Drug · FAERS side-effect profile with label screen

Balsalazide side effects: what 505 FDA adverse event reports show

Balsalazide Disodium · 12 reaction terms · 121 drug–reaction co-reports · data 2026-09-14

Drug class

Locally acting aminosalicylate

FDA label, Indications wording of the closest related product

Label matched

Balsalazide Disodium (Balsalazide Disodium)

closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match

Who reports

505 reports · 45% serious · 10 with death outcome · 55% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Balsalazide disodium capsules are indicated for the treatment of mildly to moderately active ulcerative colitis in patients 5 years of age and older. Limitations of Use Safety and effectiveness of balsalazide beyond 8 weeks in pediatric patients 5 years to 17 years of age and 12 weeks in adults have not been established.

FDA label, Indications and Usage

What it is

Each balsalazide disodium capsule, USP contains 750 mg of balsalazide disodium, a prodrug that is enzymatically cleaved in the colon to produce mesalamine (5-aminosalicylic acid or 5-ASA), an anti-inflammatory drug.

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 5 strongest signals

Labeled adverse reaction 1Labeled (related wording) 2Not in label — unassessed 2

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.
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. 7 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Diarrhoea haemorrhagic	7	31.1 14.9–64.8ROR 31.5 · χ² 175 / p 4e-40	28.5 EB05 14.2 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 36.4	no trial data cached
Colitis ulcerative	32	29.8 21.3–41.7ROR 31.8 · χ² 864 / p 4e-190	29.3 EB05 21.7 · IC025 +3.8 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 33.2 · 77% consumer	no trial data cached
Frequent bowel movements	12	18.5 10.6–32.4ROR 19.0 · χ² 182 / p 9e-42	17.6 EB05 10.0 · IC025 +2.5 3/3 methods agree	Not in label — unassessed	serious PRR 9.1	no trial data cached
Injection site pain (pain where injected)	39	5.3 3.9–7.2ROR 5.7 · χ² 135 / p 2e-31	5.0 EB05 3.8 · IC025 +1.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 6.7 · 89% consumer	no trial data cached
Injection site pruritus	8	5.0 2.5–9.9ROR 5.1 · χ² 22 / p 2e-6	4.0 EB05 2.2 · IC025 +0.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 5.6	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
Injection site pain (pain where injected)	39	5.3 3.9–7.2ROR 5.7 · χ² 135 / p 2e-31	5.0 EB05 3.8 · IC025 +1.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 6.7 · 89% consumer	no trial data cached
Colitis ulcerative	32	29.8 21.3–41.7ROR 31.8 · χ² 864 / p 4e-190	29.3 EB05 21.7 · IC025 +3.8 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 33.2 · 77% consumer	no trial data cached
Frequent bowel movements	12	18.5 10.6–32.4ROR 19.0 · χ² 182 / p 9e-42	17.6 EB05 10.0 · IC025 +2.5 3/3 methods agree	Not in label — unassessed	serious PRR 9.1	no trial data cached
Injection site pruritus	8	5.0 2.5–9.9ROR 5.1 · χ² 22 / p 2e-6	4.0 EB05 2.2 · IC025 +0.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 5.6	no trial data cached
Diarrhoea haemorrhagic	7	31.1 14.9–64.8ROR 31.5 · χ² 175 / p 4e-40	28.5 EB05 14.2 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 36.4	no trial data cached
Injection site haematoma	4	11.3 4.3–30.1ROR 11.4 · χ² 28 / p 6e-8	6.6 EB05 2.4 · IC025 +0.6 3/3 methods agree	Not in label — unassessed	serious n=1	no trial data cached
Inability to afford medication	4	16.9 6.4–44.9ROR 17.0 · χ² 45 / p 1e-11	11.0 EB05 3.3 · IC025 +0.8 3/3 methods agree	Not in label — unassessed	serious n=2	no trial data cached
Injection site rash	3	4.1 1.3–12.7ROR 4.1 · χ² 4 / p 0.019	2.8 EB05 1.1 · IC025 -0.6 PRR-only: not supported by EBGM or IC	Labeled (related wording) related wording	–	no trial data cached
Injection site irritation	3	9.8 3.2–30.4ROR 9.9 · χ² 16 / p 3e-5	5.0 EB05 1.8 · IC025 +0.1	Not in label — unassessed	–	no trial data cached
Myocarditis	3	11.0 3.6–34.0ROR 11.1 · χ² 18 / p 1e-5	5.6 EB05 1.9 · IC025 +0.1	Labeled adverse reaction exact term	serious PRR 9.4	no trial data cached
Injection site nodule	3	11.3 3.7–35.1ROR 11.4 · χ² 19 / p 7e-6	5.7 EB05 1.9 · IC025 +0.1	Not in label — unassessed	–	no trial data cached
Product odour abnormal	3	12.0 3.9–37.1ROR 12.1 · χ² 20 / p 3e-6	6.1 EB05 2.0 · IC025 +0.2	Reporting / coding artifact	–	no trial data cached

Unlabeled candidate signals

Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.

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 Balsalazide?

In FDA FAERS, the most frequently co-reported reaction terms for Balsalazide are injection site pain, colitis ulcerative, frequent bowel movements, injection site pruritus, diarrhoea haemorrhagic, injection site haematoma. 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 Balsalazide have an FDA boxed warning?

No. The FDA label retrieved for Balsalazide has no boxed warning; see the label's Warnings and Precautions for the recognised risks.

Do FAERS signals prove that Balsalazide 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 509b83b6-cde6-393b-8560-557793b6a529, effective 20251230; matched on openfda.generic_name.exact:"BALSALAZIDE DISODIUM")
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, field patient.drug.openfda.generic_name.exact, 12 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.