Drug · FAERS side-effect profile with label screen
Memantine Hydrochloride Oral 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 1Reporting / coding artifact 1Lab value / disease marker 1Not in label — unassessed 35
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. 99 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 |
|---|---|---|---|---|---|---|
| Sopor | 45 | 25.6 19.2–34.3ROR 26.0 · χ² 1,037 / p 7e-228 | 25.3 EB05 19.7 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 16.5 | no trial data cached |
| Hyperlipidaemia | 34 | 21.6 15.4–30.2ROR 21.8 · χ² 645 / p 1e-142 | 21.3 EB05 15.9 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 15.3 · ♀ 96% (drug 54%) · 97% clinician | no trial data cached |
| Pneumonia aspiration | 58 | 17.7 13.7–22.8ROR 18.1 · χ² 896 / p 4e-197 | 17.5 EB05 14.0 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 11.2 | no trial data cached |
| Orthostatic hypotension (dizziness on standing) | 40 | 17.4 12.8–23.7ROR 17.7 · χ² 602 / p 3e-133 | 17.2 EB05 13.1 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 12.8 · 100% clinician | no trial data cached |
| Impaired quality of life | 31 | 16.4 11.5–23.2ROR 16.6 · χ² 432 / p 4e-96 | 16.1 EB05 11.7 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 15.2 · ♀ 92% (drug 54%) · 97% clinician | no trial data cached |
| Sinus bradycardia | 20 | 15.7 10.1–24.3ROR 15.8 · χ² 260 / p 7e-59 | 15.2 EB05 10.0 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.4 · 100% clinician | no trial data cached |
| Dementia | 56 | 15.3 11.8–19.8ROR 15.6 · χ² 733 / p 1e-161 | 15.1 EB05 12.0 · IC025 +3.3 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 10.2 | no trial data cached |
| Metastases to central nervous system | 24 | 14.2 9.6–21.2ROR 14.4 · χ² 282 / p 1e-63 | 13.7 EB05 9.4 · IC025 +2.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 9.3 | no trial data cached |
| Myoclonus | 22 | 14.0 9.2–21.3ROR 14.1 · χ² 253 / p 3e-57 | 13.4 EB05 8.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 · 95% clinician | no trial data cached |
| Poor quality sleep | 38 | 13.5 9.8–18.5ROR 13.7 · χ² 427 / p 4e-95 | 13.2 EB05 9.8 · IC025 +3.0 3/3 methods agree | Reporting / coding artifact | serious PRR 15.6 · ♀ 93% (drug 54%) · 92% clinician | no trial data cached |
| Neuroleptic malignant syndrome | 21 | 13.4 8.8–20.6ROR 13.5 · χ² 229 / p 5e-52 | 12.7 EB05 8.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 8.7 · 100% clinician | no trial data cached |
| Oral herpes | 33 | 12.9 9.2–18.1ROR 13.0 · χ² 350 / p 2e-78 | 12.5 EB05 9.1 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 19.5 · ♀ 100% (drug 54%) · 97% clinician | no trial data cached |
| Salivary hypersecretion | 16 | 12.2 7.5–19.8ROR 12.2 · χ² 153 / p 2e-35 | 11.0 EB05 6.6 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 | no trial data cached |
| Inappropriate antidiuretic hormone secretion | 16 | 11.9 7.3–19.5ROR 12.0 · χ² 149 / p 1e-34 | 10.8 EB05 6.5 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.8 | no trial data cached |
| Delusion | 24 | 11.8 7.9–17.5ROR 11.9 · χ² 226 / p 3e-51 | 11.0 EB05 7.5 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Psychomotor hyperactivity | 24 | 10.9 7.3–16.3ROR 11.0 · χ² 207 / p 4e-47 | 10.1 EB05 6.9 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 10.7 · 92% clinician | no trial data cached |
| Brain oedema | 18 | 10.8 6.8–17.2ROR 10.9 · χ² 151 / p 6e-35 | 9.7 EB05 6.1 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Delirium | 47 | 10.3 7.8–13.7ROR 10.5 · χ² 387 / p 2e-86 | 9.9 EB05 7.6 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.8 | no trial data cached |
| Bradycardia (slow heart rate) | 72 | 10.3 8.2–12.9ROR 10.5 · χ² 596 / p 8e-132 | 10.0 EB05 8.2 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.8 · 96% clinician | no trial data cached |
| Impaired work ability | 28 | 9.9 6.9–14.3ROR 10.0 · χ² 216 / p 4e-49 | 9.2 EB05 6.5 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 8.2 · ♀ 100% (drug 54%) · 100% clinician | no trial data cached |
| Hypothermia | 13 | 9.7 5.7–16.7ROR 9.8 · χ² 93 / p 2e-22 | 8.1 EB05 4.7 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 | no trial data cached |
| Hypophagia | 32 | 9.6 6.8–13.5ROR 9.7 · χ² 237 / p 7e-54 | 8.9 EB05 6.5 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 7.3 | no trial data cached |
| Mental status changes | 35 | 9.6 6.9–13.3ROR 9.7 · χ² 260 / p 9e-59 | 9.0 EB05 6.6 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 · 96% clinician | no trial data cached |
| Aspiration | 13 | 9.1 5.3–15.7ROR 9.2 · χ² 86 / p 1e-20 | 7.5 EB05 4.5 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 | no trial data cached |
| Ataxia | 14 | 8.9 5.3–15.0ROR 9.0 · χ² 91 / p 9e-22 | 7.5 EB05 4.5 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Cerebral haemorrhage | 39 | 8.3 6.1–11.3ROR 8.4 · χ² 243 / p 5e-55 | 7.7 EB05 5.8 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 | no trial data cached |
| Skin disorder | 36 | 8.2 5.9–11.4ROR 8.3 · χ² 221 / p 3e-50 | 7.6 EB05 5.7 · IC025 +2.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.9 · ♀ 100% (drug 54%) · 94% clinician | no trial data cached |
| Malnutrition | 12 | 8.2 4.7–14.4ROR 8.2 · χ² 69 / p 5e-17 | 6.6 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.5 | no trial data cached |
| Hallucination, auditory | 17 | 8.1 5.0–13.0ROR 8.2 · χ² 99 / p 1e-23 | 7.0 EB05 4.5 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.1 | no trial data cached |
| Squamous cell carcinoma | 10 | 8.1 4.3–15.0ROR 8.1 · χ² 55 / p 6e-14 | 6.3 EB05 3.5 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.4 | no trial data cached |
| Agitation | 78 | 8.0 6.5–10.0ROR 8.2 · χ² 475 / p 1e-105 | 7.8 EB05 6.4 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Bone density decreased | 33 | 7.9 5.6–11.1ROR 8.0 · χ² 192 / p 5e-44 | 7.3 EB05 5.4 · IC025 +2.3 3/3 methods agree | Lab value / disease marker | serious PRR 6.4 · ♀ 100% (drug 54%) · 97% clinician | no trial data cached |
| Presyncope (near-fainting) | 24 | 7.5 5.1–11.2ROR 7.6 · χ² 129 / p 3e-30 | 6.7 EB05 4.7 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · 100% clinician | no trial data cached |
| Hypertensive crisis | 11 | 7.5 4.1–13.5ROR 7.5 · χ² 55 / p 5e-14 | 6.0 EB05 3.5 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | no trial data cached |
| Subarachnoid haemorrhage | 10 | 7.4 4.0–13.8ROR 7.5 · χ² 49 / p 1e-12 | 5.8 EB05 3.3 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | no trial data cached |
| Dyskinesia (involuntary movements) | 39 | 7.3 5.3–10.0ROR 7.4 · χ² 206 / p 5e-47 | 6.8 EB05 5.2 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 | no trial data cached |
| Hallucination, visual | 20 | 7.2 4.7–11.2ROR 7.3 · χ² 101 / p 4e-24 | 6.3 EB05 4.3 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.8 | no trial data cached |
| Decreased activity | 10 | 7.1 3.8–13.2ROR 7.1 · χ² 46 / p 5e-12 | 5.6 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Abnormal behaviour | 35 | 6.7 4.8–9.3ROR 6.7 · χ² 163 / p 1e-37 | 6.2 EB05 4.6 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 | no trial data cached |
| Gastric haemorrhage | 10 | 6.6 3.5–12.2ROR 6.6 · χ² 42 / p 5e-11 | 5.2 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 | 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 | 190 | 4.3 3.8–5.0ROR 4.6 · χ² 492 / p 2e-109 | 4.3 EB05 3.8 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.3 | no trial data cached |
| Confusional state (confusion) | 125 | 5.9 4.9–7.0ROR 6.1 · χ² 503 / p 1e-111 | 5.7 EB05 4.9 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.4 | no trial data cached |
| Somnolence (drowsiness) | 112 | 4.2 3.5–5.1ROR 4.4 · χ² 275 / p 4e-62 | 4.2 EB05 3.6 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.3 | no trial data cached |
| Agitation | 78 | 8.0 6.5–10.0ROR 8.2 · χ² 475 / p 1e-105 | 7.8 EB05 6.4 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Syncope (fainting) | 77 | 5.8 4.7–7.3ROR 6.0 · χ² 305 / p 1e-68 | 5.6 EB05 4.7 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | no trial data cached |
| Dehydration | 74 | 4.2 3.4–5.3ROR 4.3 · χ² 179 / p 4e-41 | 4.1 EB05 3.4 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.1 | no trial data cached |
| Bradycardia (slow heart rate) | 72 | 10.3 8.2–12.9ROR 10.5 · χ² 596 / p 8e-132 | 10.0 EB05 8.2 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.8 · 96% clinician | no trial data cached |
| Hallucination (hallucinations) | 63 | 6.4 5.0–8.1ROR 6.5 · χ² 281 / p 2e-63 | 6.1 EB05 4.9 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.4 | no trial data cached |
| Pneumonia aspiration | 58 | 17.7 13.7–22.8ROR 18.1 · χ² 896 / p 4e-197 | 17.5 EB05 14.0 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 11.2 | no trial data cached |
| Dysphagia (difficulty swallowing) | 57 | 4.6 3.5–5.9ROR 4.6 · χ² 156 / p 4e-36 | 4.4 EB05 3.5 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Loss of consciousness | 56 | 3.3 2.6–4.3ROR 3.4 · χ² 89 / p 2e-21 | 3.2 EB05 2.6 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Dementia | 56 | 15.3 11.8–19.8ROR 15.6 · χ² 733 / p 1e-161 | 15.1 EB05 12.0 · IC025 +3.3 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 10.2 | no trial data cached |
| Hyponatraemia (low sodium) | 47 | 6.3 4.8–8.4ROR 6.4 · χ² 207 / p 3e-47 | 6.0 EB05 4.7 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | no trial data cached |
| Delirium | 47 | 10.3 7.8–13.7ROR 10.5 · χ² 387 / p 2e-86 | 9.9 EB05 7.6 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.8 | no trial data cached |
| Sopor | 45 | 25.6 19.2–34.3ROR 26.0 · χ² 1,037 / p 7e-228 | 25.3 EB05 19.7 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 16.5 | 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.
- Sopor — n=45, PRR 25.6
- Hyperlipidaemia — n=34, PRR 21.6
- Pneumonia aspiration — n=58, PRR 17.7
- Orthostatic hypotension — n=40, PRR 17.4
- Impaired quality of life — n=31, PRR 16.4
- Sinus bradycardia — n=20, PRR 15.7
- Myoclonus — n=22, PRR 14.0
- Neuroleptic malignant syndrome — n=21, PRR 13.4
- Oral herpes — n=33, PRR 12.9
- Delusion — n=24, PRR 11.8
✓ 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, somnolence, agitation, syncope, dehydration. 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, 139 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.