Conversion from Adderall XR 20mg to Concerta
When converting from Adderall XR 20mg to Concerta, start with Concerta 54mg once daily in the morning, based on FDA-approved conversion guidance for equivalent methylphenidate dosing.
Conversion Rationale
The FDA label for Concerta provides specific conversion guidance for patients switching from other methylphenidate formulations 1. While this doesn't directly address amphetamine-to-methylphenidate conversion, the established clinical approach uses approximate equipotency ratios:
- Amphetamine to methylphenidate ratio: Approximately 1:2 (meaning amphetamines are roughly twice as potent as methylphenidate on a mg-per-mg basis)
- Adderall XR 20mg contains: 12.5mg amphetamine base equivalence 2
- Approximate methylphenidate equivalent: 25-30mg total daily dose of immediate-release methylphenidate
According to the Concerta conversion table, patients taking 15mg methylphenidate twice or three times daily (30-45mg total daily) should start with Concerta 54mg 1. Patients on 10mg methylphenidate twice or three times daily (20-30mg total) convert to Concerta 36mg 1.
Recommended Starting Approach
Start with Concerta 54mg once daily, as this represents the middle-ground conversion for a patient on Adderall XR 20mg:
- Administer once daily in the morning with or without food 1
- Must be swallowed whole—cannot be chewed, divided, or crushed 1
- Monitor response over 1 week before adjusting
Titration Strategy
If the initial 54mg dose is insufficient or produces side effects:
- Increase by 18mg increments at weekly intervals if symptom control is inadequate 1
- Decrease to 36mg if side effects are problematic
- Maximum dose is 72mg daily in adolescents and adults 1
- Clinical judgment should guide final dosing based on symptom control and tolerability 1
Important Clinical Considerations
Key differences between medications:
- Concerta provides consistent methylphenidate exposure regardless of food intake, unlike Adderall XR where high-fat meals significantly reduce early drug exposure 3
- Methylphenidate (Concerta) and amphetamines (Adderall XR) have different mechanisms: methylphenidate primarily blocks dopamine/norepinephrine reuptake, while amphetamines also increase monoamine release and have additional mechanisms 4
- Approximately 70% respond to either medication alone, but nearly 90% respond if both are tried 5
Monitoring requirements:
- Assess blood pressure and pulse at each visit 4
- Monitor weight and appetite 5, 4
- Evaluate ADHD symptom control using rating scales from multiple sources 5
- Weekly contact during titration phase, then monthly once stabilized 5
Common pitfalls to avoid:
- Don't assume 1:1 dose equivalence—amphetamines are more potent per mg
- Don't crush or open Concerta tablets (unlike Adderall XR capsules which can be opened) 1
- Don't underdose—flexible titration to higher doses improves both efficacy and acceptability 6
If the patient fails to achieve adequate response after appropriate titration over one month, consider switching back to an amphetamine formulation or trying alternative ADHD medications 1.