Drug · FAERS side-effect profile with label screen

Monomethyl side effects: what 926 FDA adverse event reports show

Monomethyl Fumarate · 9 reaction terms · 542 drug–reaction co-reports · data 2026-09-14

Drug class

Not stated in label

Label matched

Monomethyl Fumarate (Bafiertam)

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

Who reports

926 reports · 13% serious · 3 with death outcome · 85% female

openFDA FAERS counts, all years, deduplication not applied

Used for

BAFIERTAM is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. BAFIERTAM is indicated for the treatment .

FDA label, Indications and Usage

What it is

BAFIERTAM contains the active ingredient monomethyl fumarate, which is an unsaturated monomethyl ester. It is also known by its chemical name, fumaric acid monomethyl ester, (C 5 H 6 O 4 ). It.

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 9 strongest signals

Labeled adverse reaction 2Labeled (related wording) 2Likely indication confounding 2Not in label — unassessed 3

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.
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. 0 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
Flushing	348	77.4 71.2–84.2ROR 123.4 · χ² 26,215 / p <1e-300	76.9 EB05 70.3 · IC025 +5.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 47.2 · 92% consumer	no trial data cached
Insurance issue	11	16.8 9.3–30.2ROR 17.0 · χ² 148 / p 3e-34	15.5 EB05 8.2 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 14.0	no trial data cached
Feeling hot	41	15.1 11.2–20.4ROR 15.8 · χ² 528 / p 3e-117	14.9 EB05 11.4 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 3.5 · 95% consumer	no trial data cached
Muscle spasticity	8	14.6 7.3–29.1ROR 14.7 · χ² 88 / p 3e-21	12.2 EB05 5.4 · IC025 +1.8 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Multiple sclerosis relapse	40	13.1 9.7–17.8ROR 13.7 · χ² 437 / p 3e-97	12.8 EB05 9.6 · IC025 +3.0 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious PRR 32.4 · 98% consumer	no trial data cached
Burning sensation	34	11.0 7.9–15.3ROR 11.4 · χ² 300 / p 2e-67	10.5 EB05 7.6 · IC025 +2.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.3 · 94% consumer	no trial data cached
Hot flush (hot flashes)	31	9.3 6.6–13.2ROR 9.6 · χ² 223 / p 1e-50	8.6 EB05 6.2 · IC025 +2.4 3/3 methods agree	Labeled (related wording) related wording	serious PRR 10.2 · 90% consumer	no trial data cached
Skin burning sensation	18	5.7 3.6–9.1ROR 5.8 · χ² 66 / p 2e-16	5.0 EB05 3.4 · IC025 +1.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 10.9	no trial data cached
Multiple sclerosis	11	5.2 2.9–9.3ROR 5.2 · χ² 33 / p 4e-9	4.3 EB05 2.6 · IC025 +1.1 3/3 methods agree	Likely indication confounding term in indications	serious PRR 21.9	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
Flushing	348	77.4 71.2–84.2ROR 123.4 · χ² 26,215 / p <1e-300	76.9 EB05 70.3 · IC025 +5.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 47.2 · 92% consumer	no trial data cached
Feeling hot	41	15.1 11.2–20.4ROR 15.8 · χ² 528 / p 3e-117	14.9 EB05 11.4 · IC025 +3.2 3/3 methods agree	Not in label — unassessed	serious PRR 3.5 · 95% consumer	no trial data cached
Multiple sclerosis relapse	40	13.1 9.7–17.8ROR 13.7 · χ² 437 / p 3e-97	12.8 EB05 9.6 · IC025 +3.0 3/3 methods agree	Likely indication confounding shares a disease stem with the indications wording	serious PRR 32.4 · 98% consumer	no trial data cached
Burning sensation	34	11.0 7.9–15.3ROR 11.4 · χ² 300 / p 2e-67	10.5 EB05 7.6 · IC025 +2.7 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.3 · 94% consumer	no trial data cached
Hot flush (hot flashes)	31	9.3 6.6–13.2ROR 9.6 · χ² 223 / p 1e-50	8.6 EB05 6.2 · IC025 +2.4 3/3 methods agree	Labeled (related wording) related wording	serious PRR 10.2 · 90% consumer	no trial data cached
Skin burning sensation	18	5.7 3.6–9.1ROR 5.8 · χ² 66 / p 2e-16	5.0 EB05 3.4 · IC025 +1.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 10.9	no trial data cached
Multiple sclerosis	11	5.2 2.9–9.3ROR 5.2 · χ² 33 / p 4e-9	4.3 EB05 2.6 · IC025 +1.1 3/3 methods agree	Likely indication confounding term in indications	serious PRR 21.9	no trial data cached
Insurance issue	11	16.8 9.3–30.2ROR 17.0 · χ² 148 / p 3e-34	15.5 EB05 8.2 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 14.0	no trial data cached
Muscle spasticity	8	14.6 7.3–29.1ROR 14.7 · χ² 88 / p 3e-21	12.2 EB05 5.4 · IC025 +1.8 3/3 methods agree	Not in label — unassessed	–	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.

Feeling hot — n=41, PRR 15.1

✓ A hand-written Bradford Hill causality assessment exists for this drug: Tenofovir disoproxil fumarate ↔ Bone loss.

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 Monomethyl?

In FDA FAERS, the most frequently co-reported reaction terms for Monomethyl are flushing, feeling hot, multiple sclerosis relapse, burning sensation, hot flush, skin burning sensation. 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 Monomethyl have an FDA boxed warning?

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

Do FAERS signals prove that Monomethyl 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 a161f9d4-70f1-4097-957a-eafb35d3274f, effective 20260716; matched on openfda.generic_name.exact:"MONOMETHYL FUMARATE")
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, 9 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.