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.
How to Take It
Start by taking 5 mg of memantine once a day. Your doctor may increase the dose by 5 mg each week. The usual effective dose is 10 mg twice a day. You can take memantine with or without food.
This is a plain-language summary of memantine's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
It is not known if memantine can harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if memantine passes into breast milk, so talk to your doctor if you are breastfeeding.
This is a plain-language summary of memantine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses at the same time.
This is a plain-language summary of memantine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store memantine tablets at room temperature, between 68° to 77°F (20° to 25°C).
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
- Falling
Falling
937 reports
- Death
Death
853 reports
- Confusion
Confusion
707 reports
- Tiredness
Tiredness
605 reports
- Seeing or hearing things that are not there
Seeing or hearing things that are not there
581 reports
- Condition got worse
Condition got worse
502 reports
- Weakness
Weakness
469 reports
- Sleepiness
Sleepiness
438 reports
- Feeling dizzy
Feeling dizzy
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) 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.
What to do: Use this combination with caution and only if your doctor says it is necessary. Watch for any unusual changes in how you feel and report them to your provider.
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.
What to do: Your doctor should monitor you for increased side effects from memantine while taking these together.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
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?
Is memantine safe during pregnancy?
Has memantine been recalled?
Is memantine currently in shortage?
Active Recalls
Failed Dissolution Specifications
The Harvard Drug Group LLC
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Medication Guides
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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 further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
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. Always consult a healthcare professional before making medication decisions.
Last updated: August 17, 2023
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 and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
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