# Intuniv

### (guanfacine ER)

<table border="1" id="bkmrk-prescribing-info" style="border-collapse: collapse; width: 100%; border-width: 0px; background-color: rgb(230, 126, 35);"><tbody><tr><td style="background-color: rgb(194, 224, 244); border-width: 0px; width: 50%;">[**Full Prescribing Information**](https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b972af81-3a37-40be-9fe1-3ddf59852528&amp;type=display)</td><td class="align-right" style="background-color: rgb(251, 238, 184); border-width: 0px; width: 50%;">[**DailyMed Drug Information**](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=b972af81-3a37-40be-9fe1-3ddf59852528)</td></tr></tbody></table>

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**Forms/Strengths**

- **Tablets:** 1 mg, 2 mg, 3 mg, 4 mg

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### **Dosing**

- **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

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### **Quick Facts**

- 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

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### **Indications**

- ADHD** (ICD-10: F90.0)

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### **Off-Label Uses**

- **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.

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### **How to Take**

- 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**.

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### **Side Effects**

- <div class="undefined brandable--article-paragraph-title"><div class="src_paragraph_p__y9RVL ask_oe_light_with_citations_paragraph_p__6oofJ"><span class="MuiTypography-root MuiTypography-serif mui-style-1vritj8">Common: Sedation, somnolence, headache, abdominal pain, hypotension, bradycardia.</span></div><div class="src_paragraph_p__y9RVL ask_oe_light_with_citations_paragraph_p__6oofJ"><span class="MuiTypography-root MuiTypography-serif mui-style-1vritj8">Serious: Syncope, rebound hypertension, cardiac conduction abnormalitie</span></div></div>

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### **Monitoring / Labs**

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

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### **Education**

- **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**.

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### **Additional Information**

- **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.