Drug · FAERS side-effect profile with label screen
Memantine Hydrochloride side effects: what 2,764 FDA adverse event reports show
Drug class
N-methyl-d-aspartate (nmda) receptor antagonist
FDA label, Indications wording
Who reports
2,764 reports · 89% serious · 408 with death outcome · 54% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Memantine hydrochloride tablets are indicated for the treatment of moderate to severe dementia of the Alzheimer’s type. Memantine hydrochloride is an N-methyl-D-aspartate (NMDA) receptor antagonist indicated for the treatment of moderate to severe dementia of the Alzheimer’s type. ( 1 )
FDA label, Indications and Usage
What it is
Memantine hydrochloride is an orally active NMDA receptor antagonist.
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 40 strongest signals
Labeled adverse reaction 1Labeled (related wording) 1Likely indication confounding 3Reporting / coding artifact 2Not in label — unassessed 33
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. 1,014 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Body tinea | 56 | 169.9 129.0–223.8ROR 170.6 · χ² 8,306 / p <1e-300 | 145.4 EB05 116.2 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=33 · ♀ 100% (drug 54%) · 97% clinician | no trial data cached |
| Echolalia | 31 | 165.3 114.2–239.4ROR 165.7 · χ² 4,420 / p <1e-300 | 136.8 EB05 101.0 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Post-traumatic headache | 12 | 130.3 72.3–234.9ROR 130.4 · χ² 1,301 / p 3e-285 | 101.2 EB05 61.7 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Amyloid related imaging abnormality-oedema/effusion | 73 | 109.5 86.4–138.8ROR 110.1 · χ² 7,222 / p <1e-300 | 99.6 EB05 81.9 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=6 | no trial data cached |
| Eosinophilic pleural effusion | 19 | 104.6 65.8–166.5ROR 104.8 · χ² 1,729 / p <1e-300 | 89.4 EB05 60.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Amyloid related imaging abnormality-microhaemorrhages and haemosiderin deposits | 60 | 103.9 80.0–134.8ROR 104.3 · χ² 5,626 / p <1e-300 | 94.4 EB05 76.0 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=1 | no trial data cached |
| Pleurothotonus | 47 | 83.7 62.5–112.3ROR 84.0 · χ² 3,564 / p <1e-300 | 77.0 EB05 60.3 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=4 | no trial data cached |
| Myocardial oedema | 19 | 79.6 50.2–126.1ROR 79.7 · χ² 1,327 / p 8e-291 | 70.5 EB05 47.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Central pain syndrome | 11 | 66.6 36.4–121.8ROR 66.7 · χ² 620 / p 5e-137 | 57.8 EB05 34.4 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | – | no trial data cached |
| Inhibitory drug interaction | 53 | 53.1 40.4–69.8ROR 53.3 · χ² 2,568 / p <1e-300 | 50.5 EB05 40.1 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=32 · ♀ 100% (drug 54%) · 97% clinician | no trial data cached |
| Dementia with lewy bodies | 33 | 49.3 34.9–69.7ROR 49.4 · χ² 1,467 / p <1e-300 | 46.6 EB05 34.7 · IC025 +4.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=4 | no trial data cached |
| Frontotemporal dementia | 12 | 44.7 25.2–79.4ROR 44.7 · χ² 457 / p 1e-101 | 40.9 EB05 24.9 · IC025 +3.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | – | no trial data cached |
| Neuropsychological symptoms | 16 | 43.7 26.6–71.9ROR 43.8 · χ² 609 / p 1e-134 | 40.6 EB05 26.5 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=5 | no trial data cached |
| Infection susceptibility increased | 56 | 40.5 31.1–52.8ROR 40.7 · χ² 2,064 / p <1e-300 | 39.0 EB05 31.2 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=33 · ♀ 100% (drug 54%) · 97% clinician | no trial data cached |
| Electrocardiogram pr prolongation | 18 | 37.9 23.7–60.5ROR 37.9 · χ² 595 / p 9e-132 | 35.7 EB05 23.9 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Sialoadenitis | 27 | 31.3 21.4–45.7ROR 31.3 · χ² 746 / p 2e-164 | 30.1 EB05 21.7 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Intestinal pseudo-obstruction | 15 | 27.3 16.4–45.5ROR 27.3 · χ² 348 / p 6e-78 | 26.0 EB05 16.7 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=4 | no trial data cached |
| Product ineffective | 11 | 24.9 13.7–45.1ROR 24.9 · χ² 225 / p 3e-51 | 23.4 EB05 13.7 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Chorea | 23 | 20.7 13.8–31.3ROR 20.8 · χ² 407 / p 7e-91 | 20.1 EB05 14.0 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=4 | no trial data cached |
| Hyporesponsive to stimuli | 15 | 20.4 12.2–33.9ROR 20.4 · χ² 254 / p 2e-57 | 19.5 EB05 12.2 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Dementia | 337 | 18.9 17.0–21.0ROR 19.3 · χ² 5,623 / p <1e-300 | 18.6 EB05 17.0 · IC025 +4.0 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 10.2 | no trial data cached |
| Hyperglycaemic hyperosmolar nonketotic syndrome | 13 | 18.3 10.6–31.6ROR 18.3 · χ² 193 / p 3e-44 | 17.3 EB05 10.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=4 | no trial data cached |
| Moaning | 13 | 18.1 10.5–31.3ROR 18.1 · χ² 191 / p 1e-43 | 17.0 EB05 9.9 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=7 | no trial data cached |
| Catatonia | 59 | 17.6 13.6–22.8ROR 17.7 · χ² 898 / p 1e-197 | 17.3 EB05 13.9 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Bradyarrhythmia | 18 | 17.1 10.7–27.2ROR 17.1 · χ² 254 / p 2e-57 | 16.4 EB05 10.6 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=2 | no trial data cached |
| Atrioventricular block first degree | 47 | 16.8 12.6–22.4ROR 16.8 · χ² 675 / p 5e-149 | 16.5 EB05 12.8 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Illusion | 18 | 16.8 10.5–26.7ROR 16.8 · χ² 249 / p 2e-56 | 16.1 EB05 10.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Hallucinations, mixed | 45 | 16.6 12.4–22.3ROR 16.7 · χ² 639 / p 3e-141 | 16.3 EB05 12.6 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=5 | no trial data cached |
| Delusion | 163 | 16.4 14.1–19.1ROR 16.6 · χ² 2,316 / p <1e-300 | 16.2 EB05 14.2 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Hypernatraemia | 49 | 15.4 11.6–20.3ROR 15.4 · χ² 637 / p 7e-141 | 15.1 EB05 11.8 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=20 · 100% clinician | no trial data cached |
| Glucose tolerance impaired | 58 | 15.4 11.9–19.9ROR 15.4 · χ² 757 / p 7e-167 | 15.1 EB05 12.0 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=33 · ♀ 100% (drug 54%) · 97% clinician | no trial data cached |
| Nonspecific reaction | 51 | 14.7 11.2–19.4ROR 14.8 · χ² 632 / p 8e-140 | 14.4 EB05 11.3 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=2 | no trial data cached |
| Stoma site haemorrhage | 14 | 14.3 8.5–24.2ROR 14.3 · χ² 159 / p 1e-36 | 13.1 EB05 7.5 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Myoclonus | 106 | 13.8 11.4–16.7ROR 13.9 · χ² 1,237 / p 3e-271 | 13.6 EB05 11.5 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 · 95% clinician | no trial data cached |
| Hallucination, visual | 183 | 13.6 11.7–15.7ROR 13.7 · χ² 2,098 / p <1e-300 | 13.4 EB05 11.8 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | no trial data cached |
| Akinesia | 18 | 13.5 8.5–21.5ROR 13.5 · χ² 195 / p 2e-44 | 12.6 EB05 7.9 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=1 | no trial data cached |
| Hallucination (hallucinations) | 632 | 13.1 12.1–14.1ROR 13.7 · χ² 7,015 / p <1e-300 | 13.0 EB05 12.2 · IC025 +3.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.4 | no trial data cached |
| Sedation complication | 21 | 13.0 8.5–20.0ROR 13.1 · χ² 220 / p 5e-50 | 12.2 EB05 8.0 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious n=2 | no trial data cached |
| Stoma site discharge | 23 | 13.0 8.6–19.6ROR 13.1 · χ² 242 / p 9e-55 | 12.3 EB05 8.2 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=3 | no trial data cached |
| Posture abnormal | 27 | 12.9 8.8–18.8ROR 12.9 · χ² 282 / p 1e-63 | 12.3 EB05 8.5 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=2 | 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 |
|---|---|---|---|---|---|---|
| Fall | 996 | 4.6 4.4–4.9ROR 4.9 · χ² 2,866 / p <1e-300 | 4.6 EB05 4.4 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 3.3 | no trial data cached |
| Death | 916 | 1.6 1.5–1.7ROR 1.7 · χ² 238 / p 6e-54 | 1.6 EB05 1.6 · IC025 +0.6 | Outcome field, not a reaction | serious PRR 0.5 · ♀ 33% (drug 54%) | no trial data cached |
| Drug ineffective (drug did not work) | 861 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.413 | 1.0 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.1 | no trial data cached |
| Off label use (used outside approved label) | 782 | 1.4 1.3–1.5ROR 1.4 · χ² 88 / p 3e-21 | 1.4 EB05 1.3 · IC025 +0.4 | Reporting / coding artifact | serious PRR 1.0 | no trial data cached |
| Confusional state (confusion) | 739 | 7.1 6.6–7.6ROR 7.4 · χ² 3,852 / p <1e-300 | 7.0 EB05 6.6 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.4 | no trial data cached |
| Fatigue (tiredness) | 646 | 1.3 1.2–1.4ROR 1.3 · χ² 41 / p 7e-11 | 1.3 EB05 1.2 · IC025 +0.2 | Labeled adverse reaction exact term | serious PRR 1.5 | no trial data cached |
| Hallucination (hallucinations) | 632 | 13.1 12.1–14.1ROR 13.7 · χ² 7,015 / p <1e-300 | 13.0 EB05 12.2 · IC025 +3.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.4 | no trial data cached |
| Condition aggravated | 533 | 2.7 2.5–3.0ROR 2.8 · χ² 587 / p 5e-130 | 2.7 EB05 2.5 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 2.2 | no trial data cached |
| Asthenia (weakness) | 487 | 2.0 1.8–2.2ROR 2.0 · χ² 246 / p 1e-55 | 2.0 EB05 1.9 · IC025 +0.8 | Not in label — unassessed | serious PRR 2.3 | no trial data cached |
| Dizziness | 464 | 1.4 1.3–1.6ROR 1.5 · χ² 63 / p 1e-15 | 1.4 EB05 1.3 · IC025 +0.4 | Labeled adverse reaction exact term | serious PRR 1.3 | no trial data cached |
| Somnolence (drowsiness) | 462 | 3.5 3.2–3.9ROR 3.6 · χ² 849 / p 6e-187 | 3.5 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.3 | no trial data cached |
| Urinary tract infection (bladder infection) | 438 | 4.0 3.6–4.4ROR 4.1 · χ² 979 / p 4e-215 | 4.0 EB05 3.7 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Nausea | 422 | 0.8 0.8–0.9ROR 0.8 · χ² 16 / p 3e-5 | 0.8 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 1.1 | no trial data cached |
| Diarrhoea (diarrhea) | 407 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.313 | 1.0 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 0.9 | no trial data cached |
| Product dose omission issue | 364 | 2.0 1.8–2.2ROR 2.0 · χ² 175 / p 2e-40 | 2.0 EB05 1.8 · IC025 +0.8 | Reporting / coding artifact | serious PRR 1.2 · 87% consumer | 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.
- Body tinea — n=56, PRR 169.9
- Echolalia — n=31, PRR 165.3
- Amyloid related imaging abnormality-oedema/effusion — n=73, PRR 109.5
- Amyloid related imaging abnormality-microhaemorrhages and haemosiderin deposits — n=60, PRR 103.9
- Pleurothotonus — n=47, PRR 83.7
- Inhibitory drug interaction — n=53, PRR 53.1
- Infection susceptibility increased — n=56, PRR 40.5
- Sialoadenitis — n=27, PRR 31.3
- Chorea — n=23, PRR 20.7
- Catatonia — n=59, PRR 17.6
✓ A hand-written Bradford Hill causality assessment exists for this drug: Memantine ↔ Confusional state.
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 Memantine?
In FDA FAERS, the most frequently co-reported reaction terms for Memantine are fall, confusional state, fatigue, hallucination, asthenia, dizziness. 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 Memantine have an FDA boxed warning?
No. The FDA label retrieved for Memantine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Memantine 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 304a3059-4f7f-4ec4-839d-86492bb5e07b, effective 20250422; matched on
openfda.generic_name.exact:"MEMANTINE") - 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, 1,054 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.