guanfacine

Adjunctive therapy

Brands: TENEX

Last reviewed 2025-12-30

Reviewed by PsychMed Editorial Team.

View details

Quick answers

What is guanfacine?
Guanfacine (brand Tenex; immediate-release tablets) is a centrally acting alpha-2 adrenergic agonist approved for hypertension (label). In psychiatric settings it is sometimes used off-label as an adjunct when symptoms include hyperarousal, irritability, or anxiety-related sleep disruption and reducing sympathetic activation is part of the treatment goal.
What is TENEX?
TENEX is a brand name for guanfacine.
What is TENEX (guanfacine) used for?
Label indications include: Hypertension (label). Off-label use occurs for ADHD symptoms and hyperarousal (practice pattern).
What drug class is TENEX (guanfacine)?
Alpha-2A adrenergic agonist (centrally acting antihypertensive; sometimes used off-label as a psychiatric adjunct).
What strengths does TENEX (guanfacine) come in?
Immediate-release oral tablets: 1 mg, 2 mg (label).

Snapshot

Primary label indications include: Hypertension (label).
Class: Adjunctive therapy
Common US brands: TENEX
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2025-12-30

Label indications

Hypertension (label). Off-label use occurs for ADHD symptoms and hyperarousal (practice pattern).

View labelExact

Clinical Highlights

Guanfacine (brand Tenex; immediate-release tablets) is a centrally acting alpha-2 adrenergic agonist approved for hypertension (label). In psychiatric settings it is sometimes used off-label as an adjunct when symptoms include hyperarousal, irritability, or anxiety-related sleep disruption and reducing sympathetic activation is part of the treatment goal. Compared with clonidine, guanfacine is generally considered more selective for alpha-2A receptors and often feels less sedating for many patients, though fatigue and dizziness can still limit use—especially early in treatment or with polypharmacy (label/class).

The main safety limits are hypotension, bradycardia, dizziness, and sedation. Because it lowers blood pressure and heart rate, baseline and follow-up vitals are typically more important than with many “as needed” anxiety adjuncts (label).
Abrupt discontinuation can cause rebound hypertension and agitation. When rebound occurs, it may be delayed by a few days (reported 2–4 days after stopping), so tapering plans and refill continuity matter (label).
Guanfacine is not a first-line stand-alone medication for chronic anxiety disorders. Best fit is usually an adjunct role when paired with primary anxiety or mood treatments (psychotherapy and/or SSRI/SNRI strategies) (clinical practice pattern).
The compare view, guanfacine evidence feed, and guanfacine print page can support counseling and shared decision-making, especially when weighing autonomic-targeted options.
Distinguish immediate-release guanfacine from guanfacine ER (Intuniv): they are not interchangeable milligram-for-milligram, and the ER formulation is the product specifically studied and labeled for ADHD (label/guidelines).

Dosing & Formulations

Tablets: 1 mg, 2 mg (label). Hypertension labeling: 1 mg once daily at bedtime to minimize somnolence; if response is inadequate after 3–4 weeks, 2 mg once daily may be used (label).

For off-label psychiatric use, clinicians often start low, use bedtime dosing when sedation is desired, and individualize dose changes to blood pressure/heart rate and next-day functioning rather than titrating aggressively (clinical practice pattern).
If discontinuing after regular use, gradual tapering is commonly used to reduce rebound hypertension and agitation (label/class).
Avoid adding multiple sedatives to “treat” sedation; if daytime impairment emerges, dose reduction or switching agents is usually safer than stacking CNS depressants.

Monitoring & Risks

Blood pressure and heart rate: typically checked at baseline and during titration; counsel about dizziness and orthostasis (label). Sedation and impaired alertness can occur, especially early and with other sedatives; reassess driving/occupational safety during dose changes (label/class).

Rebound risk: missing doses or abrupt discontinuation can trigger blood pressure elevation and agitation; rebound may be delayed, so patients can worsen several days after stopping (label).
In patients with baseline low blood pressure, falls risk, or multiple antihypertensives, guanfacine is often used cautiously or avoided because small dose changes can have outsized functional effects.

Drug Interactions

Additive hypotension or bradycardia can occur with other antihypertensives; symptomatic dizziness or syncope should prompt review of the full regimen (label/class). Additive sedation can occur with alcohol and other CNS depressants, including sedating antipsychotics, hypnotics, and opioids; total sedative burden is a major driver of harm (label/class).

Enzyme-inducing medications have been reported to reduce guanfacine exposure and half-life in some patients; if efficacy drops after adding an inducer, reassess dosing and alternatives rather than “dose chasing” without monitoring (label).

Practice Notes

Guanfacine is most often used as an adjunct when physical anxiety symptoms (autonomic arousal) or hyperarousal-linked insomnia is a major treatment target, rather than as a primary long-term anxiety strategy. When insomnia is the main target, compare guanfacine with alternatives that do not lower blood pressure (e.g., DORAs, ramelteon, low-dose doxepin) and choose based on comorbidity and safety profile.

Document a taper plan early, especially when care transitions are likely, to reduce the chance of abrupt discontinuation and rebound hypertension.
If ADHD symptoms are being targeted, consider whether guanfacine ER (Intuniv) is a better fit than immediate-release guanfacine based on guideline positioning and product labeling.

References

Guanfacine tablets prescribing information — DailyMed (2025)
Attention deficit hyperactivity disorder (NICE guideline NG87) — NICE (2018)
Clinical Practice Guideline FOR THE Diagnosis, Evaluation, AND Treatment OF Attention Deficit/hyperactivity Disorder IN Children AND Adolescents — Pediatrics (2019)
Comparative Efficacy AND Tolerability OF Medications FOR Adhd (systematic Review AND Network Meta Analysis) — Lancet Psychiatry (2018)