What is the maximum recommended daily dose of immediate‑release dexmethylphenidate (Focalin) for the treatment of attention‑deficit/hyperactivity disorder in children, adolescents, and adults?

Maximum Dose of Immediate-Release Dexmethylphenidate (Focalin)

The maximum recommended daily dose of immediate-release dexmethylphenidate is 20 mg twice daily (40 mg total daily dose) in adults and 20 mg total daily dose in pediatric patients, as specified by FDA labeling. 1

Pediatric Dosing (Ages 6–17 Years)

• Maximum daily dose: 20 mg total (typically administered as 10 mg twice daily, given 4 hours apart). 1
• Start at 2.5 mg twice daily for patients new to methylphenidate. 1
• Titrate weekly in increments of 2.5–5 mg per dose (5–10 mg total daily increase). 1
• For patients switching from racemic methylphenidate, use half the total daily methylphenidate dose as the dexmethylphenidate dose. 1

Adult Dosing (Ages ≥18 Years)

• Maximum daily dose: 40 mg total (typically 20 mg twice daily). 1
• Start at 5 mg twice daily for patients new to methylphenidate. 1
• Titrate weekly in increments of 5–10 mg total daily dose. 1
• The 1:1 conversion applies when switching from immediate-release dexmethylphenidate to the same total daily dose. 1

Dosing Schedule and Administration

• Administer doses approximately 4 hours apart to maintain symptom coverage throughout the day. 2, 3
• The immediate-release formulation provides approximately 4 hours of therapeutic effect per dose. 4
• Give the first dose in the morning and the second dose 4 hours later; avoid late-afternoon dosing to minimize insomnia risk. 2, 5
• Doses may be taken with or without food. 1

Conversion from Other Methylphenidate Formulations

• From racemic methylphenidate: Dexmethylphenidate dose = 50% of the total daily methylphenidate dose, because dexmethylphenidate contains only the active d-enantiomer. 1, 2
• From extended-release dexmethylphenidate: Use the same total daily dose, but divide into two immediate-release doses given 4 hours apart. 1

Monitoring Requirements

• Measure blood pressure and pulse at baseline and at each dose adjustment. 6
• Track height and weight at every visit in pediatric patients, as stimulants can affect growth. 6
• Obtain weekly ADHD rating scales from parents and teachers during titration to objectively assess response. 7, 6
• Monitor for common adverse effects including decreased appetite, insomnia, headache, and abdominal pain. 2, 3, 5

Clinical Considerations

• Approximately 70–80% of patients respond to methylphenidate-class stimulants when properly titrated. 6, 8
• If adequate response is not achieved at maximum dose after 2–4 weeks, consider switching to an amphetamine-based stimulant rather than exceeding the maximum dose, as approximately 40% of patients respond preferentially to one stimulant class over the other. 6, 8
• The immediate-release formulation allows for flexible dosing adjustments and can be useful when fine-tuning individual dose timing throughout the day. 2, 5
• Doses above the FDA-recommended maximum require clear documentation that lower doses failed to control symptoms and that higher doses are not producing dose-limiting side effects. 6

Common Pitfalls to Avoid

• Do not use weight-based (mg/kg) calculations as the primary dosing strategy; systematic titration to the lowest effective dose is preferred. 6, 8
• Do not combine with monoamine oxidase inhibitors (MAOIs) or initiate within 14 days of MAOI discontinuation due to hypertensive crisis risk. 8
• Do not assume that exceeding the maximum recommended dose will provide additional benefit; if symptoms persist at maximum dose, switch medication classes or add psychosocial interventions. 6
• Do not abruptly discontinue after prolonged use at higher doses without tapering. 8