What is the recommended dosing of Intuniv (guanfacine) for children and adolescents?

Intuniv (Guanfacine Extended-Release) Dosing for Children and Adolescents

Start with 1 mg once daily and titrate by 1 mg per week based on response and tolerability, targeting a dose range of 0.05 to 0.12 mg/kg/day or 1 to 7 mg/day. 1, 2

Starting Dose

• Begin at 1 mg once daily for all children and adolescents aged 6-17 years 1, 2
• Administer in the evening to minimize daytime somnolence and fatigue, which are the most common adverse effects 2

Titration Schedule

• Increase by 1 mg increments weekly based on clinical response and tolerability 1, 2
• Continue weekly titration until reaching the optimal therapeutic dose or maximum tolerated dose 2
• Allow 2-4 weeks at the optimized dose before assessing full therapeutic response, as guanfacine has delayed onset of action unlike stimulants 2

Target Dose Range

• Weight-based dosing: 0.05 to 0.12 mg/kg/day 1, 2
• Absolute dose range: 1 to 7 mg/day 1, 2
• For children aged 6-12 years: typical optimal doses are 1-4 mg/day 1, 3
• For adolescents aged 13-17 years: typical optimal doses are 1-7 mg/day, with many requiring doses above 4 mg 1, 4

Practical Dosing Considerations

Dose Distribution in Clinical Trials

• In adolescent studies, the majority received optimal doses of 3-6 mg daily, with 46.5% requiring doses above the 4 mg limit initially approved for younger children 4
• Most common optimal doses across age groups: 3 mg (22.9%), 4 mg (19.8%), 5 mg (20.6%), and 6 mg (18.3%) 4

Monitoring During Titration

• Obtain baseline blood pressure and heart rate before initiating therapy 2
• Monitor cardiovascular parameters at each dose adjustment, particularly for hypotension and bradycardia 2
• Systematically assess ADHD symptoms using parent and teacher reports at each dose change 2
• Watch for sedation-related adverse events, which are most common during dose titration but typically resolve (63.5% resolved before taper period in trials) 5

Critical Safety Warnings

Discontinuation Protocol

• Never abruptly discontinue guanfacine—this can cause rebound hypertension 2
• Taper by 1 mg every 3-7 days when discontinuing treatment 2
• If multiple doses are accidentally missed, contact healthcare provider before restarting—do not resume at full dose without medical guidance 2

Common Adverse Effects (Dose-Related)

• Somnolence (50.7%), sedation (13.2%), and fatigue (11.0%) are most frequent 5
• Headache (22.1%), upper abdominal pain (11.8%), and constipation (5-16%) also occur commonly 5, 2
• Sedation-related events occurred in 62.5% of subjects but were mostly mild-to-moderate and transient 5
• 70.1% of adverse events were mild-to-moderate in severity 3

Cardiovascular Effects

• Expect modest decreases in blood pressure and heart rate, typically not clinically significant 2, 3
• Monitor for bradycardia and hypotension, particularly during dose adjustments 2
• Patients with cardiac history (Wolf-Parkinson-White syndrome, unexplained syncope, family history of sudden cardiac death) require special consideration 2

Special Populations

Pregnancy and Breastfeeding

• Use with caution in pregnancy—limited safety data available 1, 2
• One small study in preeclampsia showed no congenital malformations but 20% of infants had low birth weight 1, 2
• No published studies exist for guanfacine use while breastfeeding 1
• Alternative agents are generally preferred in these populations 1

Renal Impairment

• Dose adjustments may be necessary based on creatinine clearance, though specific pediatric guidelines are limited 6

Clinical Efficacy Expectations

• Effect size versus placebo: 0.52-0.92 for ADHD symptom reduction 5, 3, 4
• Significant improvements in oppositional symptoms (effect size 0.59) when these co-occur with ADHD 5
• Improvements in functional impairment, particularly in learning/school and family domains 3
• Sustained benefits over 24 months in open-label extension trials 2
• Once-daily dosing provides "around-the-clock" symptom control 2

Position in Treatment Algorithm

• Generally recommended as second-line treatment after stimulants due to smaller effect sizes compared to stimulants 2
• Can be used as adjunctive therapy with stimulants—FDA-approved for this indication 2
• Particularly appropriate when ADHD co-occurs with oppositional symptoms or disruptive behavior 2, 5
• Consider as first-line in patients with substance use disorders (non-controlled medication) or when stimulants are contraindicated 2