symptom control and tolerability, up to a maximum of 70 mg once daily 1.
- The American Academy of Pediatrics recommends obtaining standardized ADHD rating scales before each dose increase to objectively assess response 2.
- Most patients require titration beyond 30 mg to achieve optimal symptom control, with target doses typically ranging from 50-70 mg daily 3, 1.
Critical Monitoring Parameters
- Assess blood pressure and pulse at baseline and with each dose increase, as cardiovascular monitoring is essential during stimulant therapy 4, 2.
- Evaluate both therapeutic effects (attention, focus, task completion) and side effects (appetite, sleep, mood) before each dose adjustment 4.
- Monitor for decreased appetite, insomnia, upper abdominal pain, headache, and weight changes, which are the most common adverse events with lisdexamfetamine 5.
Administration Considerations
- Administer in the early morning (with or without food) to provide all-day coverage and minimize insomnia risk 2, 1.
- Lisdexamfetamine provides 12-14 hours of symptom control from a single morning dose, eliminating the need for afternoon dosing required with immediate-release Adderall 3, 6.
- The prodrug formulation requires enzymatic conversion to active d-amphetamine in the blood, resulting in lower abuse potential and more consistent pharmacokinetics compared to immediate-release formulations 7, 6.
Why Not Start Higher Than 30 mg
- Starting at too high a dose increases the risk of unnecessary side effects and decreased medication adherence 4.
- The prodrug mechanism of lisdexamfetamine produces different pharmacokinetics than immediate-release Adderall, with lower peak plasma concentrations and more gradual onset, making direct dose equivalency unreliable 6, 5.
- Systematic titration from 30 mg allows you to identify the optimal dose for this individual patient, as approximately 70% of patients respond when proper titration protocols are followed 3, 4.
Common Pitfalls to Avoid
- Do not assume the patient needs 40-50 mg simply because they were on 20 mg total daily Adderall - the prodrug formulation and extended duration of action make direct conversion inappropriate 6.
- Do not skip the 30 mg starting dose and begin at higher doses, as this contradicts FDA labeling and increases adverse event risk 1.
- Do not increase doses more frequently than weekly intervals, as insufficient time between adjustments prevents proper assessment of therapeutic response 4, 2.
- Avoid afternoon or evening dosing, which can cause significant insomnia due to the 12-14 hour duration of action 2, 1.