Flutamide side effects: what 985 FDA adverse event reports show

Flutamide · Eulexin · 49 reaction terms · 622 drug–reaction co-reports · data 2026-09-14

Drug class

Androgen Receptor Inhibitor

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Eulexin

openFDA label

Who reports

985 reports · 90% serious · 250 with death outcome · 16% female

openFDA FAERS counts, all years, deduplication not applied

Used for

Eulexin ® capsules are indicated for use in combination with LHRH-agonists for the management of locally confined Stage B 2 -C and Stage D 2 metastatic carcinoma of the prostate. Stage B 2 -C Prostatic Carcinoma Treatment with Eulexin ® capsules and the goserelin acetate implant should start eight weeks prior to initiating radiation therapy and continue during radiation therapy.

FDA label, Indications and Usage

What it is

DESCRIPTION Eulexin ® capsules contain flutamide, an acetanilid, nonsteroidal, orally active antiandrogen having the chemical name, α,α,α-trifluoro-2-methyl-4'-nitro- m -propionotoluidide.

FDA label, Description section

Boxed warning

Hepatic Injury There have been postmarketing reports of hospitalization and rarely death due to liver failure in patients taking Eulexin ® . Evidence of hepatic injury included elevated serum transaminase levels, jaundice, hepatic encephalopathy and death related to acute hepatic failure.

FDA 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 17 strongest signals

Labeled adverse reaction 2Labeled (related wording) 1Likely indication confounding 1Reporting / coding artifact 1Lab value / disease marker 2Not in label — unassessed 10

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.
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. 32 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
Prostatic specific antigen increased	60	92.6 72.4–118.4ROR 98.5 · χ² 5,325 / p <1e-300	89.6 EB05 72.2 · IC025 +5.3 3/3 methods agree	Lab value / disease marker	serious PRR 90.8	no trial data cached
Metastases to bone	36	46.9 34.1–64.7ROR 48.7 · χ² 1,571 / p <1e-300	45.8 EB05 34.6 · IC025 +4.3 3/3 methods agree	Not in label — unassessed	serious PRR 30.4	no trial data cached
Nephropathy	12	27.3 15.5–47.8ROR 27.6 · χ² 278 / p 1e-62	26.1 EB05 15.8 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 18.6	no trial data cached
Osteonecrosis of jaw (jawbone death)	26	22.2 15.2–32.5ROR 22.8 · χ² 506 / p 2e-112	21.9 EB05 15.7 · IC025 +3.3 3/3 methods agree	Not in label — unassessed	serious PRR 14.3	no trial data cached
Prostate cancer	70	18.4 14.7–23.0ROR 19.7 · χ² 1,135 / p 3e-249	18.3 EB05 14.9 · IC025 +3.6 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious PRR 11.8	no trial data cached
Haematuria (blood in urine)	24	14.9 10.0–22.1ROR 15.3 · χ² 298 / p 5e-67	14.5 EB05 9.9 · IC025 +2.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 10.1	no trial data cached
Sleep apnoea syndrome	13	14.5 8.4–24.8ROR 14.7 · χ² 150 / p 9e-35	13.3 EB05 7.4 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 11.0	no trial data cached
Hepatic function abnormal	24	13.8 9.3–20.5ROR 14.1 · χ² 272 / p 2e-61	13.3 EB05 9.0 · IC025 +2.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 8.8	no trial data cached
Blood alkaline phosphatase increased	16	13.7 8.4–22.3ROR 13.9 · χ² 176 / p 2e-40	12.7 EB05 7.7 · IC025 +2.5 3/3 methods agree	Lab value / disease marker	serious PRR 10.1	no trial data cached
Urinary retention	21	13.4 8.8–20.5ROR 13.7 · χ² 230 / p 3e-52	12.8 EB05 8.4 · IC025 +2.6 3/3 methods agree	Not in label — unassessed	serious PRR 9.2	no trial data cached
Interstitial lung disease	30	13.2 9.3–18.8ROR 13.6 · χ² 327 / p 2e-73	12.8 EB05 9.1 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 8.5 · 93% clinician	no trial data cached
Bone disorder	11	12.7 7.1–23.0ROR 12.9 · χ² 108 / p 2e-25	11.0 EB05 5.8 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 10.0	no trial data cached
Intervertebral disc protrusion	12	11.7 6.6–20.5ROR 11.8 · χ² 107 / p 3e-25	10.0 EB05 5.5 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 8.8	no trial data cached
Taste disorder	10	10.6 5.7–19.7ROR 10.7 · χ² 78 / p 5e-19	8.5 EB05 4.5 · IC025 +1.8 3/3 methods agree	Not in label — unassessed	serious PRR 13.7	no trial data cached
Hepatitis (liver inflammation)	11	9.2 5.1–16.5ROR 9.2 · χ² 72 / p 1e-17	7.3 EB05 4.1 · IC025 +1.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.0	no trial data cached
Malignant neoplasm progression	34	7.1 5.1–9.9ROR 7.3 · χ² 173 / p 8e-40	6.6 EB05 4.9 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 4.5	no trial data cached
Osteonecrosis (bone death)	11	7.1 3.9–12.7ROR 7.1 · χ² 51 / p 4e-13	5.7 EB05 3.3 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 4.6	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
Prostate cancer	70	18.4 14.7–23.0ROR 19.7 · χ² 1,135 / p 3e-249	18.3 EB05 14.9 · IC025 +3.6 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious PRR 11.8	no trial data cached
Prostatic specific antigen increased	60	92.6 72.4–118.4ROR 98.5 · χ² 5,325 / p <1e-300	89.6 EB05 72.2 · IC025 +5.3 3/3 methods agree	Lab value / disease marker	serious PRR 90.8	no trial data cached
Metastases to bone	36	46.9 34.1–64.7ROR 48.7 · χ² 1,571 / p <1e-300	45.8 EB05 34.6 · IC025 +4.3 3/3 methods agree	Not in label — unassessed	serious PRR 30.4	no trial data cached
Malignant neoplasm progression	34	7.1 5.1–9.9ROR 7.3 · χ² 173 / p 8e-40	6.6 EB05 4.9 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 4.5	no trial data cached
Interstitial lung disease	30	13.2 9.3–18.8ROR 13.6 · χ² 327 / p 2e-73	12.8 EB05 9.1 · IC025 +2.9 3/3 methods agree	Not in label — unassessed	serious PRR 8.5 · 93% clinician	no trial data cached
Osteonecrosis of jaw (jawbone death)	26	22.2 15.2–32.5ROR 22.8 · χ² 506 / p 2e-112	21.9 EB05 15.7 · IC025 +3.3 3/3 methods agree	Not in label — unassessed	serious PRR 14.3	no trial data cached
Hepatic function abnormal	24	13.8 9.3–20.5ROR 14.1 · χ² 272 / p 2e-61	13.3 EB05 9.0 · IC025 +2.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 8.8	no trial data cached
Haematuria (blood in urine)	24	14.9 10.0–22.1ROR 15.3 · χ² 298 / p 5e-67	14.5 EB05 9.9 · IC025 +2.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 10.1	no trial data cached
Urinary retention	21	13.4 8.8–20.5ROR 13.7 · χ² 230 / p 3e-52	12.8 EB05 8.4 · IC025 +2.6 3/3 methods agree	Not in label — unassessed	serious PRR 9.2	no trial data cached
Blood alkaline phosphatase increased	16	13.7 8.4–22.3ROR 13.9 · χ² 176 / p 2e-40	12.7 EB05 7.7 · IC025 +2.5 3/3 methods agree	Lab value / disease marker	serious PRR 10.1	no trial data cached
Sleep apnoea syndrome	13	14.5 8.4–24.8ROR 14.7 · χ² 150 / p 9e-35	13.3 EB05 7.4 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 11.0	no trial data cached
Intervertebral disc protrusion	12	11.7 6.6–20.5ROR 11.8 · χ² 107 / p 3e-25	10.0 EB05 5.5 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 8.8	no trial data cached
Nephropathy	12	27.3 15.5–47.8ROR 27.6 · χ² 278 / p 1e-62	26.1 EB05 15.8 · IC025 +2.8 3/3 methods agree	Not in label — unassessed	serious PRR 18.6	no trial data cached
Osteonecrosis (bone death)	11	7.1 3.9–12.7ROR 7.1 · χ² 51 / p 4e-13	5.7 EB05 3.3 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 4.6	no trial data cached
Hepatitis (liver inflammation)	11	9.2 5.1–16.5ROR 9.2 · χ² 72 / p 1e-17	7.3 EB05 4.1 · IC025 +1.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.0	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.

Metastases to bone — n=36, PRR 46.9
Osteonecrosis of jaw — n=26, PRR 22.2
Urinary retention — n=21, PRR 13.4
Interstitial lung disease — n=30, PRR 13.2

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 Flutamide?

In FDA FAERS, the most frequently co-reported reaction terms for Flutamide are prostate cancer, prostatic specific antigen increased, metastases to bone, interstitial lung disease, osteonecrosis of jaw, hepatic function abnormal. 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 Flutamide have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: Hepatic Injury There have been postmarketing reports of hospitalization and rarely death due to liver failure in patients taking Eulexin ® . Evidence of hepatic injury included elevated serum transaminase levels, jaundice, hepatic encephalopathy and death related to acute hepatic failure.

Do FAERS signals prove that Flutamide 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 0a905e25-42b6-4937-a689-f01a8f22e644, effective 20250204; matched on openfda.generic_name.exact:"FLUTAMIDE")
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, 49 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.