Bismuth Subcitrate side effects: what 1,115 FDA adverse event reports show
Drug class
Nitroimidazole Antimicrobial
Label matched
Bismuth Subcitrate Potassium, Metronidazole, And Tetracycline Hydrochloride (Pylera)
Who reports
1,115 reports · 83% serious · 18 with death outcome · 63% female
Used for
PYLERA is a combination of metronidazole, a nitroimidazole antimicrobial, tetracycline,- a tetracycline class antimicrobial and bismuth subcitrate potassium, indicated for use, in combination with omeprazole, for the treatment of patients with Helicobacter pylori infection and duodenal ulcer disease (active or history of within the past 5 years) to eradicate H. pylori.
What it is
PYLERA capsules are a combination antimicrobial product containing bismuth subcitrate potassium, metronidazole, and tetracycline hydrochloride for oral administration. Each size 0 elongated ca.
Boxed warning
POTENTIAL FOR CARCINOGENICITY Metronidazole has been shown to be carcinogenic in mice and rats. It is unknown whether metronidazole is associated with carcinogenicity in humans [see Warning and Precautions ( 5.1 )] . WARNING: POTENTIAL FOR CARCINOGENICITY See full prescribing information for complete boxed warning.
Causality screen of the 19 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.
- 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. 17 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 |
|---|---|---|---|---|---|---|
| Faeces discoloured | 80 | 69.7 56.4–86.1ROR 75.0 · χ² 5,331 / p <1e-300 | 68.3 EB05 56.6 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious PRR 49.4 | no trial data cached |
| Toxic skin eruption | 19 | 35.4 22.7–55.3ROR 36.0 · χ² 601 / p 6e-133 | 34.3 EB05 23.2 · IC025 +3.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 24.7 | no trial data cached |
| Chromaturia | 37 | 30.9 22.5–42.4ROR 31.9 · χ² 1,038 / p 4e-228 | 30.4 EB05 23.0 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 27.4 · ♀ 84% (drug 63%) | no trial data cached |
| Helicobacter infection | 16 | 29.6 18.2–48.1ROR 30.0 · χ² 413 / p 4e-92 | 28.6 EB05 18.6 · IC025 +3.1 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 19.0 | no trial data cached |
| Clostridium difficile colitis | 13 | 23.0 13.4–39.6ROR 23.3 · χ² 252 / p 4e-57 | 22.2 EB05 13.6 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 16.3 | no trial data cached |
| Hepatocellular injury | 16 | 21.2 13.0–34.5ROR 21.5 · χ² 288 / p 8e-65 | 20.6 EB05 13.2 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 14.7 | no trial data cached |
| Face oedema | 18 | 20.0 12.6–31.6ROR 20.3 · χ² 306 / p 8e-69 | 19.5 EB05 12.9 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 15.5 | no trial data cached |
| Pharyngeal oedema | 11 | 13.3 7.4–23.9ROR 13.4 · χ² 113 / p 1e-26 | 11.6 EB05 6.0 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 12.2 | no trial data cached |
| Vertigo (spinning dizziness) | 43 | 13.3 9.9–17.8ROR 13.8 · χ² 477 / p 6e-106 | 13.0 EB05 9.9 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.8 | no trial data cached |
| Angioedema (deep swelling of face/throat) | 31 | 13.2 9.3–18.7ROR 13.6 · χ² 338 / p 7e-76 | 12.8 EB05 9.2 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.7 | no trial data cached |
| Melaena (black stool) | 14 | 11.9 7.1–20.1ROR 12.1 · χ² 130 / p 2e-30 | 10.6 EB05 6.1 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.5 | no trial data cached |
| Pancreatitis acute | 13 | 11.0 6.4–18.8ROR 11.1 · χ² 108 / p 1e-25 | 9.4 EB05 5.3 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.6 | no trial data cached |
| Cholestasis (bile flow blockage) | 11 | 10.8 6.0–19.5ROR 10.9 · χ² 89 / p 2e-21 | 8.9 EB05 4.8 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Tinnitus (ringing in the ears) | 24 | 9.8 6.6–14.6ROR 10.0 · χ² 182 / p 1e-41 | 8.9 EB05 6.1 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.1 | no trial data cached |
| Clostridium difficile infection | 11 | 9.5 5.3–17.2ROR 9.6 · χ² 76 / p 1e-18 | 7.7 EB05 4.3 · IC025 +1.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.0 | no trial data cached |
| Diplopia (double vision) | 13 | 9.4 5.5–16.2ROR 9.5 · χ² 90 / p 1e-21 | 7.8 EB05 4.6 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.0 | no trial data cached |
| Dysgeusia (altered taste) | 37 | 9.3 6.8–12.8ROR 9.6 · χ² 267 / p 2e-60 | 8.8 EB05 6.5 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 16.2 · ♀ 86% (drug 63%) | no trial data cached |
| Visual acuity reduced | 11 | 6.2 3.4–11.1ROR 6.2 · χ² 43 / p 3e-11 | 5.0 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 | no trial data cached |
| Inappropriate schedule of drug administration | 12 | 3.1 1.8–5.5ROR 3.2 · χ² 15 / p 4e-5 | 2.9 EB05 1.8 · IC025 +0.5 | Reporting / coding artifact | serious PRR 5.1 | 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 |
|---|---|---|---|---|---|---|
| Faeces discoloured | 80 | 69.7 56.4–86.1ROR 75.0 · χ² 5,331 / p <1e-300 | 68.3 EB05 56.6 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious PRR 49.4 | no trial data cached |
| Vertigo (spinning dizziness) | 43 | 13.3 9.9–17.8ROR 13.8 · χ² 477 / p 6e-106 | 13.0 EB05 9.9 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.8 | no trial data cached |
| Dysgeusia (altered taste) | 37 | 9.3 6.8–12.8ROR 9.6 · χ² 267 / p 2e-60 | 8.8 EB05 6.5 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 16.2 · ♀ 86% (drug 63%) | no trial data cached |
| Chromaturia | 37 | 30.9 22.5–42.4ROR 31.9 · χ² 1,038 / p 4e-228 | 30.4 EB05 23.0 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 27.4 · ♀ 84% (drug 63%) | no trial data cached |
| Angioedema (deep swelling of face/throat) | 31 | 13.2 9.3–18.7ROR 13.6 · χ² 338 / p 7e-76 | 12.8 EB05 9.2 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.7 | no trial data cached |
| Tinnitus (ringing in the ears) | 24 | 9.8 6.6–14.6ROR 10.0 · χ² 182 / p 1e-41 | 8.9 EB05 6.1 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.1 | no trial data cached |
| Toxic skin eruption | 19 | 35.4 22.7–55.3ROR 36.0 · χ² 601 / p 6e-133 | 34.3 EB05 23.2 · IC025 +3.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 24.7 | no trial data cached |
| Face oedema | 18 | 20.0 12.6–31.6ROR 20.3 · χ² 306 / p 8e-69 | 19.5 EB05 12.9 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 15.5 | no trial data cached |
| Hepatocellular injury | 16 | 21.2 13.0–34.5ROR 21.5 · χ² 288 / p 8e-65 | 20.6 EB05 13.2 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 14.7 | no trial data cached |
| Helicobacter infection | 16 | 29.6 18.2–48.1ROR 30.0 · χ² 413 / p 4e-92 | 28.6 EB05 18.6 · IC025 +3.1 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 19.0 | no trial data cached |
| Melaena (black stool) | 14 | 11.9 7.1–20.1ROR 12.1 · χ² 130 / p 2e-30 | 10.6 EB05 6.1 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 8.5 | no trial data cached |
| Diplopia (double vision) | 13 | 9.4 5.5–16.2ROR 9.5 · χ² 90 / p 1e-21 | 7.8 EB05 4.6 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.0 | no trial data cached |
| Pancreatitis acute | 13 | 11.0 6.4–18.8ROR 11.1 · χ² 108 / p 1e-25 | 9.4 EB05 5.3 · IC025 +2.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.6 | no trial data cached |
| Clostridium difficile colitis | 13 | 23.0 13.4–39.6ROR 23.3 · χ² 252 / p 4e-57 | 22.2 EB05 13.6 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 16.3 | no trial data cached |
| Inappropriate schedule of drug administration | 12 | 3.1 1.8–5.5ROR 3.2 · χ² 15 / p 4e-5 | 2.9 EB05 1.8 · IC025 +0.5 | Reporting / coding artifact | serious PRR 5.1 | 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.
- Faeces discoloured — n=80, PRR 69.7
- Chromaturia — n=37, PRR 30.9
✓ A hand-written Bradford Hill causality assessment exists for this drug: Metronidazole ↔ Peripheral neuropathy.
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 Bismuth Subcitrate?
In FDA FAERS, the most frequently co-reported reaction terms for Bismuth Subcitrate are faeces discoloured, vertigo, dysgeusia, chromaturia, angioedema, tinnitus. 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 Bismuth Subcitrate have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: POTENTIAL FOR CARCINOGENICITY Metronidazole has been shown to be carcinogenic in mice and rats. It is unknown whether metronidazole is associated with carcinogenicity in humans [see Warning and Precautions ( 5.1 )] . WARNING: POTENTIAL FOR CARCINOGENICITY See full prescribing information for complete boxed warning.
Do FAERS signals prove that Bismuth Subcitrate 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 c50626a2-5969-490b-a88a-a4ee45e79615, effective 20260116; matched on
openfda.generic_name.exact:"BISMUTH SUBCITRATE POTASSIUM, METRONIDAZOLE, AND TETRACYCLINE HYDROCHLORIDE") - 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, 36 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.