How do I convert an adult patient without cardiac disease, hypertension, or substance‑use disorder from immediate‑release Adderall to extended‑release Adderall?

Converting Immediate-Release to Extended-Release Adderall in Adults

Convert your patient's total daily dose of immediate-release Adderall directly to the same total daily dose of Adderall XR, administered once in the morning. This 1:1 conversion is straightforward because both formulations contain identical amphetamine salts in the same 3:1 dextroamphetamine-to-levoamphetamine ratio, and Adderall XR is bioequivalent to twice-daily immediate-release dosing 1, 2.

Direct Conversion Protocol

• Calculate the current total daily dose of immediate-release Adderall by summing all doses taken throughout the day 3.
• Prescribe Adderall XR at that exact total daily dose, given once each morning 3, 2.
• For example, if your patient takes immediate-release Adderall 10 mg twice daily (20 mg total), switch to Adderall XR 20 mg once daily 1, 2.
• No washout period is required—discontinue the immediate-release formulation and start Adderall XR the next morning 4.

Pharmacokinetic Rationale

• Adderall XR releases 50% of the dose immediately upon ingestion and the remaining 50% approximately 4 hours later, mimicking twice-daily immediate-release dosing 2.
• The bioavailability and pharmacokinetic profile of Adderall XR 20 mg are equivalent to immediate-release Adderall 10 mg given twice daily, 4 hours apart 1, 2.
• Adderall XR provides therapeutic coverage for approximately 12 hours with a single morning dose, eliminating the need for midday administration 2.
• Onset of action occurs within 1.5 hours, comparable to immediate-release formulations 2.

Dosing Considerations

• Typical adult therapeutic range is 10–50 mg daily, with most patients requiring 20–40 mg for optimal symptom control 3.
• If the patient's current total daily dose exceeds 50 mg, you may prescribe up to approximately 0.9 mg/kg (maximum ~65 mg) when lower doses have proven insufficient and no dose-limiting adverse effects are present 3.
• Administer in the morning (ideally before mid-morning) to minimize insomnia risk 4.
• The capsule may be swallowed whole or opened and sprinkled on applesauce if the patient cannot swallow tablets; bioavailability remains unchanged 1.

Food Effects and Administration

• Adderall XR absorption is significantly reduced by high-fat meals, resulting in markedly lower early drug exposure (first 8 hours) when taken with breakfast 5.
• To ensure consistent symptom control, instruct the patient to take Adderall XR either consistently with food or consistently on an empty stomach—not alternating between the two 5.
• If the patient eats breakfast, consider taking the medication 30–60 minutes before the meal to avoid delayed absorption 5.
• Taking the medication with meals may reduce gastrointestinal discomfort, a common adverse effect 4.

Baseline Assessment Before Conversion

• Measure blood pressure and pulse, as stimulants produce modest cardiovascular effects that may be clinically relevant in patients with preexisting conditions 3.
• Document current ADHD symptom severity using standardized rating scales to establish a baseline for comparison after conversion 3.
• Record height and weight (particularly relevant if the patient is younger, though less critical in adults) 3.
• Verify the absence of absolute contraindications: symptomatic cardiovascular disease, uncontrolled hypertension, hyperthyroidism, glaucoma, active psychosis, or concurrent MAOI use 3.

Monitoring After Conversion

• First week: Assess ADHD symptom control daily via patient report, focusing on morning, afternoon, and evening coverage 6.
• Week 2–4: Obtain weekly ADHD rating-scale scores and recheck blood pressure and pulse 3.
• Monitor for common adverse effects: decreased appetite, insomnia, headache, and irritability 6, 2.
• If insomnia develops, confirm the patient is taking the medication early in the day and not after mid-morning 4.
• Track appetite changes and consider administering the dose after breakfast if appetite suppression is problematic 4.

Titration Strategy if Needed

• If symptom control is inadequate after 1 week at the converted dose, increase by 5–10 mg weekly until symptoms are optimally controlled or adverse effects emerge 3.
• Approximately 70–80% of adults achieve good symptom control when stimulants are properly titrated 3.
• If the patient does not respond adequately to Adderall XR despite titration to 40–50 mg daily, consider switching to methylphenidate-based stimulants, as roughly 40% of patients respond preferentially to one stimulant class over the other 3.

Common Pitfalls to Avoid

• Do not reduce the total daily dose during conversion unless the patient has experienced dose-limiting adverse effects on immediate-release formulations; the extended-release formulation does not require dose reduction 1, 2.
• Do not assume the patient needs a higher dose simply because they are switching to extended-release; the 1:1 conversion is evidence-based and appropriate 1, 2.
• Do not overlook food effects—inconsistent meal timing can create day-to-day variability in symptom control with Adderall XR 5.
• Do not add a second stimulant dose in the afternoon unless the patient has completed an adequate trial (at least 2–4 weeks) of optimized Adderall XR monotherapy and still experiences late-day symptom breakthrough 3.

When to Consider Alternative Formulations

• If the patient requires fine-tuned dosing adjustments (e.g., different morning vs. afternoon doses), immediate-release formulations offer more flexibility than once-daily extended-release 4.
• If the patient experiences significant rebound effects in the late afternoon or evening despite optimal Adderall XR dosing, consider switching to lisdexamfetamine (Vyvanse), which provides 13–14 hours of coverage 4.
• If cardiovascular concerns arise (e.g., persistent blood pressure elevation), methylphenidate-based stimulants may cause less cardiovascular impact than amphetamines, though both require monitoring 7.