Drug · FAERS side-effect profile with label screen
Ursodiol side effects: what 21,639 FDA adverse event reports show
Drug class
Bile Acid
FDA label (Established Pharmacologic Class)
Who reports
21,639 reports · 80% serious · 2,988 with death outcome · 56% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Ursodiol tablets are indicated for the treatment of patients with primary biliary cholangitis (PBC). Ursodiol tablets are bile acids indicated for the treatment of patients with primary biliary cholangitis. ( 1 )
FDA label, Indications and Usage
What it is
Ursodiol Tablets, USP 250 mg are available as a film-coated tablet for oral administration. Ursodiol Tablets, USP 500 mg are available as a scored film-coated tablet for oral administration. U.
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 (related wording) 1Likely indication confounding 7Reporting / coding artifact 1Lab value / disease marker 4Not in label — unassessed 27
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. 1,191 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 |
|---|---|---|---|---|---|---|
| Cftr gene mutation | 19 | 3,627.7 1,354.6–9,714.7ROR 3,630.9 · χ² 13,605 / p <1e-300 | 428.7 EB05 290.1 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial arm names this drug |
| Bile acids increased | 35 | 269.5 185.2–392.0ROR 269.9 · χ² 7,092 / p <1e-300 | 188.8 EB05 141.9 · IC025 +5.2 3/3 methods agree | Likely indication confounding term in indications | serious n=18 | no trial arm names this drug |
| Respiratory tract malformation | 28 | 264.7 174.2–402.2ROR 265.0 · χ² 5,553 / p <1e-300 | 181.9 EB05 132.1 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 100% (drug 56%) · 100% clinician | no trial arm names this drug |
| Philadelphia positive chronic myeloid leukaemia | 15 | 186.0 107.0–323.3ROR 186.1 · χ² 2,157 / p <1e-300 | 130.4 EB05 83.9 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial arm names this drug |
| Pulmonary malformation | 42 | 130.2 94.3–179.7ROR 130.4 · χ² 4,625 / p <1e-300 | 109.1 EB05 84.1 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=42 · ♀ 100% (drug 56%) · 90% clinician | no trial arm names this drug |
| Biliary cirrhosis | 22 | 117.3 75.4–182.7ROR 117.4 · χ² 2,157 / p <1e-300 | 96.1 EB05 66.9 · IC025 +4.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=22 | no trial arm names this drug |
| Blood alkaline phosphatase abnormal | 81 | 96.2 76.6–120.8ROR 96.5 · χ² 6,845 / p <1e-300 | 85.8 EB05 71.2 · IC025 +5.5 3/3 methods agree | Lab value / disease marker | serious n=65 · ♀ 92% (drug 56%) | no trial arm names this drug |
| Haemosiderosis | 24 | 94.7 62.3–144.0ROR 94.8 · χ² 1,939 / p <1e-300 | 80.9 EB05 57.2 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=24 · 100% clinician | no trial arm names this drug |
| Cholestasis of pregnancy | 35 | 80.3 56.9–113.4ROR 80.4 · χ² 2,456 / p <1e-300 | 71.4 EB05 53.7 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=34 · ♀ 100% (drug 56%) | no trial arm names this drug |
| Venoocclusive disease | 185 | 77.2 66.5–89.6ROR 77.8 · χ² 12,797 / p <1e-300 | 71.0 EB05 62.8 · IC025 +5.7 3/3 methods agree | Not in label — unassessed | serious n=184 · ♀ 29% (drug 56%) · 97% clinician | no trial arm names this drug |
| Primary biliary cholangitis | 34 | 76.9 54.2–109.1ROR 77.0 · χ² 2,288 / p <1e-300 | 68.6 EB05 51.4 · IC025 +4.6 3/3 methods agree | Likely indication confounding term in indications | serious n=32 · ♀ 100% (drug 56%) | no trial arm names this drug |
| Parenteral nutrition | 16 | 72.0 43.4–119.7ROR 72.1 · χ² 977 / p 8e-215 | 62.3 EB05 40.7 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial arm names this drug |
| Lung cyst | 27 | 71.4 48.3–105.5ROR 71.5 · χ² 1,679 / p <1e-300 | 63.6 EB05 45.9 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=27 · ♀ 100% (drug 56%) · 100% clinician | no trial arm names this drug |
| Biliary cirrhosis primary | 22 | 65.0 42.2–100.1ROR 65.1 · χ² 1,239 / p 1e-271 | 58.0 EB05 40.4 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=22 · ♀ 100% (drug 56%) | no trial arm names this drug |
| Venoocclusive liver disease | 286 | 59.8 53.1–67.3ROR 60.6 · χ² 15,502 / p <1e-300 | 56.1 EB05 50.9 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=286 · 97% clinician | no trial arm names this drug |
| Hepatic neoplasm malignant | 120 | 57.5 47.8–69.0ROR 57.8 · χ² 6,226 / p <1e-300 | 53.8 EB05 46.2 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=120 · ♀ 22% (drug 56%) · 100% clinician | no trial arm names this drug |
| Device related bacteraemia | 15 | 50.8 30.2–85.3ROR 50.8 · χ² 649 / p 2e-143 | 45.7 EB05 29.4 · IC025 +3.4 3/3 methods agree | Reporting / coding artifact | serious n=15 | no trial arm names this drug |
| Cystic fibrosis respiratory infection suppression | 42 | 47.4 34.8–64.6ROR 47.5 · χ² 1,773 / p <1e-300 | 44.4 EB05 34.2 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=42 · 79% consumer | no trial arm names this drug |
| Cholangitis sclerosing | 95 | 46.7 38.0–57.4ROR 46.9 · χ² 4,009 / p <1e-300 | 44.2 EB05 37.2 · IC025 +4.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=94 | no trial arm names this drug |
| Lactation disorder | 22 | 45.7 29.8–70.0ROR 45.7 · χ² 875 / p 1e-192 | 42.1 EB05 29.3 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=22 | no trial arm names this drug |
| Vanishing bile duct syndrome | 50 | 45.6 34.4–60.6ROR 45.7 · χ² 2,041 / p <1e-300 | 42.9 EB05 33.8 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=50 · ♀ 35% (drug 56%) · 100% clinician | no trial arm names this drug |
| Aplastic anaemia | 229 | 44.2 38.7–50.4ROR 44.7 · χ² 9,202 / p <1e-300 | 42.2 EB05 37.8 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=229 · 100% clinician | no trial arm names this drug |
| Infective pulmonary exacerbation of cystic fibrosis | 237 | 43.7 38.4–49.8ROR 44.2 · χ² 9,420 / p <1e-300 | 41.7 EB05 37.4 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=214 | no trial arm names this drug |
| Portal hypertensive gastropathy | 24 | 43.6 29.0–65.7ROR 43.7 · χ² 916 / p 2e-201 | 40.5 EB05 28.7 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=24 | no trial arm names this drug |
| Poor sucking reflex | 17 | 42.7 26.3–69.4ROR 42.7 · χ² 623 / p 7e-138 | 39.3 EB05 26.0 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial arm names this drug |
| Gamma-glutamyltransferase abnormal | 25 | 42.5 28.5–63.4ROR 42.5 · χ² 930 / p 2e-204 | 39.6 EB05 28.2 · IC025 +3.8 3/3 methods agree | Lab value / disease marker | serious n=24 · ♀ 100% (drug 56%) | no trial arm names this drug |
| Biliary tract infection | 24 | 39.6 26.3–59.5ROR 39.6 · χ² 830 / p 9e-183 | 37.0 EB05 26.2 · IC025 +3.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=23 | no trial arm names this drug |
| Complications of transplanted liver | 14 | 38.6 22.6–65.9ROR 38.7 · χ² 458 / p 8e-102 | 35.5 EB05 22.5 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial arm names this drug |
| Disseminated aspergillosis | 18 | 38.6 24.1–61.8ROR 38.6 · χ² 598 / p 2e-132 | 35.9 EB05 24.0 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=18 | no trial arm names this drug |
| Red blood cell transfusion | 14 | 35.1 20.6–59.8ROR 35.1 · χ² 415 / p 2e-92 | 32.5 EB05 20.6 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial arm names this drug |
| Bile duct stenosis | 41 | 34.2 25.0–46.6ROR 34.2 · χ² 1,242 / p 2e-272 | 32.6 EB05 25.0 · IC025 +4.1 3/3 methods agree | Labeled (related wording) related wording | serious n=41 | no trial arm names this drug |
| Cholangitis acute | 24 | 32.7 21.8–49.2ROR 32.8 · χ² 683 / p 6e-151 | 31.0 EB05 21.9 · IC025 +3.6 3/3 methods agree | Likely indication confounding term in indications | serious n=24 · 100% clinician | no trial arm names this drug |
| Aspartate aminotransferase abnormal | 47 | 31.1 23.2–41.5ROR 31.1 · χ² 1,296 / p 4e-284 | 29.8 EB05 23.3 · IC025 +4.0 3/3 methods agree | Lab value / disease marker | serious n=45 · ♀ 86% (drug 56%) | no trial arm names this drug |
| Engraftment syndrome | 17 | 28.8 17.8–46.7ROR 28.8 · χ² 417 / p 7e-93 | 27.2 EB05 18.0 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial arm names this drug |
| Acute graft versus host disease | 131 | 28.2 23.8–33.6ROR 28.4 · χ² 3,319 / p <1e-300 | 27.4 EB05 23.7 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=130 · ♀ 35% (drug 56%) · 94% clinician | no trial arm names this drug |
| Lymphocyte stimulation test positive | 23 | 28.2 18.6–42.7ROR 28.3 · χ² 560 / p 3e-124 | 26.9 EB05 18.9 · IC025 +3.4 3/3 methods agree | Lab value / disease marker | serious n=23 | no trial arm names this drug |
| Enterococcal sepsis | 23 | 28.0 18.5–42.4ROR 28.1 · χ² 557 / p 2e-123 | 26.7 EB05 18.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=23 · 100% clinician | no trial arm names this drug |
| Acute graft versus host disease in skin | 77 | 27.8 22.1–34.8ROR 27.9 · χ² 1,905 / p <1e-300 | 26.9 EB05 22.2 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=77 · ♀ 32% (drug 56%) · 100% clinician | no trial arm names this drug |
| Hepatorenal syndrome | 46 | 27.0 20.1–36.1ROR 27.0 · χ² 1,094 / p 4e-240 | 26.0 EB05 20.3 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=44 · ♀ 29% (drug 56%) | no trial arm names this drug |
| Portal hypertension | 82 | 26.4 21.2–32.9ROR 26.5 · χ² 1,926 / p <1e-300 | 25.6 EB05 21.3 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=80 | no trial arm names this drug |
Trial evidence (ClinicalTrials.gov)
ClinicalTrials.gov returned results-bearing trials mentioning Ursodiol only as a background or rescue medication (NCT00200343, NCT03602560); no trial listing it as the tested intervention was cached, so no trial cross-check is shown.
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 |
|---|---|---|---|---|---|---|
| Off label use (used outside approved label) | 1,763 | 2.0 1.9–2.1ROR 2.1 · χ² 875 / p 2e-192 | 2.0 EB05 1.9 · IC025 +0.9 | Reporting / coding artifact | serious PRR 2.2 | no trial arm names this drug |
| Pruritus (itching) | 1,299 | 3.3 3.2–3.5ROR 3.5 · χ² 2,155 / p <1e-300 | 3.3 EB05 3.2 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.6 · ♀ 78% (drug 56%) | no trial arm names this drug |
| Diarrhoea (diarrhea) | 1,222 | 1.8 1.7–1.9ROR 1.9 · χ² 483 / p 2e-107 | 1.8 EB05 1.8 · IC025 +0.8 | Labeled adverse reaction exact term | serious PRR 1.8 | no trial arm names this drug |
| Fatigue (tiredness) | 1,093 | 1.4 1.3–1.4ROR 1.4 · χ² 109 / p 7e-26 | 1.4 EB05 1.3 · IC025 +0.3 | Labeled (related wording) related wording | serious PRR 1.2 | no trial arm names this drug |
| Nausea | 1,061 | 1.3 1.2–1.4ROR 1.3 · χ² 77 / p 8e-19 | 1.3 EB05 1.2 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.3 | no trial arm names this drug |
| Pyrexia (fever) | 990 | 2.8 2.6–2.9ROR 2.9 · χ² 1,137 / p 1e-249 | 2.8 EB05 2.6 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.4 | no trial arm names this drug |
| Drug ineffective (drug did not work) | 950 | 0.7 0.7–0.7ROR 0.7 · χ² 131 / p 1e-30 | 0.7 EB05 0.7 · IC025 -0.6 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.1 | no trial arm names this drug |
| Pneumonia (lung infection) | 779 | 2.3 2.2–2.5ROR 2.4 · χ² 602 / p 2e-133 | 2.3 EB05 2.2 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 1.7 | no trial arm names this drug |
| Death | 716 | 0.8 0.7–0.9ROR 0.8 · χ² 35 / p 2e-9 | 0.8 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction | serious PRR 0.6 | no trial arm names this drug |
| Vomiting | 687 | 1.4 1.3–1.5ROR 1.4 · χ² 87 / p 7e-21 | 1.4 EB05 1.3 · IC025 +0.4 | Labeled adverse reaction exact term | serious PRR 1.3 | no trial arm names this drug |
| Headache | 630 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.261 | 1.0 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 1.0 | no trial arm names this drug |
| Dyspnoea (shortness of breath) | 596 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.315 | 1.0 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 0.9 | no trial arm names this drug |
| Rash | 563 | 1.3 1.2–1.4ROR 1.3 · χ² 30 / p 2e-8 | 1.3 EB05 1.2 · IC025 +0.2 | Labeled adverse reaction exact term | serious PRR 1.4 | no trial arm names this drug |
| Abdominal pain | 548 | 2.3 2.1–2.5ROR 2.3 · χ² 399 / p 6e-89 | 2.3 EB05 2.1 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 1.9 | no trial arm names this drug |
| Decreased appetite (loss of appetite) | 547 | 2.3 2.1–2.5ROR 2.3 · χ² 400 / p 3e-89 | 2.3 EB05 2.1 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 | no trial arm names this drug |
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.
- Respiratory tract malformation — n=28, PRR 264.7
- Pulmonary malformation — n=42, PRR 130.2
- Haemosiderosis — n=24, PRR 94.7
- Cholestasis of pregnancy — n=35, PRR 80.3
- Venoocclusive disease — n=185, PRR 77.2
- Lung cyst — n=27, PRR 71.4
- Venoocclusive liver disease — n=286, PRR 59.8
- Hepatic neoplasm malignant — n=120, PRR 57.5
- Cystic fibrosis respiratory infection suppression — n=42, PRR 47.4
- Lactation disorder — n=22, PRR 45.7
✓ A hand-written Bradford Hill causality assessment exists for this drug: Ursodiol ↔ Pruritus.
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 Ursodiol?
In FDA FAERS, the most frequently co-reported reaction terms for Ursodiol are pruritus, diarrhoea, fatigue, nausea, pyrexia, pneumonia. 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 Ursodiol have an FDA boxed warning?
No. The FDA label retrieved for Ursodiol has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Ursodiol 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 1a3a8942-94d4-4292-bf74-0a67d92acb90, effective 20260612; matched on
openfda.generic_name.exact:"URSODIOL") - 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, 1,231 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 - ClinicalTrials.gov API v2 (query
URSODIOL, results-bearing studies sorted by enrollment)
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.