Drug · FAERS side-effect profile with label screen
Guanfacine side effects: what 7,820 FDA adverse event reports show
Drug class
Not stated in label
Brand names
Guanfacine Extended-Release
openFDA label
Who reports
7,820 reports · 59% serious · 245 with death outcome · 37% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Guanfacine extended-release tablets are indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) as monotherapy and as adjunctive therapy to stimulant medications . Guanfacine extended-release tablets .
FDA label, Indications and Usage
What it is
Guanfacine extended-release tablets, USP are a once-daily, extended-release formulation of guanfacine hydrochloride in a matrix tablet formulation for oral administration only. The chemical designation is N -amidino-2-(2,6-dichlorophenyl) acetamide monohydrochloride.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled adverse reaction 4Labeled (related wording) 1Likely indication confounding 3Reporting / coding artifact 1Lab value / disease marker 1Not in label — unassessed 30
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 961 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Macular detachment | 18 | 217.3 134.5–351.2ROR 217.8 · χ² 3,384 / p <1e-300 | 165.9 EB05 111.0 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial data cached |
| Oppositional defiant disorder | 23 | 163.9 107.6–249.6ROR 164.4 · χ² 3,355 / p <1e-300 | 137.1 EB05 96.2 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=17 · ♀ 14% (drug 37%) | no trial data cached |
| Defiant behaviour | 12 | 110.2 61.9–196.2ROR 110.3 · χ² 1,144 / p 5e-251 | 90.9 EB05 55.4 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=6 | no trial data cached |
| Self-destructive behaviour | 22 | 81.1 53.1–123.9ROR 81.4 · χ² 1,612 / p <1e-300 | 73.9 EB05 51.4 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=22 | no trial data cached |
| Choroidal effusion | 22 | 75.8 49.7–115.8ROR 76.1 · χ² 1,508 / p <1e-300 | 69.5 EB05 48.4 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=22 · ♀ 100% (drug 37%) · 100% clinician | no trial data cached |
| Negativism | 19 | 68.5 43.5–108.0ROR 68.7 · χ² 1,168 / p 3e-256 | 62.8 EB05 42.5 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=9 | no trial data cached |
| Disturbance in social behaviour | 59 | 68.5 52.9–88.6ROR 69.0 · χ² 3,759 / p <1e-300 | 65.4 EB05 52.6 · IC025 +5.0 3/3 methods agree | Reporting / coding artifact | serious n=18 · ♀ 14% (drug 37%) · 74% consumer | no trial data cached |
| Educational problem | 37 | 60.4 43.7–83.6ROR 60.7 · χ² 2,057 / p <1e-300 | 57.4 EB05 43.5 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=20 | no trial data cached |
| Hypertensive urgency | 11 | 58.5 32.2–106.3ROR 58.6 · χ² 553 / p 1e-122 | 52.4 EB05 31.2 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Impulsive behaviour | 77 | 56.1 44.8–70.2ROR 56.7 · χ² 4,028 / p <1e-300 | 54.3 EB05 44.8 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=39 | no trial data cached |
| Tic | 112 | 56.1 46.6–67.6ROR 56.9 · χ² 5,883 / p <1e-300 | 54.5 EB05 46.5 · IC025 +5.2 3/3 methods agree | Labeled adverse reaction exact term | serious n=62 | no trial data cached |
| Trichotillomania | 10 | 46.2 24.7–86.3ROR 46.3 · χ² 392 / p 2e-87 | 42.1 EB05 24.4 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=4 | no trial data cached |
| Oromandibular dystonia | 12 | 45.3 25.6–80.2ROR 45.4 · χ² 469 / p 3e-104 | 41.8 EB05 25.5 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Nephrogenic diabetes insipidus | 19 | 45.0 28.6–70.7ROR 45.1 · χ² 761 / p 1e-167 | 42.5 EB05 28.8 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| Distractibility | 17 | 40.1 24.9–64.7ROR 40.2 · χ² 600 / p 7e-133 | 38.0 EB05 25.1 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Orthostatic intolerance | 10 | 38.1 20.4–71.1ROR 38.1 · χ² 320 / p 6e-72 | 35.3 EB05 20.4 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=9 | no trial data cached |
| Drug dose titration not performed | 24 | 37.9 25.3–56.6ROR 38.0 · χ² 813 / p 3e-179 | 36.4 EB05 25.7 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Serous retinal detachment | 11 | 37.6 20.7–68.1ROR 37.6 · χ² 351 / p 1e-78 | 35.0 EB05 20.8 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Sinus arrhythmia | 17 | 35.4 21.9–57.1ROR 35.5 · χ² 527 / p 6e-117 | 33.7 EB05 22.3 · IC025 +3.3 3/3 methods agree | Labeled adverse reaction exact term | serious n=17 | no trial data cached |
| Brugada syndrome | 12 | 31.8 18.0–56.1ROR 31.8 · χ² 324 / p 1e-72 | 30.1 EB05 18.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Bradypnoea | 28 | 28.2 19.5–40.9ROR 28.3 · χ² 701 / p 8e-155 | 27.5 EB05 20.0 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 73% (drug 37%) · 100% clinician | no trial data cached |
| Behaviour disorder | 54 | 27.5 21.1–36.0ROR 27.7 · χ² 1,341 / p 5e-294 | 27.0 EB05 21.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=39 · ♀ 16% (drug 37%) | no trial data cached |
| Attention deficit/hyperactivity disorder | 32 | 26.5 18.7–37.5ROR 26.6 · χ² 751 / p 1e-165 | 25.9 EB05 19.2 · IC025 +3.6 3/3 methods agree | Likely indication confounding term in indications | serious n=21 · ♀ 11% (drug 37%) | no trial data cached |
| Sinus arrest | 15 | 26.2 15.8–43.6ROR 26.3 · χ² 336 / p 2e-75 | 25.2 EB05 16.2 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial data cached |
| Autism spectrum disorder | 53 | 26.2 20.0–34.3ROR 26.4 · χ² 1,249 / p 8e-274 | 25.8 EB05 20.5 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=51 | no trial data cached |
| Attention deficit hyperactivity disorder | 40 | 26.1 –ROR 26.2 · χ² – | – | Likely indication confounding term in indications | serious n=36 | no trial data cached |
| Enuresis | 37 | 24.8 17.9–34.2ROR 24.9 · χ² 813 / p 4e-179 | 24.3 EB05 18.4 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious n=26 | no trial data cached |
| Distributive shock | 20 | 24.5 15.8–38.0ROR 24.5 · χ² 423 / p 2e-94 | 23.8 EB05 16.2 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=20 · 100% clinician | no trial data cached |
| Excessive eye blinking | 13 | 23.8 13.8–41.0ROR 23.8 · χ² 259 / p 1e-58 | 22.8 EB05 13.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=6 | no trial data cached |
| Psychomotor hyperactivity | 141 | 22.9 19.4–26.9ROR 23.3 · χ² 2,902 / p <1e-300 | 22.6 EB05 19.6 · IC025 +4.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 17.9 | no trial data cached |
| Postural orthostatic tachycardia syndrome | 11 | 22.7 12.5–41.0ROR 22.7 · χ² 205 / p 9e-47 | 21.5 EB05 12.3 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious n=8 | no trial data cached |
| Aggression | 388 | 20.9 19.0–23.0ROR 21.9 · χ² 7,288 / p <1e-300 | 20.7 EB05 19.0 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 16.9 | no trial data cached |
| Electrocardiogram t wave abnormal | 12 | 20.9 11.8–36.8ROR 20.9 · χ² 206 / p 5e-47 | 19.8 EB05 11.6 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious n=12 | no trial data cached |
| Anticholinergic syndrome | 12 | 20.3 11.5–35.9ROR 20.4 · χ² 200 / p 1e-45 | 19.3 EB05 11.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Sinus bradycardia | 72 | 20.1 15.9–25.3ROR 20.2 · χ² 1,276 / p 7e-280 | 19.8 EB05 16.3 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 20.0 · 96% clinician | no trial data cached |
| Homicidal ideation | 29 | 19.2 13.3–27.7ROR 19.3 · χ² 479 / p 2e-106 | 18.8 EB05 13.7 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=27 | no trial data cached |
| Vasoplegia syndrome | 11 | 18.4 10.2–33.2ROR 18.4 · χ² 163 / p 2e-37 | 17.1 EB05 9.3 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Electrocardiogram qt prolonged | 232 | 17.4 15.3–19.7ROR 17.9 · χ² 3,549 / p <1e-300 | 17.3 EB05 15.5 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 17.1 · 94% clinician | no trial data cached |
| Physical assault | 12 | 15.5 8.8–27.2ROR 15.5 · χ² 147 / p 3e-34 | 14.2 EB05 7.7 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Abnormal behaviour | 225 | 15.2 13.4–17.3ROR 15.6 · χ² 2,960 / p <1e-300 | 15.1 EB05 13.5 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 813 | 1.7 1.6–1.8ROR 1.7 · χ² 224 / p 5e-51 | 1.7 EB05 1.6 · IC025 +0.6 | Reporting / coding artifact | serious PRR 1.8 | no trial data cached |
| Off label use (used outside approved label) | 630 | 1.9 1.8–2.1ROR 2.0 · χ² 301 / p 9e-68 | 1.9 EB05 1.8 · IC025 +0.8 | Reporting / coding artifact | serious PRR 1.9 | no trial data cached |
| Somnolence (drowsiness) | 471 | 6.3 5.8–6.9ROR 6.6 · χ² 2,106 / p <1e-300 | 6.2 EB05 5.8 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.8 | no trial data cached |
| Aggression | 388 | 20.9 19.0–23.0ROR 21.9 · χ² 7,288 / p <1e-300 | 20.7 EB05 19.0 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 16.9 | no trial data cached |
| Fatigue (tiredness) | 351 | 1.2 1.1–1.3ROR 1.2 · χ² 13 / p 1e-4 | 1.2 EB05 1.1 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 1.2 | no trial data cached |
| Hypotension (low blood pressure) | 299 | 4.0 3.6–4.5ROR 4.1 · χ² 677 / p 2e-149 | 4.0 EB05 3.6 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.0 | no trial data cached |
| Dizziness | 291 | 1.6 1.4–1.8ROR 1.6 · χ² 61 / p 4e-15 | 1.6 EB05 1.4 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 2.1 | no trial data cached |
| Insomnia (trouble sleeping) | 288 | 2.9 2.6–3.2ROR 3.0 · χ² 360 / p 2e-80 | 2.9 EB05 2.6 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.3 | no trial data cached |
| Headache | 283 | 1.2 1.1–1.4ROR 1.2 · χ² 11 / p 6e-4 | 1.2 EB05 1.1 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 1.7 | no trial data cached |
| Bradycardia (slow heart rate) | 271 | 13.7 12.2–15.4ROR 14.2 · χ² 3,179 / p <1e-300 | 13.6 EB05 12.3 · IC025 +3.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 13.6 | no trial data cached |
| Suicidal ideation (thoughts of suicide) | 269 | 7.9 7.0–8.9ROR 8.1 · χ² 1,613 / p <1e-300 | 7.8 EB05 7.0 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.8 | no trial data cached |
| Anxiety | 267 | 2.5 2.2–2.8ROR 2.6 · χ² 244 / p 2e-55 | 2.5 EB05 2.3 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.4 | no trial data cached |
| Intentional overdose | 264 | 11.1 9.9–12.5ROR 11.5 · χ² 2,424 / p <1e-300 | 11.0 EB05 10.0 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 11.2 · ♀ 65% (drug 37%) · 90% clinician | no trial data cached |
| Nausea | 258 | 0.9 0.8–1.0ROR 0.9 · χ² 5 / p 0.017 | 0.9 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 1.1 | no trial data cached |
| Toxicity to various agents | 235 | 3.8 3.3–4.3ROR 3.8 · χ² 476 / p 9e-106 | 3.7 EB05 3.3 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 94% clinician | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Oppositional defiant disorder — n=23, PRR 163.9
- Self-destructive behaviour — n=22, PRR 81.1
- Choroidal effusion — n=22, PRR 75.8
- Educational problem — n=37, PRR 60.4
- Impulsive behaviour — n=77, PRR 56.1
- Drug dose titration not performed — n=24, PRR 37.9
- Bradypnoea — n=28, PRR 28.2
- Behaviour disorder — n=54, PRR 27.5
- Autism spectrum disorder — n=53, PRR 26.2
- Distributive shock — n=20, PRR 24.5
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Guanfacine?
In FDA FAERS, the most frequently co-reported reaction terms for Guanfacine are somnolence, aggression, fatigue, hypotension, dizziness, insomnia. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Guanfacine have an FDA boxed warning?
No. The FDA label retrieved for Guanfacine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Guanfacine causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 07797c4a-a799-436b-a77c-a2861a811a99, effective 20230523; matched on
openfda.generic_name.exact:"GUANFACINE") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 1,001 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.