What is the recommended starting dose of guanfacine (Intuniv) for Attention Deficit Hyperactivity Disorder (ADHD) treatment?

Guanfacine Starting Dose for ADHD

Start guanfacine extended-release at 1 mg once daily, administered in the evening, and titrate by 1 mg per week based on clinical response and tolerability. 1, 2

Initial Dosing Strategy

• The recommended starting dose is 1 mg once daily for all patients, regardless of age or weight 1, 2
• Evening administration is strongly preferred over morning dosing to minimize daytime somnolence and sedation, which are the most common adverse effects 1, 2
• The medication provides 24-hour symptom control with once-daily dosing 1

Titration Protocol

• Increase the dose by 1 mg per week based on clinical response and tolerability 1, 2
• The target dose range is 0.05 to 0.12 mg/kg/day or 1 to 7 mg/day 1, 2
• A practical rule of thumb is to aim for approximately 0.1 mg/kg once daily 1, 2
• The maximum recommended dose is typically 4 mg daily in most clinical contexts, though doses up to 7 mg daily have been used 2
• Available tablet strengths are 1,2,3, and 4 mg 2

Critical Timing Expectations

• Counsel families that therapeutic effects require 2-4 weeks to manifest, unlike stimulants which work immediately 1, 2
• This delayed onset is a critical counseling point to prevent premature discontinuation due to unrealistic expectations 1
• Monitor ADHD symptoms systematically at each dose adjustment using parent and teacher reports 1

Pre-Treatment Requirements

• Obtain baseline blood pressure and heart rate before initiating therapy 1, 2
• Obtain personal and family cardiac history, particularly for Wolf-Parkinson-White syndrome, unexplained fainting, or family history of sudden cardiac death 1, 2
• Consider ECG if cardiac risk factors are present 2

Common Pitfalls to Avoid

• Never abruptly discontinue guanfacine—it must be tapered by 1 mg every 3-7 days to avoid rebound hypertension 1, 2
• Do not restart at full dose if multiple doses are accidentally missed; contact the healthcare provider for guidance 1
• Do not substitute immediate-release guanfacine for extended-release on a milligram-for-milligram basis, as the pharmacokinetics differ 3

Monitoring During Treatment

• Monitor blood pressure and heart rate at each dose adjustment, as modest decreases are common though typically not clinically significant 1, 2
• Most common adverse effects include somnolence (38.6-50.7%), headache (20.5-22.1%), and fatigue (15.2%) 1, 4, 5, 6
• These sedation-related effects typically emerge within the first 2 weeks and generally resolve with continued treatment 1, 5

Treatment Positioning

• Guanfacine is generally recommended as second-line treatment after stimulants due to smaller effect sizes (0.7 for guanfacine versus 1.0 for stimulants) 1, 2
• It is FDA-approved for both monotherapy and adjunctive therapy with stimulants when stimulant therapy alone is insufficient 1, 2
• Guanfacine is approved for children and adolescents aged 6-17 years; it is not recommended for preschool-aged children (4-5 years) due to insufficient study data 2