This grade answers one narrow question: how strong is the public evidence and safety record behind this drug, and how clean is its money trail and court record? It is not a verdict on whether the drug is right for you.
Memantine, an NMDA glutamate receptor antagonist, can cause neuropsychiatric disorders (hallucinations, confusion, dizziness or headache), sometimes leading to violent behaviour, seizures, psychotic disorders, as well as heart failure or bradyarrhythmia (Prescrire Int n° 204, 225, 227; Rev Prescrire n° 359, 398). Multiple sclerosis. The standard “disease-modifying” treatment for multiple sclerosis is interferon beta , despite its limitations and many adverse effects. The harm-benefit balance of the other “disease-modifying” treatments is no better and sometimes clearly unfavourable. This appli...
Prescrire is a French independent review funded only by subscribers, with no industry money. Its annual "drugs to avoid" list (2026 edition, section: Infectious diseases) names drugs it judges more harmful than useful in every authorised indication. Its view is one expert opinion, reached without a conflict of interest.
Memantine hydrochloride is indicated for the treatment of moderate to severe dementia of the Alzheimer's type. Memantine HCl is an N-methyl-D-aspartate (NMDA) receptor antagonist indicated for the treatment of moderate to severe dementia of the Alzheimer's type. ( 1 )
Memantine hydrochloride is contraindicated in patients with known hypersensitivity to memantine hydrochloride or to any excipients used in the formulation. Memantine HCl is contraindicated in patients with known hypersensitivity to memantine hydrochloride or to any excipients used in the formulation. ( 4 )
Conditions that raise urine pH may decrease the urinary elimination of memantine, resulting in increased plasma levels of memantine. ( 5.1 , 7.1 ) 5.1 Genitourinary Conditions Conditions that raise urine pH may decrease the urinary elimination of memantine resulting in increased plasma levels of memantine [see Drug Interactions ( 7.1 )] .
Most common adverse reactions (≥ 5 % and greater than placebo) are dizziness, headache, confusion and constipation. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Actavis at 1-800-272-5525 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Memantine HCl was evaluated in eight double-blind placebo-controlled trials involving a total of 1862 dementia (Alzheimer's disease, vascular dementia) patients (940 patients treated with Memantine HCl and 922 patients treated with placebo) for a treatment period up to 28 weeks. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Adverse Events Leading to Discontinuation In placebo-controlled trials in which dementia patients received doses of Memantine HCl up to 20 mg/day, the likelihood of discontinuation because of an adverse reaction was the same in the Memantine HCl group (10.1%) as in the placebo group (11.5%). No individual adverse reaction was associated with the discontinuation of t...
Source: FDA SPL label for memantine hydrochloride (Aphena Pharma Solutions - Tennessee, LLC), effective 20171130. Full label on DailyMed.
These are counts of reports people filed, not rates of harm. Anyone can file one, and nobody checks whether the drug was the cause. Millions of doses are taken for every report sent, so the useful part is how this drug compares with the average across all drugs.
| 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|
| 1,806 | 1,812 | 1,542 | 1,543 | 1,476 | 1,650 | 1,666 | 803 |
651 reports blaming this drug for every million Medicare prescriptions filled, which is 0.2× the typical drug on this site. (4,093 reports in 2024–2026, against 6,282,503 Medicare fills in one year. This is the one number here that accounts for how many people take the drug.)
Source: the FDA's Adverse Event Reporting System (FAERS). Reports are voluntary and unverified. Drugs that are prescribed a lot, in the news, or in lawsuits attract more reports, so the percentages are compared with the whole database to correct for that partly, not fully.
| Date | Class | Firm | Reason |
|---|---|---|---|
| 02/2020 | Class II | Lupin Pharmaceuticals Inc. | Failed Dissolution Specifications: Low out of specification results observed in dissolution test at six-month long-term stability study. |
| 12/2019 | Class III | Lupin Pharmaceuticals Inc. | Failed Dissolution Specifications: High out of specification result observed at stability studies. |
Class I = reasonable probability of serious harm. Class II = temporary or reversible harm. Class III = unlikely to harm. Most generic recalls are manufacturing or labeling defects for one lot, not a verdict on the molecule.
Counts measure how much evidence exists and how transparent it is, not how big the benefit is. For that, ask your prescriber: if 100 people like me took this, how many would get better because of it, and how many would be harmed? (Doctors call these the "number needed to treat" and "number needed to harm.") It differs by condition and is the number drug ads leave out. Sources: PubMed, ClinicalTrials.gov.
In 2024, drug companies reported $0 in payments to US physicians and hospitals tied to this drug across 0 transactions.
No pending federal MDL names this drug or its brands.
Not named in any federal pharmaceutical settlement of $100M or more on record.
Sources: CMS Open Payments (Sunshine Act); Judicial Panel on Multidistrict Litigation pending docket list; DOJ settlements as tabulated on Wikipedia with links to the primary record. State-court and individual suits are not included.
| Product | Fills | $/fill |
|---|---|---|
| Memantine HCl | 5,630,610 | $30 |
| Memantine HCl ER | 650,504 | $98 |
| Namenda XR | 1,148 | $608 |
| Namenda | 241 | $321 |
No same-class alternatives found in RxClass.