Guanfacine (Intuniv)
Antihypertensive (norepinephrine receptor agonist at alpha-2)
- ADHD2
- Schizophrenia negative symptoms2 and cognitive in schizotypal
- Tics1
- Neurodevelopmental disorders (self injury, aggression, cognition)
- Migraine prevention
- Less sedating than clonidine
Features
Dosing
Adults XR: Target dose is 3-4 mg qhs (some studies go up to 7 mg). Begin at 1mg qhs and raise by 1 mg/week.
Adults IR: Target dose is 1-2mg/night. Begin at 0.5mg/night and raise by 0.5-1mg/week. Benefits gradual over 2-4 weeks.
Half life 16hr (IR), 18hr (XR). Peak: 3hr (IR), 6hr (XR). Only 60% of XR is absorbed compared to IR.
INTERACTIONS: raised by depakote.
Children XR: Start 0.05–0.12 mg/kg QHS
Children IR:
Weight 27–40.5 kg (55–90 lbs): Start 0.5 mg QHS, ↑ by 0.5 mg/day at weekly intervals up to 1.5 mg/day; may ↑ to 2 mg/day after two weeks; max 2 mg/day in two to four divided doses.
Weight 40.5–45 kg (90–99 lbs): Start 0.5 mg QHS, ↑ by 0.5 mg/day at weekly intervals; max 1 mg per dose, 3 mg/day.
Weight >45 kg (>99 lbs): Start 1 mg QHS, ↑ by 1 mg/day at weekly intervals up to 3 mg/day; may ↑ to 4 mg/day after 2 weeks; max 1 mg per dose, 4 mg/day.
Management
Less sedating than clonidine, but has less evidence in psychiatric comorbidities. Can use XR or IR, but XR is FDA approved so preferred. Can augment stimulants and reduce cardiac risks and insomnia with them. Usually give at night.
TOLERABILITY: fatigue, headache, dry mouth, dizzy.
RISKS: hypotension, falls.
WITHDRAWAL: Rebound hypertension and anxiety (if they’ve been on it steadily then stop suddenly; needs to be gradually withdrawn – tapering off by 1mg every 3-7 days).
EMR Text
ADHD
Guanfacine use based on FDA approval in ADHD.
Guanfacine side effects, including hypotension, reviewed with patient.
Tics
Guanfacine use based on multiple randomized controlled trials where it reduced tics in Tourette syndrome.
Guanfacine side effects, including hypotension, reviewed with patient.
Schizophrenia and Schizotypal
Guanfacine use based on small randomized controlled trials where it improved negative symptoms in schizophrenia and cognition in schizotypal disorder.
Guanfacine side effects, including hypotension, reviewed with patient.
Neurodevelopmental disorders
Guanfacine use based on small randomized controlled trials of neurodevelopmental disorders where it improved self-injury, aggression, and cognition (Singh D et al, Am J Med Genet B Neuropsychiatr Genet, 2025; Powers JH, et al, J Child Adolesc Psychopharmacol. 2024;34(2):95-103).
Guanfacine side effects, including hypotension, reviewed with patient.