Guanfacine ER
Generic: guanfacine hydrochloride extended-release · Brand: Intuniv® · Class: Non-Stimulant — Alpha-2A Agonist
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How It Works
Guanfacine extended-release is a non-stimulant alpha-2A adrenergic receptor agonist. Rather than increasing dopamine or norepinephrine levels, it selectively activates alpha-2A receptors in the prefrontal cortex — the area of the brain responsible for impulse control, working memory, and attention. This improves the signal-to-noise ratio in prefrontal circuits without the stimulating effects of amphetamines. It is particularly effective for hyperactivity, impulsivity, aggression, and emotional dysregulation — and does not worsen anxiety or tics. It can be used alone or added to a stimulant for enhanced effect.
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What It Treats
ADHD in Children 6–17FDA-approved as monotherapy or adjunct to stimulants
Hyperactivity and ImpulsivityParticularly effective for the hyperactive-impulsive presentation
ADHD with TicsDoes not worsen tics — often helps reduce them
ADHD with AggressionEffective for emotional dysregulation and aggressive behaviors
Stimulant AugmentationCommonly added to stimulants when hyperactivity or sleep remain problematic
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Dosing Overview
| Population | Start | Typical Range | Max |
|---|---|---|---|
| Children 6–17 ADHD monotherapy | 1 mg once daily | 1–4 mg/day | 4 mg/day |
| Children 6–17 Adjunct to stimulant | 1 mg once daily | 1–4 mg/day | 4 mg/day |
| Adults Off-label ADHD | 1 mg at bedtime | 1–4 mg/day | 4 mg/day |
Taken once daily — can be taken morning or evening depending on sedation. Do not take with high-fat meals (increases absorption significantly). Do not crush or chew. Taper slowly when stopping — do not stop abruptly.
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Side Effects
Common
- Sedation or drowsiness (most common)
- Low blood pressure / dizziness
- Fatigue
- Headache
- Dry mouth
- Constipation
- Stomach upset
- Decreased heart rate
Call us if you notice
- Significant blood pressure drop (fainting)
- Very slow heart rate
- Severe sedation
- Rebound hypertension if stopped abruptly
- Allergic reaction
Sedation is the most common complaint and often improves after the first 1–2 weeks. Bedtime dosing can be helpful when sedation is problematic. Never stop abruptly — blood pressure can rebound. Do not take with high-fat meals.
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Tips for Success
Evening DosingIf sedation is a problem, evening dosing uses the sleepiness beneficially.
Avoid High-Fat MealsDo not take with a high-fat meal — it significantly increases absorption and side effects.
Don't Stop AbruptlyAlways taper — stopping suddenly can cause rebound high blood pressure.
Rise SlowlyGuanfacine lowers blood pressure — stand up slowly to avoid dizziness.
Monitor BP at HomeA home blood pressure cuff can help track cardiovascular response.
Sedation ImprovesDrowsiness typically improves significantly after the first 1–2 weeks.
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Important Safety Information
Blood Pressure Effects: Guanfacine lowers blood pressure and heart rate. Tell your provider about any heart conditions or low blood pressure. Check blood pressure regularly. Rise slowly to avoid dizziness and falls.
Do Not Stop Abruptly: Stopping guanfacine suddenly can cause rebound hypertension (dangerous spike in blood pressure). Always taper the dose slowly with your provider guidance.
Sedation Warning: Guanfacine causes significant drowsiness. Use caution when driving or operating machinery until you know how it affects you — especially in the first few weeks.
Drug Interactions: Interacts with other blood pressure medications, CNS depressants, and CYP3A4 inhibitors. Always share your full medication list.
Pregnancy: Discuss risks and benefits with your provider.
Questions? I am here.
Reach me between appointments if you have concerns about side effects, notice mood changes, or have questions about your medication.
360-389-3712
info@rootedmindspsychiatry.com