Guanfacine (Intuniv) Dosing for Teenagers with ADHD
The recommended dosing for Intuniv (guanfacine extended release) in teenagers with ADHD is 0.1 mg/kg once daily (as a rule of thumb), with available doses of 1,2,3, and 4 mg tablets, and should not exceed 4 mg daily. 1
Initial Dosing and Titration
- Starting dose: Begin with 1 mg once daily
- Administration timing: Preferably in the evening due to potential somnolence/fatigue side effects
- Titration schedule:
- Adjust dose after 3-4 weeks if needed
- Increase by 1 mg increments
- Target dose: 0.1 mg/kg once daily
- Maximum dose: 4 mg daily
Pharmacological Considerations
- Guanfacine is an alpha-2A adrenoceptor agonist approved for ADHD treatment in children and adolescents aged 6-17 years 2
- Extended-release formulation (Intuniv) is specifically designed for once-daily dosing
- Important: Extended-release guanfacine is NOT substitutable on a mg-for-mg basis with immediate-release guanfacine due to different pharmacokinetics 2
- Treatment effects typically begin to appear after 2-4 weeks of therapy 1
Monitoring and Side Effects
- Common side effects: Somnolence (50.7%), fatigue (11%), sedation (13.2%), headache (22.1%) 3
- Cardiovascular effects: Monitor for hypotension/bradycardia
- Modest reductions in blood pressure and heart rate are common but rarely clinically significant 2
- Regular vital sign monitoring is essential
- Other potential adverse effects: Irritability, insomnia, nightmares 1
Clinical Efficacy
- Guanfacine has demonstrated efficacy for ADHD with an effect size of approximately 0.7 (medium range) 1
- Effect sizes are generally smaller than stimulants but still clinically meaningful 1
- Guanfacine has shown improvements in both functional impairment and quality of life 1
- Long-term maintenance of treatment effects has been documented 1
Treatment Considerations
- Guanfacine is generally considered a second-line treatment after stimulants 1
- May be particularly beneficial when:
Important Precautions
- Contraindicated in patients with significant cardiovascular history 2
- Avoid abrupt discontinuation; taper gradually to prevent rebound effects
- When discontinuing, blood pressure typically returns to pretreatment levels within 2-4 days 4
Adjunctive Therapy
- Can be used as adjunctive therapy with stimulants in patients with suboptimal response to stimulant monotherapy 5
- When used as adjunctive therapy, lower doses may be appropriate
Guanfacine extended release provides an effective non-stimulant option for ADHD treatment in teenagers, with particular benefits for those needing 24-hour symptom control or those with concurrent oppositional symptoms.