Prescription medication · NMDA Receptor Antagonist
memantine
Also sold as Namenda. Memantine is used to treat moderate to severe Alzheimer's disease.
Data updated 2026-05-15
- 12,807
- FDA reportsModerately reported
- 2
- InteractionsFew interactions
- In shortage
- FDA status
What the data shows
memantine (Namenda) is a prescription NMDA Receptor Antagonist, reported less often than most tracked drugs (12,807 FDA reports), with 2 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
memantine (Namenda) is a prescription NMDA Receptor Antagonist. Memantine is used to treat moderate to severe Alzheimer's disease.
Memantine is a medicine used to treat moderate to severe Alzheimer's disease. It may help with memory and thinking.
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
memantine is currently listed as to be discontinued by the FDA. Affected manufacturer: Upsher-Smith Laboratories, LLC.
View all drug shortages →Drug Pricing (NADAC)
Generic Price
$0.32/unit
Generic Available
Yes (31 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Memantine is used to treat moderate to severe Alzheimer's disease.
Common side effects
Dizziness, Headache, Confusion
Key warnings
If you have conditions that make your urine less acidic (more alkaline), memantine levels in your blood may increase.
The sections below are summarized in plain English from memantine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Memantine is an NMDA receptor antagonist. This means it blocks the effects of a chemical in the brain called glutamate. By blocking glutamate, memantine may help protect brain cells from damage.
Side Effects (from patient reports)
Based on 12,807 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for memantine, by number of reports
- Fall
Fall
937 reports
- Death
Death
853 reports
- Confusional State
Confusional State
706 reports
- Fatigue
Fatigue
605 reports
- Hallucination
Hallucination
581 reports
- Condition Aggravated
Condition Aggravated
502 reports
- Asthenia
Asthenia
469 reports
- Somnolence
Somnolence
438 reports
- Dizziness
Dizziness
436 reports
- Urinary Tract Infection
Urinary Tract Infection
420 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for memantine each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where memantine sits
memantine has more FDA adverse-event reports than 45% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is memantine; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 12,807 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
12,807
Reports Mentioning Death
1,934
15.1% of reports — not proof of cause
Hospitalization Reports
5,255
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | FALL | 937 |
| 2 | DEATH | 853 |
| 5 | CONFUSIONAL STATE | 706 |
| 6 | FATIGUE | 605 |
| 7 | HALLUCINATION | 581 |
| 8 | CONDITION AGGRAVATED | 502 |
| 9 | ASTHENIA | 469 |
| 10 | SOMNOLENCE | 438 |
| 11 | DIZZINESS | 436 |
| 12 | URINARY TRACT INFECTION | 420 |
| 13 | NAUSEA | 404 |
| 14 | DIARRHOEA | 379 |
| 15 | GAIT DISTURBANCE | 346 |
| 16 | AGITATION | 344 |
| 18 | PNEUMONIA | 321 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
If you have conditions that make your urine less acidic (more alkaline), memantine levels in your blood may increase. This could increase the risk of side effects. Talk to your doctor if you have kidney problems or take medicines that affect urine pH.
Known Drug Interactions
7.2 Use with Other N-methyl-D-aspartate (NMDA) Antagonists The combined use of memantine hydrochloride with other NMDA antagonists (amantadine, ketamine, and dextromethorphan) has not been systematically evaluated and such use should be approached with caution.
Mechanism: Both of these drugs affect the same receptors in the brain, and using them together has not been well studied. This could cause unknown side effects or change how the medications work.
Cases of interactions with other OCT2 substrates, memantine and metformin, have also been reported.
Mechanism: Both drugs use the same pathway in the kidneys to leave the body. This can cause memantine to build up in the blood because the kidneys are busy processing the trimethoprim.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
What should I avoid while taking memantine?
Can I drive while taking memantine?
How long will I need to take memantine?
What if I have kidney problems?
Can memantine cure Alzheimer's disease?
What happens if I stop taking memantine?
Are there any foods I should avoid?
Can I take memantine with other Alzheimer's medications?
What should I do if I think I'm experiencing a side effect?
Is there a generic version of memantine?
What are the common side effects of memantine?
Does memantine interact with other medications?
What drug class is memantine?
What pregnancy or breastfeeding source fields are listed for memantine?
Has memantine been recalled?
Is memantine currently in shortage?
Active Recalls
Failed Dissolution Specifications
The Harvard Drug Group LLC
Related Medications in NMDA Receptor Antagonist
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amitriptyline
Elavil
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amphetamine/dextroamphetamine
Adderall, Adderall XR
Adderall XR is a stimulant medicine.
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aripiprazole
Abilify
Aripiprazole (Abilify) is a medicine used to treat certain mental disorders and mood problems.
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Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for memantine: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 12,807.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 15.10%.
- oseltamivir Δ 0.07 pts · 7,575 reports · Neuraminidase Inhibitor (Antiviral) 15.17%death share
- sildenafil Δ 0.07 pts · 55,325 reports · PDE5 Inhibitor 15.17%death share
- entacapone Δ 0.15 pts · 3,955 reports · COMT Inhibitor 15.25%death share
- senna Δ 0.24 pts · 20,197 reports · Stimulant Laxative 15.34%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for memantine
The FDA label for memantine (sold under brand names such as Namenda) classifies it as a prescription-only medication in the NMDA Receptor Antagonist class. Memantine is used to treat moderate to severe Alzheimer's disease. Official labeling lists 4 commonly reported side effects, including Dizziness, Headache, Confusion.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 12,807 voluntary reports. The database also lists 2 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.32.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: August 17, 2023
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages