Drug · FAERS side-effect profile with label screen
Gaunfacine side effects: what 3,596 FDA adverse event reports show
Drug class
Not stated in label
Brand names
Guanfacine
openFDA label
Who reports
3,596 reports · 56% serious · 172 with death outcome · 40% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Guanfacine Tablets, USP are indicated in the management of hypertension. Guanfacine hydrochloride may be given alone or in combination with other antihypertensive agents, especially thiazide-type diuretics.
FDA label, Indications and Usage
What it is
DESCRIPTION Guanfacine Tablets, USP are a centrally acting antihypertensive with α 2 -adrenoceptor agonist properties in tablet form for oral administration.
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) 1Reporting / coding artifact 7Not in label — unassessed 28
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.
- 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.
- 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. 151 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 |
|---|---|---|---|---|---|---|
| Sinus bradycardia | 49 | 29.6 22.4–39.1ROR 30.0 · χ² 1,320 / p 2e-289 | 29.2 EB05 22.9 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 31.4 · 96% clinician | no trial data cached |
| Aggression | 185 | 21.6 18.7–24.8ROR 22.7 · χ² 3,603 / p <1e-300 | 21.4 EB05 19.0 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious PRR 18.5 · ♀ 18% (drug 40%) | no trial data cached |
| Psychomotor hyperactivity | 61 | 21.4 16.7–27.5ROR 21.7 · χ² 1,162 / p 5e-255 | 21.2 EB05 17.1 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 20.4 · ♀ 11% (drug 40%) | no trial data cached |
| Serotonin syndrome | 52 | 15.9 12.1–20.8ROR 16.1 · χ² 709 / p 2e-156 | 15.7 EB05 12.4 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 16.5 · ♀ 67% (drug 40%) · 100% clinician | no trial data cached |
| Intentional overdose | 148 | 13.6 11.6–15.9ROR 14.1 · χ² 1,710 / p <1e-300 | 13.5 EB05 11.7 · IC025 +3.4 3/3 methods agree | Reporting / coding artifact | serious PRR 14.5 · ♀ 63% (drug 40%) · 96% clinician | no trial data cached |
| Bradycardia (slow heart rate) | 121 | 13.3 11.2–15.8ROR 13.7 · χ² 1,364 / p 7e-299 | 13.2 EB05 11.3 · IC025 +3.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 13.8 · 95% clinician | no trial data cached |
| Abnormal behaviour | 88 | 12.9 10.5–15.8ROR 13.2 · χ² 952 / p 2e-209 | 12.7 EB05 10.6 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.4 | no trial data cached |
| Intentional self-injury | 44 | 12.7 9.5–17.1ROR 12.9 · χ² 463 / p 4e-103 | 12.4 EB05 9.5 · IC025 +3.0 3/3 methods agree | Reporting / coding artifact | serious PRR 13.3 | no trial data cached |
| Dystonia | 41 | 12.3 9.1–16.7ROR 12.4 · χ² 414 / p 3e-92 | 11.9 EB05 9.0 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 13.0 · ♀ 11% (drug 40%) · 97% clinician | no trial data cached |
| Anger | 71 | 12.2 9.7–15.4ROR 12.4 · χ² 719 / p 1e-158 | 12.0 EB05 9.8 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 | no trial data cached |
| Sedation | 50 | 11.2 8.5–14.7ROR 11.3 · χ² 454 / p 6e-101 | 10.8 EB05 8.4 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.9 | no trial data cached |
| Neuroleptic malignant syndrome | 22 | 10.8 7.1–16.4ROR 10.9 · χ² 186 / p 1e-42 | 9.9 EB05 6.6 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 11.2 | no trial data cached |
| Electrocardiogram qt prolonged | 66 | 10.7 8.4–13.6ROR 10.9 · χ² 571 / p 2e-126 | 10.4 EB05 8.4 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 11.2 · 98% clinician | no trial data cached |
| Respiratory depression | 22 | 10.5 6.9–15.9ROR 10.5 · χ² 179 / p 4e-41 | 9.5 EB05 6.3 · IC025 +2.4 3/3 methods agree | Labeled (related wording) related wording | serious PRR 11.1 · 100% clinician | no trial data cached |
| Affect lability | 17 | 10.3 6.4–16.5ROR 10.3 · χ² 133 / p 5e-31 | 9.0 EB05 5.6 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 10.4 | no trial data cached |
| Product substitution issue | 99 | 10.0 8.3–12.2ROR 10.3 · χ² 797 / p 1e-175 | 9.8 EB05 8.3 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 10.5 · 72% consumer | no trial data cached |
| Irritability | 98 | 9.5 7.8–11.5ROR 9.7 · χ² 737 / p 1e-162 | 9.3 EB05 7.8 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.6 | no trial data cached |
| Mania | 26 | 9.2 6.3–13.5ROR 9.3 · χ² 183 / p 7e-42 | 8.4 EB05 5.9 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 · ♀ 64% (drug 40%) | no trial data cached |
| Agitation | 115 | 9.1 7.6–10.9ROR 9.4 · χ² 824 / p 2e-181 | 8.9 EB05 7.6 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.2 · ♀ 18% (drug 40%) | no trial data cached |
| Device mechanical issue | 20 | 9.0 5.8–14.0ROR 9.1 · χ² 135 / p 2e-31 | 8.0 EB05 5.3 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Therapy change | 14 | 8.5 5.0–14.3ROR 8.5 · χ² 85 / p 2e-20 | 7.1 EB05 4.3 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious n=4 | no trial data cached |
| Orthostatic hypotension (dizziness on standing) | 25 | 8.4 5.7–12.4ROR 8.4 · χ² 155 / p 9e-36 | 7.5 EB05 5.3 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.8 · 92% clinician | no trial data cached |
| Generalised tonic-clonic seizure | 20 | 7.1 4.6–11.0ROR 7.2 · χ² 99 / p 1e-23 | 6.3 EB05 4.2 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.7 | no trial data cached |
| Rebound effect | 13 | 6.7 3.9–11.5ROR 6.7 · χ² 57 / p 2e-14 | 5.5 EB05 3.4 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 9.4 | no trial data cached |
| Hallucination, auditory | 18 | 6.6 4.2–10.5ROR 6.6 · χ² 80 / p 2e-19 | 5.7 EB05 3.8 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.4 | no trial data cached |
| Emotional disorder | 35 | 6.6 4.7–9.2ROR 6.6 · χ² 160 / p 5e-37 | 6.1 EB05 4.6 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.1 · ♀ 12% (drug 40%) | no trial data cached |
| Toxicity to various agents | 179 | 6.2 5.4–7.2ROR 6.5 · χ² 784 / p 7e-173 | 6.1 EB05 5.4 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 · 98% clinician | no trial data cached |
| Increased appetite | 20 | 6.2 4.0–9.6ROR 6.2 · χ² 82 / p 6e-20 | 5.5 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.5 | no trial data cached |
| Posterior reversible encephalopathy syndrome | 10 | 6.1 3.3–11.4ROR 6.1 · χ² 38 / p 4e-10 | 4.9 EB05 2.9 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 | no trial data cached |
| Mood swings | 33 | 6.0 4.3–8.5ROR 6.1 · χ² 134 / p 3e-31 | 5.6 EB05 4.2 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 7.3 | no trial data cached |
| Lethargy | 59 | 6.0 4.6–7.7ROR 6.1 · χ² 240 / p 2e-54 | 5.7 EB05 4.6 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Muscle rigidity | 12 | 5.9 3.3–10.3ROR 5.9 · χ² 44 / p 2e-11 | 4.9 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Salivary hypersecretion | 10 | 5.8 3.1–10.8ROR 5.8 · χ² 35 / p 1e-9 | 4.7 EB05 2.7 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.7 | no trial data cached |
| Blindness unilateral | 14 | 5.8 3.4–9.8ROR 5.8 · χ² 51 / p 5e-13 | 4.9 EB05 3.1 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Sinus tachycardia | 14 | 5.8 3.4–9.7ROR 5.8 · χ² 50 / p 6e-13 | 4.9 EB05 3.1 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.1 | no trial data cached |
| Impaired quality of life | 14 | 5.7 3.4–9.6ROR 5.7 · χ² 49 / p 1e-12 | 4.8 EB05 3.1 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 1.2 | no trial data cached |
| Bipolar disorder | 10 | 5.3 2.9–9.9ROR 5.3 · χ² 31 / p 1e-8 | 4.4 EB05 2.6 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Drug level increased | 15 | 5.3 3.2–8.8ROR 5.3 · χ² 48 / p 2e-12 | 4.6 EB05 3.0 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 4.4 | no trial data cached |
| Product physical issue | 18 | 5.3 3.3–8.3ROR 5.3 · χ² 58 / p 1e-14 | 4.7 EB05 3.1 · IC025 +1.4 3/3 methods agree | Reporting / coding artifact | serious n=2 | no trial data cached |
| Coma | 43 | 5.3 3.9–7.1ROR 5.3 · χ² 144 / p 2e-33 | 5.0 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.5 · ♀ 70% (drug 40%) · 95% clinician | 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 |
|---|---|---|---|---|---|---|
| Aggression | 185 | 21.6 18.7–24.8ROR 22.7 · χ² 3,603 / p <1e-300 | 21.4 EB05 19.0 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious PRR 18.5 · ♀ 18% (drug 40%) | no trial data cached |
| Somnolence (drowsiness) | 180 | 5.2 4.5–6.0ROR 5.4 · χ² 615 / p 4e-136 | 5.2 EB05 4.5 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 | no trial data cached |
| Toxicity to various agents | 179 | 6.2 5.4–7.2ROR 6.5 · χ² 784 / p 7e-173 | 6.1 EB05 5.4 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 · 98% clinician | no trial data cached |
| Hypotension (low blood pressure) | 158 | 4.6 3.9–5.4ROR 4.8 · χ² 445 / p 4e-99 | 4.5 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.5 · 92% clinician | no trial data cached |
| Intentional overdose | 148 | 13.6 11.6–15.9ROR 14.1 · χ² 1,710 / p <1e-300 | 13.5 EB05 11.7 · IC025 +3.4 3/3 methods agree | Reporting / coding artifact | serious PRR 14.5 · ♀ 63% (drug 40%) · 96% clinician | no trial data cached |
| Anxiety | 142 | 2.9 2.5–3.4ROR 3.0 · χ² 177 / p 9e-41 | 2.9 EB05 2.5 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.8 | no trial data cached |
| Insomnia (trouble sleeping) | 130 | 2.8 2.4–3.4ROR 2.9 · χ² 155 / p 7e-36 | 2.8 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.1 | no trial data cached |
| Drug interaction | 127 | 4.7 3.9–5.5ROR 4.8 · χ² 365 / p 1e-81 | 4.6 EB05 4.0 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious PRR 5.1 · 93% clinician | no trial data cached |
| Bradycardia (slow heart rate) | 121 | 13.3 11.2–15.8ROR 13.7 · χ² 1,364 / p 7e-299 | 13.2 EB05 11.3 · IC025 +3.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 13.8 · 95% clinician | no trial data cached |
| Agitation | 115 | 9.1 7.6–10.9ROR 9.4 · χ² 824 / p 2e-181 | 8.9 EB05 7.6 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.2 · ♀ 18% (drug 40%) | no trial data cached |
| Product substitution issue | 99 | 10.0 8.3–12.2ROR 10.3 · χ² 797 / p 1e-175 | 9.8 EB05 8.3 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 10.5 · 72% consumer | no trial data cached |
| Irritability | 98 | 9.5 7.8–11.5ROR 9.7 · χ² 737 / p 1e-162 | 9.3 EB05 7.8 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.6 | no trial data cached |
| Abnormal behaviour | 88 | 12.9 10.5–15.8ROR 13.2 · χ² 952 / p 2e-209 | 12.7 EB05 10.6 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.4 | no trial data cached |
| Overdose | 83 | 2.2 1.8–2.8ROR 2.3 · χ² 56 / p 4e-14 | 2.2 EB05 1.8 · IC025 +0.8 | Reporting / coding artifact | serious PRR 2.7 | no trial data cached |
| Suicidal ideation (thoughts of suicide) | 80 | 5.1 4.1–6.3ROR 5.2 · χ² 260 / p 1e-58 | 4.9 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 | 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.
- Sinus bradycardia — n=49, PRR 29.6
- Aggression — n=185, PRR 21.6
- Psychomotor hyperactivity — n=61, PRR 21.4
- Serotonin syndrome — n=52, PRR 15.9
- Abnormal behaviour — n=88, PRR 12.9
- Dystonia — n=41, PRR 12.3
- Anger — n=71, PRR 12.2
- Neuroleptic malignant syndrome — n=22, PRR 10.8
- Electrocardiogram qt prolonged — n=66, PRR 10.7
- Irritability — n=98, PRR 9.5
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 Gaunfacine?
In FDA FAERS, the most frequently co-reported reaction terms for Gaunfacine are aggression, somnolence, toxicity to various agents, hypotension, anxiety, 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 Gaunfacine have an FDA boxed warning?
No. The FDA label retrieved for Gaunfacine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Gaunfacine 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 00c3b4d2-fc4d-4e68-9157-eb29d927deaf, effective 20250228; matched on
openfda.generic_name.exact:"GAUNFACINE") - 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, 191 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.