Intuniv

Forms/Strengths

Age: ≥ 6 y/o
Duration: ~ 24 hours
Considerations: Avoid high-fat meals; do not crush, chew, or break tablets
Initial Dose: 1 mg daily
Titration: 1 mg/week
Max Dose:
- 25 - 33.9 kg: 2 - 3 mg/day
- 34 - 41.4 kg: 2 - 4 mg/day
- 41.5 - 49.4 kg: 3 - 5 mg/day
- 49.5 - 58.4 kg: 3 - 6 mg/day
- 58.5 - 91 kg: 4 - 7 mg/day
- 91+ kg: 5 - 7 mg/day

Guanfacine (Intuniv) is a selective alpha-2A adrenergic receptor agonist; enhances prefrontal cortex regulation
Reduces impulsivity and hyperactivity; may be less effective for inattention
Non-stimulant option for ADHD; useful as adjunct therapy with stimulants
Primarily metabolized by CYP3A4; dose adjustments may be necessary with CYP3A4 inhibitors or inducers
Common side effects: drowsiness, fatigue, hypotension, dry mouth

Oppositional Defiant Disorder (F91.3): May help manage irritability, anger outbursts, and impulsive aggression.
Anxiety Disorders (F41.9): Sometimes used to reduce symptoms of anxiety and related somatic complaints.
Tic Disorders/Tourette’s Syndrome (F95.2): Occasionally employed off-label to help reduce tics.
Autism Spectrum Disorder-Associated Irritability (F84.0): May help in managing irritability and aggression in some cases.

Take once daily, preferably at the same time each day.
Swallow the tablet whole; do not crush, chew, or split.
Take with or without food, but be consistent with food intake to maintain stable absorption.
If a dose is missed, take it as soon as possible unless it is close to the next dose—do not double up.
Do not abruptly stop taking; tapering may be required to prevent rebound hypertension.

Common: Sedation, somnolence, headache, abdominal pain, hypotension, bradycardia.

Serious: Syncope, rebound hypertension, cardiac conduction abnormalitie

Cardiovascular: Baseline and routine monitoring of heart rate and blood pressure.
Psychiatric Symptoms: Observe for mood changes, anxiety, or psychosis.

When to Call the Doctor:
- Severe dizziness, fainting, or low blood pressure.
- Slow or irregular heart rate.
- Excessive drowsiness or difficulty waking.
- Mood changes, depression, or unusual behavior.
- Severe headache, blurred vision, or confusion (possible hypertensive rebound if stopped abruptly).
Safety Tips:
- Monitor blood pressure and heart rate regularly.
- Avoid alcohol and sedatives, which may enhance drowsiness.
- Rise slowly from sitting or lying positions to prevent dizziness.
- Use caution when driving or operating heavy machinery due to possible sedation.
- Taper gradually when discontinuing to avoid withdrawal symptoms.
Parent Tips for Pediatric Patients:
- May cause daytime drowsiness; consider giving the dose at bedtime if drowsiness is problematic.
- Monitor for irritability, mood swings, or behavioral changes.
- Encourage hydration and balanced nutrition to minimize side effects.
- Ensure children do not engage in high-risk activities (e.g., swimming, biking) if excessively drowsy.

Contraindications:
- Hypersensitivity to guanfacine or formulation components.
- Use with caution in patients with severe heart disease, bradycardia, or hypotension.
Pregnancy:
- Category B; no well-controlled studies in pregnant women, but animal studies suggest minimal risk.
Lactation:
- Excreted in breast milk; use with caution due to potential effects on infant blood pressure.
Drug Interactions:
- CNS depressants (e.g., alcohol, benzodiazepines) may increase sedation.
- Beta-blockers may enhance bradycardia; caution when using together.
- Stimulants (e.g., amphetamines) may counteract guanfacine’s effects.
- Antihypertensive medications may lead to excessive blood pressure lowering.