Guanfacine
TENEX
What it isSelective alpha-2A agonist; ADHD and hypertension.
Why this oneUnlike stimulants, it is noncontrolled and can reduce hyperactivity, impulsivity, and comorbid tics.
What limits itSedation and hypotension are worst during titration. Abrupt withdrawal causes rebound hypertension; ER is not interchangeable with IR.
FDA-approved for
- hypertension (1986)
- ADHD (ER) (2009)
Off-label
- tics
- PTSD
FDA label
Read the full label on DailyMed ↗
| 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
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.
NO BOXED WARNINGS
Principal riskSedation and hypotension; rebound on abrupt withdrawal
Cost, est. cash$5–$150/month
Generic entry1995
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
Mechanism of action: Guanfacine ballicule
Open Guanfacine in the interactive console ↗
Memory aids: mascots and interaction avatars
Orange plus signs → α2 agonist
