Guanfacine

TENEX

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Pronunciation: GWAHN-fa-seen

Guanfacine ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Guanfacine ballicule

Guanfacine TENEX mascot mnemonic cartoon — Visual mnemonic: Guanfacine mascot
**“Gun facing Ten X’s”**
Orange plus signs → α2 agonist

What it isSelective alpha-2A agonist; ADHD and hypertension.

Why this oneNoncontrolled; less effective than stimulants but usable alone or added to one, and it helps comorbid tics.

What limits itSedation and hypotension are worst during titration. Abrupt withdrawal causes rebound hypertension; ER is not interchangeable with IR.

Pearls

Milder sedation and hypotension than clonidine
Hypertension: 1 mg at bedtime gives nearly full effect
Swallow ER tablets whole

Guanfacine molecular structure (skeletal formula) — Molecular structure: Guanfacine

Guanfacine prescription history

Animated chart of estimated U.S. prescriptions per year, Antihypertensives (1953–2026). Guanfacine enters in 1987 (estimated).

FDA-approved for

hypertension (1986)
ADHD (ER) (2009)

Off-label

tics
PTSD

Principal riskSedation and hypotension; rebound on abrupt withdrawal

Classes and tags

Clinical profile

Therapeutic safety burden1 / 4

Overdose danger1 / 4

Weight-gain liability0 / 4

Sedation liability1 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk1 / 4

Legacy pregnancy categoryC

Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.

FDA label

Read the full label on DailyMed ↗

NO BOXED WARNINGS

FDA dosing	Population	Start	Target	Max
Hypertension (alone or with other antihypertensives, especially thiazides)	Adults	1 mg QHS	1–2 mg QD	3 mg/day (adverse reactions increase significantly above 3 mg)

Titration If 1 mg gives inadequate result after 3–4 weeks, increase to 2 mg.

Renal Use the low end of the dosing range in renal impairment; dialysis patients can receive usual doses (poorly dialyzed).

Hepatic Undefined

Instructions

Give at bedtime to minimize somnolence
Do not stop abruptly — rebound (nervousness, anxiety, blood pressure rise) can occur 2–4 days after withdrawal

Available strengths

tab 1, 2 mg
ER tab 1, 2, 3, 4 mg

Cautions

Use with caution in severe coronary insufficiency, recent myocardial infarction, cerebrovascular disease, or chronic renal or hepatic failure
Sedation/drowsiness, especially at start; additive with other CNS depressants
Rebound on abrupt cessation (increased catecholamines, nervousness, blood pressure rise)
Postmarketing reports of mania/aggressive behavior and hallucinations in pediatric ADHD use

Adverse reactions

Dry mouth
Sedation/somnolence
Asthenia (weakness), fatigue
Dizziness
Constipation
Impotence
Headache
Skin rash with exfoliation (rare)

Pregnancy Not recommended for acute hypertension of pregnancy toxemia; effects on labor and delivery unknown.

Lactation Not known whether excreted in human milk (excreted in rat milk); use caution in nursing women.

Cost

Guanfacine (TENEX)

What pharmacies pay · NADAC 9/30/26

Strength		#/mo	generic $/mo	CostPlus
1 mg	tab	30 qd	$4.40	offered
2 mg	tab	30 qd	$8.02	offered

Other forms: Guanfacine ER (INTUNIV)

Generic entry1995

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Memory aids: interaction avatars

CYP3A4 substrate

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Self-check

Is guanfacine a controlled drug like stimulants?
No.
Are guanfacine ER and IR interchangeable?
No.