What is the recommended dosing of Zenzedi (extended‑release methylphenidate) for children (6–12 years), adolescents (≥13 years), and adults?

Zenzedi Dosing for ADHD

Zenzedi (dextroamphetamine) should be initiated at 2.5 mg once or twice daily in the morning and around noon, with weekly titration by 2.5–5 mg increments until optimal symptom control is achieved, up to a maximum of 40 mg daily in children/adolescents and 10–50 mg daily in adults. 1

Starting Doses by Age Group

Children (6–12 years):

• Start with 2.5 mg once daily in the morning after breakfast 1
• May add a second dose around noon after lunch if needed 1
• Children weighing less than 25 kg generally should not receive single doses greater than 10 mg 1

Adolescents (≥13 years):

• Start with 2.5 mg once or twice daily (morning and noon) 1
• Maximum single dose typically 10 mg for those under 25 kg 1

Adults:

• Start with 2.5 mg once or twice daily 1
• Typical therapeutic range is 10–50 mg total daily dose 2
• Maximum recommended dose is 40 mg daily per PDR, though consensus from practice suggests doses may occasionally go higher with clear documentation 1

Titration Schedule

• Increase dose weekly by 2.5–5 mg per dose based on symptom response and tolerability 1
• Use 2 or 3 times daily dosing due to the short duration of action (approximately 4 hours per dose) 1
• Maximum total daily dose is calculated by adding all doses taken during the day 1

Critical Monitoring Requirements

Baseline assessment:

• Blood pressure, pulse, height, and weight in the context of a physical examination 1
• Detailed cardiac history and family history of cardiovascular disease 3

During titration:

• Weekly contact by telephone or in-person 1
• Assess target ADHD symptoms using parent and teacher rating scales 1
• Monitor for side effects: insomnia, anorexia, headaches, social withdrawal, tics, weight loss 1

Maintenance phase:

• Adults: blood pressure and pulse checked quarterly 1
• Children/adolescents: vital signs checked annually during routine physical examination 1
• Weight at each visit to objectively measure appetite effects 1
• Monthly follow-up appointments until symptoms stabilized 1

Important Clinical Considerations

Dosing principles:

• Minimum effective doses should be used to initiate therapy 1
• If the top recommended dose does not help, more is not necessarily better—consider changing drugs or adding environmental/psychosocial interventions 1
• Systematic titration to optimal effect is more important than strict mg/kg calculations 2

Common pitfalls to avoid:

• Do not assume low doses (e.g., 5 mg daily) are adequate without proper titration 2
• Dextroamphetamine has greater effects on appetite and sleep compared to methylphenidate due to its longer excretion half-life 1
• Avoid use with MAO inhibitors (14-day washout required) 2, 3

Contraindications:

• Symptomatic cardiovascular disease or uncontrolled hypertension 3
• Active psychosis or mania 3
• Concurrent MAO inhibitor use 3
• Glaucoma, hyperthyroidism, or prior hypersensitivity to amphetamines 3

Special Populations

Substance use history:

• Exercise caution and consider long-acting formulations with lower abuse potential 2, 3
• Implement weekly monitoring during titration and monthly follow-up during maintenance 2

Comorbid conditions:

• Depression/anxiety: Dextroamphetamine can be safely combined with SSRIs (no pharmacokinetic interactions) 3
• Bipolar disorder: Stabilize mood with mood stabilizers before initiating stimulants 2