Guanfacine Extended-Release Dosing for an 8-Year-Old with ADHD
Starting Dose Recommendation
Start guanfacine extended-release at 1 mg once daily for an 8-year-old child with ADHD. 1, 2
This is the universally recommended starting dose regardless of body weight, with subsequent titration based on clinical response and tolerability. 1, 2
Titration Schedule
- Increase 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
- For most children, the maximum recommended dose is 4 mg daily, though doses up to 7 mg/day have been used in clinical contexts 2
- Weight-adjusted dosing follows a general rule of 0.1 mg/kg once daily 1, 2
Timing of Administration
Evening administration is strongly preferred to minimize daytime somnolence and fatigue, which are the most common adverse effects. 1
- Both morning and evening dosing demonstrate equivalent efficacy, but evening dosing helps prevent sedation from interfering with school performance and daily activities 1, 3
- The medication provides around-the-clock symptom control with once-daily dosing 1
Critical Timeline Expectations
Counsel families that clinical benefits typically require 2-4 weeks to observe, unlike stimulants which work immediately. 1, 4
- This delayed onset is a critical counseling point to prevent premature discontinuation 1
- Monitor ADHD symptoms systematically at each dose adjustment using parent and teacher reports 1
Monitoring Requirements
- Obtain baseline blood pressure and heart rate before initiation 1, 2
- Monitor cardiovascular parameters during dose adjustments, particularly for hypotension and bradycardia 1, 2
- Obtain personal and family cardiac history before starting 2
- Consider ECG if cardiac risk factors are present 2
Common Adverse Effects to Anticipate
- Somnolence (30-44% of patients) - usually transient and resolves over time 5, 4, 3
- Headache (20.5-26.3% of patients) 1, 4
- Fatigue (14-15.2% of patients) 1, 4
- Sedation, dry mouth, dizziness, irritability, and abdominal pain 1, 2
- Constipation (5-16% of patients, dose-dependent) 1
Critical Safety Warning
Never abruptly discontinue guanfacine - it must be tapered by 1 mg every 3-7 days to avoid rebound hypertension. 1, 2
Treatment Positioning
- Guanfacine is generally considered second-line treatment after stimulants due to smaller effect sizes (0.7 vs 1.0 for stimulants) 1, 2
- It can be used as adjunctive therapy with stimulants when stimulant monotherapy is insufficient 2
- Both guanfacine and clonidine extended-release are FDA-approved specifically for adjunctive therapy with stimulants 1