Maximum Dose of Intuniv (Guanfacine) for ADHD
The maximum daily dose of Intuniv (guanfacine extended-release) is 7 mg per day, or 0.12 mg/kg/day, whichever is lower. 1
Dosing Algorithm
Starting Dose
- Begin with 1 mg once daily in the morning 1
Titration Schedule
- Increase by 1 mg per week based on clinical response and tolerability 1
- Continue weekly increases until reaching the target dose range or maximum dose 1
Target Dose Range
- Recommended target range: 1-7 mg/day 1
- Weight-based dosing: 0.05 to 0.12 mg/kg/day 1
- Most clinical trials used optimized doses of 1-4 mg/day 2, 3
Maximum Dose Limits
- Absolute maximum: 7 mg per day 1
- Weight-based maximum: 0.12 mg/kg/day 1
- Use whichever limit is lower for the individual patient 1
Important Clinical Considerations
Monitoring During Titration
- The most common side effects are somnolence (38-51%), headache (20-22%), sedation (13%), and fatigue (11-15%) 2, 3, 4
- Sedation-related events are most common during dose titration but typically resolve over time, with 63.5% resolving before the taper period 3
- Monitor blood pressure and heart rate, as modest reductions are common but usually not clinically significant 5, 2, 3
Common Pitfall to Avoid
- Do not exceed 7 mg/day or 0.12 mg/kg/day, as this exceeds the approved maximum dose and increases risk of adverse effects without additional benefit 1
- Titrating too quickly (faster than 1 mg per week) increases the risk of sedation and other side effects 1
Evidence Quality Note
- Guanfacine has limited efficacy data in adults compared to children and adolescents aged 6-17 years 1
- The medication is approved in Canada only for children and adolescents aged 6-17 years 1
- Recent meta-analysis confirms guanfacine is safe and effective for ADHD treatment, with stronger evidence in children than adults 4