Drug · FAERS side-effect profile with label screen
Oxybutynin Chloride side effects: what 8,707 FDA adverse event reports show
Drug class
Muscarinic antagonist
FDA label, Indications wording
Who reports
8,707 reports · 56% serious · 550 with death outcome · 71% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Oxybutynin chloride is a muscarinic antagonist indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and frequency. ( 1 ) Oxybutynin chloride extended-release tablets are also indicated for the treatment of pediatric patients aged 6 years and older with symptoms of detrusor overactivity associated with a neurological condition (e.g., spina bifida).
FDA label, Indications and Usage
What it is
Oxybutynin chloride extended-release tablets are an antispasmodic, muscarinic antagonist. Each oxybutynin chloride extended-release tablets contains 5 mg, 10 mg, or 15 mg of oxybutynin chloride USP, formulated as a once-a-day controlled-release tablet 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 2Labeled (related wording) 4Likely indication confounding 7Reporting / coding artifact 1Not in label — unassessed 26
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.
- 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. 1,007 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 |
|---|---|---|---|---|---|---|
| Vaginal flatulence | 114 | 1,439.3 1,141.6–1,814.7ROR 1,458.4 · χ² 101,111 / p <1e-300 | 778.4 EB05 665.6 · IC025 +7.2 3/3 methods agree | Not in label — unassessed | serious n=114 · ♀ 100% (drug 71%) | no trial data cached |
| Female genital tract fistula | 116 | 173.9 144.2–209.8ROR 176.3 · χ² 18,424 / p <1e-300 | 158.0 EB05 135.3 · IC025 +6.3 3/3 methods agree | Not in label — unassessed | serious n=116 · ♀ 100% (drug 71%) | no trial data cached |
| Radiculopathy | 120 | 114.7 95.6–137.6ROR 116.3 · χ² 12,797 / p <1e-300 | 107.6 EB05 92.4 · IC025 +5.9 3/3 methods agree | Not in label — unassessed | serious n=118 · ♀ 100% (drug 71%) | no trial data cached |
| Proctitis | 116 | 103.8 86.3–124.9ROR 105.2 · χ² 11,221 / p <1e-300 | 98.0 EB05 83.9 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=116 · ♀ 100% (drug 71%) | no trial data cached |
| Anticholinergic syndrome | 51 | 79.5 60.2–105.1ROR 80.0 · χ² 3,751 / p <1e-300 | 74.9 EB05 59.2 · IC025 +5.0 3/3 methods agree | Labeled (related wording) related wording | serious n=51 | no trial data cached |
| Chronic sinusitis | 118 | 78.2 65.2–93.9ROR 79.3 · χ² 8,637 / p <1e-300 | 74.9 EB05 64.2 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=116 · ♀ 98% (drug 71%) | no trial data cached |
| Muscular dystrophy | 11 | 61.9 34.0–112.5ROR 61.9 · χ² 584 / p 2e-129 | 54.9 EB05 32.7 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Vaginal discharge | 117 | 28.3 23.7–34.0ROR 28.7 · χ² 3,025 / p <1e-300 | 27.9 EB05 23.9 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=116 · ♀ 100% (drug 71%) | no trial data cached |
| Neurogenic bladder | 24 | 27.6 18.4–41.2ROR 27.6 · χ² 581 / p 1e-128 | 26.7 EB05 18.9 · IC025 +3.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=22 · ♀ 46% (drug 71%) | no trial data cached |
| Oral candidiasis (oral thrush) | 120 | 22.4 18.7–26.8ROR 22.7 · χ² 2,410 / p <1e-300 | 22.1 EB05 19.0 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 31.1 · ♀ 98% (drug 71%) | no trial data cached |
| Bladder spasm | 17 | 22.2 13.8–35.7ROR 22.2 · χ² 320 / p 7e-72 | 21.5 EB05 14.0 · IC025 +3.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=6 | no trial data cached |
| Macular degeneration | 105 | 21.4 17.7–25.9ROR 21.6 · χ² 2,003 / p <1e-300 | 21.1 EB05 17.9 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 23.5 · ♀ 96% (drug 71%) | no trial data cached |
| Hypertonic bladder | 21 | 17.7 11.5–27.1ROR 17.7 · χ² 312 / p 5e-70 | 17.2 EB05 11.6 · IC025 +2.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=16 | no trial data cached |
| Paraesthesia oral | 96 | 16.2 13.2–19.7ROR 16.3 · χ² 1,343 / p 2e-294 | 16.0 EB05 13.5 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 28.6 · ♀ 100% (drug 71%) | no trial data cached |
| Infusion site discharge | 11 | 15.6 8.6–28.2ROR 15.6 · χ² 135 / p 2e-31 | 14.1 EB05 7.4 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious n=9 | no trial data cached |
| Eyelid pain | 12 | 15.0 8.5–26.4ROR 15.0 · χ² 142 / p 5e-33 | 13.6 EB05 7.4 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Clonus | 16 | 14.1 8.6–23.1ROR 14.1 · χ² 181 / p 1e-41 | 13.1 EB05 7.9 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Secondary progressive multiple sclerosis | 11 | 14.0 7.8–25.4ROR 14.1 · χ² 120 / p 4e-28 | 12.4 EB05 6.4 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Bladder disorder | 49 | 11.9 9.0–15.7ROR 12.0 · χ² 476 / p 7e-106 | 11.6 EB05 8.9 · IC025 +2.9 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=33 | no trial data cached |
| Frequent bowel movements | 127 | 11.4 9.6–13.6ROR 11.6 · χ² 1,191 / p 2e-261 | 11.2 EB05 9.7 · IC025 +3.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 17.0 · ♀ 97% (drug 71%) | no trial data cached |
| Escherichia urinary tract infection | 18 | 10.2 6.4–16.2ROR 10.3 · χ² 140 / p 1e-32 | 9.0 EB05 5.7 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious n=15 | no trial data cached |
| Peroneal nerve palsy | 22 | 9.3 6.2–14.2ROR 9.4 · χ² 155 / p 7e-36 | 8.4 EB05 5.6 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Infusion site pruritus | 12 | 9.3 5.3–16.4ROR 9.3 · χ² 80 / p 2e-19 | 7.6 EB05 4.4 · IC025 +1.8 3/3 methods agree | Labeled (related wording) related wording | serious n=11 | no trial data cached |
| Hallucinations, mixed | 16 | 9.2 5.6–15.0ROR 9.2 · χ² 108 / p 1e-25 | 7.9 EB05 4.9 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Decubitus ulcer | 30 | 8.9 6.2–12.7ROR 8.9 · χ² 202 / p 5e-46 | 8.2 EB05 5.9 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 9.5 | no trial data cached |
| Urine analysis abnormal | 11 | 8.8 4.9–15.9ROR 8.8 · χ² 68 / p 7e-17 | 7.0 EB05 4.0 · IC025 +1.7 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Micturition urgency | 41 | 8.7 6.4–11.9ROR 8.8 · χ² 272 / p 2e-61 | 8.2 EB05 6.2 · IC025 +2.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 9.0 | no trial data cached |
| Wheelchair user | 16 | 8.6 5.3–14.1ROR 8.7 · χ² 100 / p 6e-24 | 7.4 EB05 4.6 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Urinary incontinence | 106 | 8.6 7.1–10.4ROR 8.7 · χ² 707 / p 5e-156 | 8.4 EB05 7.1 · IC025 +2.7 3/3 methods agree | Likely indication confounding term in indications | serious PRR 8.1 | no trial data cached |
| Muscle spasticity | 44 | 8.6 6.4–11.5ROR 8.6 · χ² 286 / p 2e-64 | 8.1 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 10.5 | no trial data cached |
| Procedural pain | 97 | 8.5 6.9–10.3ROR 8.5 · χ² 630 / p 3e-139 | 8.2 EB05 6.9 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 14.6 · ♀ 100% (drug 71%) | no trial data cached |
| Walking aid user | 23 | 8.4 5.6–12.6ROR 8.4 · χ² 142 / p 5e-33 | 7.5 EB05 5.1 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious n=13 · 81% consumer | no trial data cached |
| Colitis | 128 | 8.2 6.9–9.7ROR 8.3 · χ² 801 / p 2e-176 | 8.0 EB05 6.9 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.0 · ♀ 96% (drug 71%) | no trial data cached |
| Nephrogenic anaemia | 15 | 7.7 4.7–12.8ROR 7.8 · χ² 81 / p 1e-19 | 6.5 EB05 4.1 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial data cached |
| Rectal haemorrhage | 135 | 7.6 6.4–8.9ROR 7.7 · χ² 760 / p 1e-167 | 7.4 EB05 6.4 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 8.3 · ♀ 94% (drug 71%) | no trial data cached |
| Multiple sclerosis | 146 | 7.3 6.2–8.6ROR 7.4 · χ² 791 / p 3e-174 | 7.2 EB05 6.2 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 · 72% consumer | no trial data cached |
| Incontinence | 32 | 7.3 5.2–10.3ROR 7.3 · χ² 167 / p 2e-38 | 6.7 EB05 4.9 · IC025 +2.1 3/3 methods agree | Likely indication confounding term in indications | serious PRR 6.0 · 70% consumer | no trial data cached |
| Trigeminal neuralgia | 12 | 7.2 4.1–12.7ROR 7.2 · χ² 58 / p 1e-14 | 5.8 EB05 3.5 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious n=6 | no trial data cached |
| Seasonal allergy | 42 | 7.2 5.3–9.7ROR 7.2 · χ² 217 / p 2e-49 | 6.7 EB05 5.1 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious n=16 · 80% consumer | no trial data cached |
| Decreased interest | 17 | 6.9 4.3–11.2ROR 7.0 · χ² 80 / p 1e-19 | 6.0 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious n=5 | 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 |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 729 | 2.3 2.1–2.4ROR 2.4 · χ² 530 / p 2e-117 | 2.3 EB05 2.1 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.4 | no trial data cached |
| Drug ineffective (drug did not work) | 695 | 1.3 1.2–1.4ROR 1.3 · χ² 42 / p 4e-11 | 1.3 EB05 1.2 · IC025 +0.2 | Reporting / coding artifact | serious PRR 1.7 | no trial data cached |
| Nausea | 602 | 1.8 1.7–2.0ROR 1.9 · χ² 237 / p 7e-54 | 1.8 EB05 1.7 · IC025 +0.7 | Labeled adverse reaction exact term | serious PRR 2.4 | no trial data cached |
| Fall | 579 | 4.2 3.9–4.5ROR 4.4 · χ² 1,427 / p <1e-300 | 4.2 EB05 3.9 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.0 | no trial data cached |
| Headache | 557 | 2.1 2.0–2.3ROR 2.2 · χ² 348 / p 6e-78 | 2.1 EB05 2.0 · IC025 +1.0 | Labeled adverse reaction exact term | serious PRR 2.8 | no trial data cached |
| Diarrhoea (diarrhea) | 507 | 1.9 1.7–2.1ROR 2.0 · χ² 221 / p 3e-50 | 1.9 EB05 1.8 · IC025 +0.8 | Labeled adverse reaction exact term | serious PRR 1.9 | no trial data cached |
| Pain | 481 | 1.9 1.7–2.1ROR 1.9 · χ² 204 / p 2e-46 | 1.9 EB05 1.7 · IC025 +0.8 | Labeled adverse reaction exact term | serious PRR 2.2 | no trial data cached |
| Urinary tract infection (bladder infection) | 446 | 6.3 5.8–6.9ROR 6.6 · χ² 2,005 / p <1e-300 | 6.3 EB05 5.8 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.5 | no trial data cached |
| Dizziness | 434 | 2.1 1.9–2.3ROR 2.2 · χ² 254 / p 1e-57 | 2.1 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 2.2 | no trial data cached |
| Constipation | 402 | 4.5 4.1–4.9ROR 4.6 · χ² 1,091 / p 1e-239 | 4.4 EB05 4.1 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.1 | no trial data cached |
| Asthenia (weakness) | 393 | 2.5 2.3–2.8ROR 2.6 · χ² 364 / p 2e-81 | 2.5 EB05 2.3 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.3 | no trial data cached |
| Off label use (used outside approved label) | 372 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.279 | 1.0 EB05 0.9 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.4 | no trial data cached |
| Weight decreased (weight loss) | 363 | 3.1 2.8–3.5ROR 3.2 · χ² 532 / p 7e-118 | 3.1 EB05 2.9 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Gait disturbance | 351 | 4.4 4.0–4.9ROR 4.5 · χ² 928 / p 4e-204 | 4.4 EB05 4.0 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 3.1 · 72% consumer | no trial data cached |
| Product dose omission issue | 339 | 2.9 2.6–3.2ROR 2.9 · χ² 416 / p 1e-92 | 2.9 EB05 2.6 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 4.8 · 74% consumer | 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.
- Vaginal flatulence — n=114, PRR 1,439.3
- Female genital tract fistula — n=116, PRR 173.9
- Radiculopathy — n=120, PRR 114.7
- Proctitis — n=116, PRR 103.8
- Chronic sinusitis — n=118, PRR 78.2
- Vaginal discharge — n=117, PRR 28.3
- Oral candidiasis — n=120, PRR 22.4
- Macular degeneration — n=105, PRR 21.4
- Paraesthesia oral — n=96, PRR 16.2
- Peroneal nerve palsy — n=22, PRR 9.3
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 Oxybutynin?
In FDA FAERS, the most frequently co-reported reaction terms for Oxybutynin are fatigue, nausea, fall, headache, diarrhoea, pain. 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 Oxybutynin have an FDA boxed warning?
No. The FDA label retrieved for Oxybutynin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Oxybutynin 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 1f95920c-5dc2-44e4-b61d-b2c5e05390ba, effective 20230206; matched on
openfda.generic_name.exact:"OXYBUTYNIN") - 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, 1,047 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.