Darifenacin side effects: what 600 FDA adverse event reports show
Drug class
Not stated in label
Who reports
600 reports · 77% serious · 57 with death outcome · 75% female
Used for
Darifenacin extended-release tablets are indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency and frequency. Darifenacin extended-release tablets are a muscarinic antagonist indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency and frequency ( 1 )
What it is
Darifenacin is an extended-release tablet for oral administration which contains 7.5 mg or 15 mg darifenacin as its hydrobromide salt. The active moiety, darifenacin, is a potent muscarinic receptor antagonist.
Boxed warning
None in the current label
Causality screen of the 19 strongest signals
What the badges mean
- 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. 1 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 |
|---|---|---|---|---|---|---|
| Synovitis | 54 | 104.9 81.3–135.3ROR 115.1 · χ² 5,440 / p <1e-300 | 100.9 EB05 80.3 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious PRR 82.1 · ♀ 98% (drug 75%) | no trial data cached |
| Tenderness | 27 | 90.6 62.6–131.0ROR 94.8 · χ² 2,299 / p <1e-300 | 85.1 EB05 61.4 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=27 | no trial data cached |
| Oral pain | 57 | 88.9 69.4–113.8ROR 98.1 · χ² 4,858 / p <1e-300 | 86.2 EB05 69.0 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious PRR 121.9 · ♀ 98% (drug 75%) | no trial data cached |
| Fibromyalgia | 52 | 75.0 57.8–97.3ROR 82.0 · χ² 3,718 / p <1e-300 | 72.9 EB05 57.7 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious PRR 73.8 · ♀ 98% (drug 75%) | no trial data cached |
| Liver function test abnormal | 54 | 64.6 50.1–83.3ROR 70.9 · χ² 3,316 / p <1e-300 | 63.1 EB05 50.2 · IC025 +4.9 3/3 methods agree | Reporting / coding artifact | serious PRR 60.2 · ♀ 96% (drug 75%) | no trial data cached |
| Herpes zoster (shingles) | 83 | 50.5 41.3–61.6ROR 58.4 · χ² 3,980 / p <1e-300 | 49.9 EB05 41.5 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious PRR 60.1 · ♀ 99% (drug 75%) | no trial data cached |
| Blood cholesterol increased | 55 | 41.3 32.1–53.1ROR 45.3 · χ² 2,123 / p <1e-300 | 40.7 EB05 32.4 · IC025 +4.5 3/3 methods agree | Lab value / disease marker | serious PRR 46.8 | no trial data cached |
| Leukopenia (low white blood cells) | 53 | 37.2 28.7–48.1ROR 40.7 · χ² 1,832 / p <1e-300 | 36.7 EB05 29.1 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 28.9 · ♀ 96% (drug 75%) | no trial data cached |
| Arthritis | 56 | 24.9 19.4–31.9ROR 27.3 · χ² 1,262 / p 9e-277 | 24.7 EB05 19.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 28.4 · ♀ 98% (drug 75%) | no trial data cached |
| Contraindicated product administered | 21 | 24.3 16.0–37.1ROR 25.2 · χ² 447 / p 1e-99 | 23.9 EB05 16.4 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 22.7 | no trial data cached |
| Inappropriate antidiuretic hormone secretion | 7 | 24.0 11.5–50.2ROR 24.3 · χ² 132 / p 6e-31 | 21.8 EB05 9.9 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 18.2 | no trial data cached |
| Muscle spasticity | 8 | 22.6 11.3–44.9ROR 22.8 · χ² 144 / p 2e-33 | 20.8 EB05 10.1 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 18.1 | no trial data cached |
| Arteriosclerosis | 6 | 22.3 10.0–49.4ROR 22.5 · χ² 101 / p 4e-24 | 19.3 EB05 7.3 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 17.2 | no trial data cached |
| Bladder disorder | 6 | 21.1 9.5–46.8ROR 21.3 · χ² 96 / p 7e-23 | 18.0 EB05 6.7 · IC025 +1.6 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=2 | no trial data cached |
| Peripheral swelling | 91 | 20.7 17.2–25.1ROR 24.3 · χ² 1,701 / p <1e-300 | 20.6 EB05 17.3 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 26.6 | no trial data cached |
| Tachypnoea | 8 | 20.6 10.4–41.1ROR 20.9 · χ² 131 / p 2e-30 | 18.8 EB05 8.8 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 15.9 | no trial data cached |
| Cyanosis (blue skin from low oxygen) | 7 | 15.5 7.4–32.4ROR 15.7 · χ² 81 / p 1e-19 | 12.7 EB05 5.2 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 12.3 | no trial data cached |
| Joint swelling | 49 | 14.2 10.9–18.6ROR 15.4 · χ² 592 / p 4e-131 | 14.0 EB05 10.9 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 18.0 · ♀ 96% (drug 75%) | no trial data cached |
| Prescribed overdose | 7 | 12.6 6.1–26.4ROR 12.8 · χ² 64 / p 7e-16 | 9.6 EB05 4.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 16.2 | 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 |
|---|---|---|---|---|---|---|
| Peripheral swelling | 91 | 20.7 17.2–25.1ROR 24.3 · χ² 1,701 / p <1e-300 | 20.6 EB05 17.3 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 26.6 | no trial data cached |
| Herpes zoster (shingles) | 83 | 50.5 41.3–61.6ROR 58.4 · χ² 3,980 / p <1e-300 | 49.9 EB05 41.5 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious PRR 60.1 · ♀ 99% (drug 75%) | no trial data cached |
| Oral pain | 57 | 88.9 69.4–113.8ROR 98.1 · χ² 4,858 / p <1e-300 | 86.2 EB05 69.0 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious PRR 121.9 · ♀ 98% (drug 75%) | no trial data cached |
| Arthritis | 56 | 24.9 19.4–31.9ROR 27.3 · χ² 1,262 / p 9e-277 | 24.7 EB05 19.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 28.4 · ♀ 98% (drug 75%) | no trial data cached |
| Blood cholesterol increased | 55 | 41.3 32.1–53.1ROR 45.3 · χ² 2,123 / p <1e-300 | 40.7 EB05 32.4 · IC025 +4.5 3/3 methods agree | Lab value / disease marker | serious PRR 46.8 | no trial data cached |
| Liver function test abnormal | 54 | 64.6 50.1–83.3ROR 70.9 · χ² 3,316 / p <1e-300 | 63.1 EB05 50.2 · IC025 +4.9 3/3 methods agree | Reporting / coding artifact | serious PRR 60.2 · ♀ 96% (drug 75%) | no trial data cached |
| Synovitis | 54 | 104.9 81.3–135.3ROR 115.1 · χ² 5,440 / p <1e-300 | 100.9 EB05 80.3 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious PRR 82.1 · ♀ 98% (drug 75%) | no trial data cached |
| Leukopenia (low white blood cells) | 53 | 37.2 28.7–48.1ROR 40.7 · χ² 1,832 / p <1e-300 | 36.7 EB05 29.1 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 28.9 · ♀ 96% (drug 75%) | no trial data cached |
| Fibromyalgia | 52 | 75.0 57.8–97.3ROR 82.0 · χ² 3,718 / p <1e-300 | 72.9 EB05 57.7 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious PRR 73.8 · ♀ 98% (drug 75%) | no trial data cached |
| Joint swelling | 49 | 14.2 10.9–18.6ROR 15.4 · χ² 592 / p 4e-131 | 14.0 EB05 10.9 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 18.0 · ♀ 96% (drug 75%) | no trial data cached |
| Tenderness | 27 | 90.6 62.6–131.0ROR 94.8 · χ² 2,299 / p <1e-300 | 85.1 EB05 61.4 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=27 | no trial data cached |
| Contraindicated product administered | 21 | 24.3 16.0–37.1ROR 25.2 · χ² 447 / p 1e-99 | 23.9 EB05 16.4 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 22.7 | no trial data cached |
| Tachypnoea | 8 | 20.6 10.4–41.1ROR 20.9 · χ² 131 / p 2e-30 | 18.8 EB05 8.8 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 15.9 | no trial data cached |
| Muscle spasticity | 8 | 22.6 11.3–44.9ROR 22.8 · χ² 144 / p 2e-33 | 20.8 EB05 10.1 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 18.1 | no trial data cached |
| Prescribed overdose | 7 | 12.6 6.1–26.4ROR 12.8 · χ² 64 / p 7e-16 | 9.6 EB05 4.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 16.2 | 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.
- Synovitis — n=54, PRR 104.9
- Tenderness — n=27, PRR 90.6
- Oral pain — n=57, PRR 88.9
- Fibromyalgia — n=52, PRR 75.0
- Herpes zoster — n=83, PRR 50.5
- Leukopenia — n=53, PRR 37.2
- Arthritis — n=56, PRR 24.9
- Joint swelling — n=49, PRR 14.2
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 Darifenacin?
In FDA FAERS, the most frequently co-reported reaction terms for Darifenacin are peripheral swelling, herpes zoster, oral pain, arthritis, blood cholesterol increased, synovitis. 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 Darifenacin have an FDA boxed warning?
No. The FDA label retrieved for Darifenacin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Darifenacin 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 28ed5b58-46dd-4140-a877-4b422f780a94, effective 20240419; matched on
openfda.generic_name.exact:"DARIFENACIN") - 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, 20 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.