Drug · FAERS side-effect profile with label screen

Cysteamine side effects: what 659 FDA adverse event reports show

Cysteamine Hydrochloride · 12 reaction terms · 425 drug–reaction co-reports · data 2026-09-14

Drug class

Cystine-depleting agent

FDA label, Indications wording of the closest related product

Label matched

Cysteamine Hydrochloride (Cystaran)

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

Who reports

659 reports · 33% serious · 32 with death outcome · 57% female

openFDA FAERS counts, all years, deduplication not applied

Used for

CYSTARAN ® is a cystine-depleting agent indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis. CYSTARAN is a cystine-depleting agent indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis. ( 1 )

FDA label, Indications and Usage

What it is

CYSTARAN is a sterile ophthalmic solution containing 6.5 mg/mL of cysteamine hydrochloride, equivalent to 4.4 mg/mL of cysteamine (0.44%) as the active ingredient. Cysteamine is a cystine-depleting agent which lowers the cystine content of cells in patients with cystinosis.

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 7 strongest signals

Labeled adverse reaction 1Labeled (related wording) 1Reporting / coding artifact 1Not in label — unassessed 4

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.
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. 5 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
Eye irritation	178	101.9 89.9–115.6ROR 139.3 · χ² 17,676 / p <1e-300	100.5 EB05 88.7 · IC025 +6.1 3/3 methods agree	Labeled (related wording) related wording	serious PRR 70.0	no trial data cached
Photophobia (light sensitivity)	42	71.7 53.5–96.2ROR 76.5 · χ² 2,855 / p <1e-300	69.4 EB05 53.5 · IC025 +4.8 3/3 methods agree	Not in label — unassessed	serious PRR 24.3	no trial data cached
Eye pain	83	47.9 39.2–58.6ROR 54.6 · χ² 3,768 / p <1e-300	47.3 EB05 39.4 · IC025 +4.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 30.4	no trial data cached
Ocular hyperaemia	65	44.3 35.2–55.8ROR 49.1 · χ² 2,712 / p <1e-300	43.7 EB05 35.5 · IC025 +4.6 3/3 methods agree	Not in label — unassessed	serious PRR 24.6	no trial data cached
Conjunctivitis	15	26.0 15.8–42.9ROR 26.6 · χ² 336 / p 2e-75	25.2 EB05 16.1 · IC025 +3.0 3/3 methods agree	Not in label — unassessed	serious PRR 16.9	no trial data cached
Product use complaint	8	16.4 8.2–32.7ROR 16.6 · χ² 101 / p 5e-24	14.2 EB05 6.3 · IC025 +1.9 3/3 methods agree	Reporting / coding artifact	serious n=2	no trial data cached
Eye pruritus	16	15.4 9.5–25.1ROR 15.8 · χ² 202 / p 3e-46	14.7 EB05 9.0 · IC025 +2.6 3/3 methods agree	Not in label — unassessed	serious PRR 18.9	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
Eye irritation	178	101.9 89.9–115.6ROR 139.3 · χ² 17,676 / p <1e-300	100.5 EB05 88.7 · IC025 +6.1 3/3 methods agree	Labeled (related wording) related wording	serious PRR 70.0	no trial data cached
Eye pain	83	47.9 39.2–58.6ROR 54.6 · χ² 3,768 / p <1e-300	47.3 EB05 39.4 · IC025 +4.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 30.4	no trial data cached
Ocular hyperaemia	65	44.3 35.2–55.8ROR 49.1 · χ² 2,712 / p <1e-300	43.7 EB05 35.5 · IC025 +4.6 3/3 methods agree	Not in label — unassessed	serious PRR 24.6	no trial data cached
Photophobia (light sensitivity)	42	71.7 53.5–96.2ROR 76.5 · χ² 2,855 / p <1e-300	69.4 EB05 53.5 · IC025 +4.8 3/3 methods agree	Not in label — unassessed	serious PRR 24.3	no trial data cached
Eye pruritus	16	15.4 9.5–25.1ROR 15.8 · χ² 202 / p 3e-46	14.7 EB05 9.0 · IC025 +2.6 3/3 methods agree	Not in label — unassessed	serious PRR 18.9	no trial data cached
Conjunctivitis	15	26.0 15.8–42.9ROR 26.6 · χ² 336 / p 2e-75	25.2 EB05 16.1 · IC025 +3.0 3/3 methods agree	Not in label — unassessed	serious PRR 16.9	no trial data cached
Product use complaint	8	16.4 8.2–32.7ROR 16.6 · χ² 101 / p 5e-24	14.2 EB05 6.3 · IC025 +1.9 3/3 methods agree	Reporting / coding artifact	serious n=2	no trial data cached
Eye discharge	4	12.5 4.7–33.1ROR 12.5 · χ² 31 / p 1e-8	7.4 EB05 2.6 · IC025 +0.7 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Eye inflammation	4	13.5 5.1–35.9ROR 13.6 · χ² 35 / p 2e-9	8.1 EB05 2.7 · IC025 +0.7 3/3 methods agree	Not in label — unassessed	serious n=2	no trial data cached
Appendicitis	4	13.7 5.2–36.4ROR 13.8 · χ² 35 / p 1e-9	8.3 EB05 2.8 · IC025 +0.7 3/3 methods agree	Not in label — unassessed	serious PRR 18.3	no trial data cached
Device occlusion	3	6.9 2.2–21.2ROR 6.9 · χ² 10 / p 9e-4	3.9 EB05 1.5 · IC025 -0.2 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	serious n=3	no trial data cached
Nephropathy toxic	3	8.6 2.8–26.5ROR 8.6 · χ² 13 / p 1e-4	4.5 EB05 1.7 · IC025 -0.0 PRR-only: not supported by EBGM or IC	Not in label — unassessed	serious PRR 15.4	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.

Photophobia — n=42, PRR 71.7
Ocular hyperaemia — n=65, PRR 44.3

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 Cysteamine?

In FDA FAERS, the most frequently co-reported reaction terms for Cysteamine are eye irritation, eye pain, ocular hyperaemia, photophobia, eye pruritus, conjunctivitis. 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 Cysteamine have an FDA boxed warning?

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

Do FAERS signals prove that Cysteamine 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 b98ee838-ed23-42a9-93b5-72579e490fba, effective 20250430; matched on openfda.generic_name.exact:"CYSTEAMINE 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, 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.