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guanfacine ER

Adjunctive therapy

Brand: INTUNIV

Published 2025-12-22 · Last reviewed 2025-12-29 · 4 references

Content sourced from FDA labeling (DailyMed) and peer-reviewed literature.

Print sheet Review evidence

At a glance

Class: Adjunctive therapy·Typical dose: Typically once daily. Morning dosing is common, but bedtime dosing can be considered when sedation is prominent.·Half-life: Single-dose mean 17 h; Single-dose range 10–30 h·LAI available: No

Class: Adjunctive therapy
Typical dose: Typically once daily. Morning dosing is common, but bedtime dosing can be considered when sedation is prominent.
Half-life: Single-dose mean 17 h; Single-dose range 10–30 h
LAI available: No

Quick answers

What is guanfacine ER?: Guanfacine extended-release (brand Intuniv) is a non-stimulant ADHD medication and an alpha-2A adrenergic agonist. It is often used when stimulants are poorly tolerated, when tics/anxiety/insomnia complicate stimulant use, or as an adjunct to stimulants for residual impulsivity.
What is INTUNIV?: INTUNIV is a brand name for guanfacine ER.
What is INTUNIV (guanfacine ER) used for?: Label indications include: Attention-deficit/hyperactivity disorder (ADHD) (extended-release formulation; product-dependent).
What drug class is INTUNIV (guanfacine ER)?: Non-Stimulant ADHD.
What is the mechanism of action of INTUNIV (guanfacine ER)?: Alpha-2A adrenergic agonist (non-stimulant ADHD medication).
What strengths does INTUNIV (guanfacine ER) come in?: Extended-release oral tablets (once-daily).

General information

Guanfacine extended-release (ER) is a non-stimulant ADHD medication and an alpha-2A adrenergic agonist. It is often used when stimulants are poorly tolerated or when tics, anxiety, insomnia, or diversion concerns complicate stimulant prescribing.

It is sometimes used as an adjunct to stimulants when focus improves but residual impulsivity, emotional reactivity, or sleep-onset problems remain prominent.

When combined with stimulants, guanfacine ER is often used to target hyperactivity, impulsivity, and evening rebound while allowing lower stimulant doses in patients who develop insomnia or anxiety.

In serious mental illness, guanfacine ER may be appealing when stimulant activation risk is high, but hypotension, bradycardia, and additive sedation with other CNS depressants remain key monitoring targets.

The guanfacine ER compare view, the evidence feed, and the print page support side-by-side review and patient-friendly handouts for titration and tapering.

U.S. approvals

Attention-deficit/hyperactivity disorder (ADHD) (extended-release formulation; product-dependent)

Formulations & strengths

Extended-release oral tablets (once-daily).

Generic availability

Widely available generically.

The most common reasons guanfacine ER fails are sedation that is not managed with dosing timing/titration speed and discontinuation without a taper (rebound symptoms). When used thoughtfully, it can reduce hyperactivity and impulsivity while supporting sleep and reducing the need for higher stimulant doses.

View labelExact

Mechanism of action

Refer to the Glossary entry on Neurotransmitters for background on receptor systems involved in serious mental illness.

Alpha-2A adrenergic agonism reduces noradrenergic signaling in prefrontal circuits and can improve working memory, impulse control, and emotional regulation.

Unlike stimulants, it does not directly increase dopamine release and has no meaningful euphoric effect; misuse risk is lower.

Sedation and hypotension reflect central and peripheral alpha-2 effects; titration speed and dose timing are practical levers to improve tolerability.

Alpha-2A adrenergic agonist (primary).
No direct stimulant release mechanism; not a controlled substance.

Metabolism & pharmacokinetics

Metabolized primarily via CYP3A4; inhibitors can increase exposure and adverse effects.
Half-life is long enough for once-daily dosing; clinical sedation often tracks peak exposure early in treatment.
Renal/hepatic impairment and interacting medications can increase hypotension and fatigue risk.

Dosing & administration

Typically once daily. Morning dosing is common, but bedtime dosing can be considered when sedation is prominent.
Dosing typically starts low and titrates weekly as tolerated. Typical doses are 1–4 mg/day (product- and age-dependent).
If daytime fatigue or dizziness limits function, slower titration, dose reduction, or evening dosing are common adjustments before concluding the trial is not tolerated.
Abrupt discontinuation can lead to rebound hypertension, tachycardia, and irritability; a taper is typically used to reduce this risk.

Monitoring & labs

Baseline and periodic blood pressure and heart rate, especially during titration.
Sedation, dizziness, and orthostasis are commonly monitored; dose timing and titration speed are adjusted as needed.
Interacting medications (CYP3A4 inhibitors/inducers) and other sedatives are typically reviewed.
Taper planning in advance can reduce rebound hypertension and irritability.

Sources: DailyMed label; guideline statements; network meta-analysis context.

Adverse effects

FDA boxed warnings

Common side effects (≥10%)

Sedation / fatigue: Common early; slow titration and consider bedtime dosing if limiting.
Dizziness / orthostasis: Related to hypotension; counseling often covers slow position changes and periodic vitals checks.
Bradycardia / hypotension: Heart rate and blood pressure are commonly monitored during titration; caution is warranted with other antihypertensives.
Dry mouth / constipation: Anticholinergic-like symptoms can occur; hydration and bowel-regimen strategies are often discussed as needed.

Other notable effects

Rebound hypertension and agitation can occur with abrupt discontinuation; taper planning in advance can reduce this risk.
Additive sedation can occur when combined with other CNS depressants; driving and occupational safety is often revisited.

Interactions

CYP3A4 inhibitors can increase exposure and worsen hypotension/sedation; CYP3A4 inducers may reduce efficacy.
Additive hypotension or sedation can occur with other antihypertensives and CNS depressants (including alcohol).

Other useful information

Guanfacine ER is often considered when stimulants improve focus but impulsivity or emotional reactivity remains problematic, or when tics/anxiety limit stimulant dose.
When sedation is the main adverse effect, slower titration and dose-timing adjustments are common first steps rather than adding stimulants back solely to counter fatigue.
Baseline blood pressure and heart rate are commonly documented and revisited after each dose change.
In polypharmacy (e.g., multiple sedating agents or antihypertensives), a single taper plan is often documented and communicated across care transitions to reduce abrupt discontinuation and rebound symptoms.

References

Related hubs:SMI toolkit·Support resources