Clonidine Transdermal System side effects: what 2,071 FDA adverse event reports show
Drug class
Central alpha-2 Adrenergic Agonist
Who reports
2,071 reports · 27% serious · 61 with death outcome · 67% female
Used for
Clonidine Transdermal System, USP is indicated in the treatment of hypertension. It may be employed alone or concomitantly with other antihypertensive agents.
What it is
DESCRIPTION Clonidine Transdermal System, USP provides continuous systemic delivery of clonidine for 7 days at an approximately constant rate. Clonidine is a centrally acting alpha‑agonist hypotensive agent.
Boxed warning
None in the current label
Causality screen of the 26 strongest signals
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. 22 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Application site pruritus | 343 | 155.4 140.9–171.3ROR 186.0 · χ² 51,703 / p <1e-300 | 151.7 EB05 138.7 · IC025 +6.8 3/3 methods agree | Not in label — unassessed | serious n=29 · 84% consumer | no trial data cached |
| Application site rash | 195 | 145.1 126.9–166.1ROR 160.1 · χ² 27,390 / p <1e-300 | 141.1 EB05 125.3 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=17 · 73% consumer | no trial data cached |
| Application site erythema | 301 | 117.1 105.5–130.1ROR 136.9 · χ² 34,189 / p <1e-300 | 115.0 EB05 104.5 · IC025 +6.4 3/3 methods agree | Not in label — unassessed | serious n=20 · 85% consumer | no trial data cached |
| Application site irritation | 120 | 98.6 82.8–117.4ROR 104.6 · χ² 11,388 / p <1e-300 | 96.2 EB05 82.6 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=5 · 79% consumer | no trial data cached |
| Product adhesion issue | 164 | 47.0 40.6–54.5ROR 51.0 · χ² 7,324 / p <1e-300 | 46.6 EB05 40.9 · IC025 +5.1 3/3 methods agree | Reporting / coding artifact | serious n=17 · 88% consumer | no trial data cached |
| Application site pain | 81 | 37.4 30.2–46.3ROR 38.9 · χ² 2,824 / p <1e-300 | 37.0 EB05 30.7 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=4 · 81% consumer | no trial data cached |
| Blood pressure increased | 251 | 16.6 14.8–18.7ROR 18.8 · χ² 3,688 / p <1e-300 | 16.6 EB05 14.9 · IC025 +3.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 17.0 · 73% consumer | no trial data cached |
| Dermatitis contact | 16 | 14.3 8.8–23.3ROR 14.4 · χ² 184 / p 3e-42 | 13.4 EB05 8.1 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious n=1 | no trial data cached |
| Blood pressure fluctuation | 30 | 12.6 8.9–18.0ROR 12.8 · χ² 310 / p 1e-69 | 12.2 EB05 8.6 · IC025 +2.8 3/3 methods agree | Lab value / disease marker | serious PRR 10.2 · 76% consumer | no trial data cached |
| Product packaging quantity issue | 11 | 10.2 5.7–18.4ROR 10.3 · χ² 82 / p 6e-20 | 8.3 EB05 4.6 · IC025 +1.8 3/3 methods agree | Reporting / coding artifact | serious n=1 | no trial data cached |
| Blood pressure systolic increased | 18 | 9.3 5.9–14.7ROR 9.4 · χ² 125 / p 2e-29 | 8.1 EB05 5.2 · IC025 +2.1 3/3 methods agree | Lab value / disease marker | serious PRR 15.6 | no trial data cached |
| Blood pressure abnormal | 17 | 8.7 5.4–14.0ROR 8.8 · χ² 108 / p 1e-25 | 7.5 EB05 4.8 · IC025 +2.0 3/3 methods agree | Lab value / disease marker | serious PRR 6.3 | no trial data cached |
| Scar | 14 | 8.3 4.9–13.9ROR 8.3 · χ² 82 / p 6e-20 | 6.9 EB05 4.2 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 11.6 | no trial data cached |
| Drug effect decreased | 37 | 6.9 5.0–9.4ROR 7.0 · χ² 180 / p 3e-41 | 6.4 EB05 4.8 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 6.8 · 72% consumer | no trial data cached |
| Hypertension (high blood pressure) | 143 | 6.8 5.8–8.0ROR 7.3 · χ² 713 / p 2e-157 | 6.7 EB05 5.8 · IC025 +2.5 3/3 methods agree | Likely indication confounding term in indications | serious PRR 8.9 | no trial data cached |
| Product quality issue | 82 | 6.2 5.0–7.6ROR 6.4 · χ² 351 / p 1e-78 | 6.0 EB05 5.0 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 9.4 · 85% consumer | no trial data cached |
| Blood pressure decreased | 35 | 5.3 3.8–7.4ROR 5.4 · χ² 120 / p 4e-28 | 5.0 EB05 3.8 · IC025 +1.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.8 · 77% consumer | no trial data cached |
| Pharmaceutical product complaint | 13 | 5.0 2.9–8.6ROR 5.0 · χ² 38 / p 4e-10 | 4.3 EB05 2.7 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 13.2 | no trial data cached |
| Wrong technique in product usage process | 95 | 4.8 3.9–5.8ROR 4.9 · χ² 281 / p 2e-63 | 4.7 EB05 3.9 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious PRR 6.5 · 87% consumer | no trial data cached |
| Medication error | 26 | 4.7 3.2–7.0ROR 4.8 · χ² 73 / p 6e-18 | 4.4 EB05 3.2 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | serious PRR 9.4 | no trial data cached |
| Heart rate decreased | 16 | 4.6 2.8–7.5ROR 4.6 · χ² 41 / p 6e-11 | 4.1 EB05 2.7 · IC025 +1.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.6 | no trial data cached |
| Skin irritation | 20 | 4.4 2.9–6.8ROR 4.4 · χ² 50 / p 1e-12 | 4.0 EB05 2.8 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious n=1 | no trial data cached |
| Renal failure acute | 18 | 4.2 2.7–6.7ROR 4.3 · χ² 41 / p 6e-11 | 3.9 EB05 2.6 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 9.1 | no trial data cached |
| Sedation | 10 | 3.9 2.1–7.2ROR 3.9 · χ² 19 / p 8e-6 | 3.4 EB05 2.0 · IC025 +0.7 | Labeled adverse reaction exact term | serious PRR 5.7 | no trial data cached |
| Product substitution issue | 17 | 3.0 1.9–4.8ROR 3.0 · χ² 21 / p 3e-6 | 2.8 EB05 1.9 · IC025 +0.7 | Reporting / coding artifact | serious PRR 8.8 | no trial data cached |
| Withdrawal syndrome | 10 | 2.4 1.3–4.5ROR 2.4 · χ² 7 / p 0.004 | 2.3 EB05 1.3 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 5.2 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 |
|---|---|---|---|---|---|---|
| Application site pruritus | 343 | 155.4 140.9–171.3ROR 186.0 · χ² 51,703 / p <1e-300 | 151.7 EB05 138.7 · IC025 +6.8 3/3 methods agree | Not in label — unassessed | serious n=29 · 84% consumer | no trial data cached |
| Application site erythema | 301 | 117.1 105.5–130.1ROR 136.9 · χ² 34,189 / p <1e-300 | 115.0 EB05 104.5 · IC025 +6.4 3/3 methods agree | Not in label — unassessed | serious n=20 · 85% consumer | no trial data cached |
| Blood pressure increased | 251 | 16.6 14.8–18.7ROR 18.8 · χ² 3,688 / p <1e-300 | 16.6 EB05 14.9 · IC025 +3.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 17.0 · 73% consumer | no trial data cached |
| Application site rash | 195 | 145.1 126.9–166.1ROR 160.1 · χ² 27,390 / p <1e-300 | 141.1 EB05 125.3 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=17 · 73% consumer | no trial data cached |
| Product adhesion issue | 164 | 47.0 40.6–54.5ROR 51.0 · χ² 7,324 / p <1e-300 | 46.6 EB05 40.9 · IC025 +5.1 3/3 methods agree | Reporting / coding artifact | serious n=17 · 88% consumer | no trial data cached |
| Hypertension (high blood pressure) | 143 | 6.8 5.8–8.0ROR 7.3 · χ² 713 / p 2e-157 | 6.7 EB05 5.8 · IC025 +2.5 3/3 methods agree | Likely indication confounding term in indications | serious PRR 8.9 | no trial data cached |
| Application site irritation | 120 | 98.6 82.8–117.4ROR 104.6 · χ² 11,388 / p <1e-300 | 96.2 EB05 82.6 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=5 · 79% consumer | no trial data cached |
| Wrong technique in product usage process | 95 | 4.8 3.9–5.8ROR 4.9 · χ² 281 / p 2e-63 | 4.7 EB05 3.9 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious PRR 6.5 · 87% consumer | no trial data cached |
| Product quality issue | 82 | 6.2 5.0–7.6ROR 6.4 · χ² 351 / p 1e-78 | 6.0 EB05 5.0 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 9.4 · 85% consumer | no trial data cached |
| Application site pain | 81 | 37.4 30.2–46.3ROR 38.9 · χ² 2,824 / p <1e-300 | 37.0 EB05 30.7 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=4 · 81% consumer | no trial data cached |
| Drug effect decreased | 37 | 6.9 5.0–9.4ROR 7.0 · χ² 180 / p 3e-41 | 6.4 EB05 4.8 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 6.8 · 72% consumer | no trial data cached |
| Blood pressure decreased | 35 | 5.3 3.8–7.4ROR 5.4 · χ² 120 / p 4e-28 | 5.0 EB05 3.8 · IC025 +1.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.8 · 77% consumer | no trial data cached |
| Blood pressure fluctuation | 30 | 12.6 8.9–18.0ROR 12.8 · χ² 310 / p 1e-69 | 12.2 EB05 8.6 · IC025 +2.8 3/3 methods agree | Lab value / disease marker | serious PRR 10.2 · 76% consumer | no trial data cached |
| Medication error | 26 | 4.7 3.2–7.0ROR 4.8 · χ² 73 / p 6e-18 | 4.4 EB05 3.2 · IC025 +1.5 3/3 methods agree | Reporting / coding artifact | serious PRR 9.4 | no trial data cached |
| Skin irritation | 20 | 4.4 2.9–6.8ROR 4.4 · χ² 50 / p 1e-12 | 4.0 EB05 2.8 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious n=1 | 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.
- Application site pruritus — n=343, PRR 155.4
- Application site rash — n=195, PRR 145.1
- Application site erythema — n=301, PRR 117.1
- Application site irritation — n=120, PRR 98.6
- Application site pain — n=81, PRR 37.4
- Skin irritation — n=20, PRR 4.4
✓ A hand-written Bradford Hill causality assessment exists for this drug: Clonidine ↔ Rebound hypertension / withdrawal syndrome.
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 Clonidine Transdermal System?
In FDA FAERS, the most frequently co-reported reaction terms for Clonidine Transdermal System are application site pruritus, application site erythema, blood pressure increased, application site rash, hypertension, application site irritation. 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 Clonidine Transdermal System have an FDA boxed warning?
No. The FDA label retrieved for Clonidine Transdermal System has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Clonidine Transdermal System 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 0fcfcdb5-0662-41d9-919b-c66d4f4f0c8b, effective 20260330; matched on
openfda.generic_name.exact:"CLONIDINE TRANSDERMAL SYSTEM") - 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, 48 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.