Amantadine: uses, dosing, side effects & brands
Amantadine is an influenza a m2 protein inhibitor sold in the U.S. under 4 brand and generic names, for drug-induced dyskinesia, dystonia and human influenza. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Influenza A M2 Protein Inhibitor
- Treats (across its forms)
- Drug-Induced Dyskinesia, Dystonia and Human Influenza
- Available as
- Syrup · Tablet · Capsule · Solution · Oral pellets · Tablet, extended release
- Sold as
- 4 products — Symmetrel, Amantadine Hydrochloride and Gocovri, and others
- Prescription?
- Prescription only
- Generic available?
- Yes
- Half-life
- about 17 hours (range roughly 10 to 25 hours); across studies it has averaged about 16 hours (range 9 to 31 hours) in healthy adults
- What the pharmacy pays
- about $5 for a 30-count supply — not your price
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How Gocovri is dosed
From the FDA label for Gocovri (application NDA208944). Other amantadine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Administer orally once daily at bedtime ( 2.1 , 2.3 ) The initial daily dosage is 137 mg; after 1 week, increase to the recommended daily dosage of 274 mg ( 2.1 ) Swallow whole; may sprinkle contents on soft food ( 2.2 ) May be taken with or without food; avoid use with alcohol ( 2.2 ) A lower dosage is recommended for patients with moderate or severe renal impairment ( 2.3 ) 2.1 Dosing Information The initial daily dosage of GOCOVRI is 137 mg, administered orally once daily at bedtime. After one week, increase to the recommended dosage of 274 mg (two 137 mg capsules) once daily at bedtime. GOCOVRI is not substitutable with other amantadine immediate- or extended-release products. 2.2 Administration Information GOCOVRI should be swallowed whole. Do not crush, chew or divide capsules. If needed, GOCOVRI may be administered by carefully opening and sprinkling the entire contents on a small amount (teaspoonful) of soft food, such as applesauce. The drug/food mixture should be swallowed immediately without chewing. Do not store mixture for future use. GOCOVRI can be taken with or without food [see Clinical Pharmacology ( 12.3 )]. Concomitant use of GOCOVRI with alcohol is not recommended [see Drug Interactions ( 7.4 )]. It is recommended to avoid sudden discontinuation of GOCOVRI [see Dosage and Administration ( 2.4 )]. 2.3 Dosing in Patients with Renal Impairment The initial and…
Everything below is the FDA label for Gocovri (capsule, oral pellets). Amantadine is also sold as syrup, tablet, solution and tablet, extended release, and those are different medicines to take — follow the label for the one you were prescribed.
Gocovri side effects
The following serious adverse reactions are described in more detail elsewhere in the labeling: Falling Asleep During Activities of Daily Living and Somnolence [see Warnings and Precautions ( 5.1 )] Suicidality and Depression [see Warnings and Precautions ( 5.2 )] Hallucinations/Psychotic Behavior [see Warnings and Precautions ( 5.3 )] Dizziness and Orthostatic Hypotension [see Warnings and Precautions ( 5.4 )] Withdrawal-Emergent Hyperpyrexia and Confusion [see Warnings and Precautions ( 5.5 )] Corneal Edema [see Warnings and Precautions ( 5.6 )] Impulse Control/Compulsive Behaviors [see Warnings and Precautions ( 5.7 )] The most commonly observed adverse reactions occurring at a frequency of >10% and greater than placebo were hallucination, dizziness, dry mouth, peripheral edema, constipation, fall, and orthostatic hypotension ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Supernus Pharmaceuticals, Inc. at 1-833-223-2627 or FDA at 1-800-FDA-1088 or http://www/fda.gov/medwatch. 6.1 Clinical Trial Experience 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 practice. Placebo-Controlled Trials GOCOVRI was evaluated in two double-blind, placebo-controlled efficacy trials…
Who shouldn’t take Gocovri
GOCOVRI is contraindicated in patients with end-stage renal disease (i.e., creatinine clearance below 15 mL/min/1.73 m 2 ) [see Clinical Pharmacology ( 12.3 )]. GOCOVRI is contraindicated in patients with end-stage renal disease ( 4 )
Gocovri drug interactions
Other Anticholinergic Drugs: Doses should be reduced if atropine-like effects occur ( 7.1 ) Drugs Affecting Urinary pH: Excretion increases with acidic urine; possible accumulation with urine change towards alkaline ( 7.2 ) Live Attenuated Influenza Vaccines: Not recommended during use ( 7.3 ) Alcohol: Concomitant use not recommended ( 7.4 ) 7.1 Other Anticholinergic Drugs Products with anticholinergic properties may potentiate the anticholinergic-like side effects of amantadine. The dose of anticholinergic drugs or of GOCOVRI should be reduced if atropine-like effects appear when these drugs are used concurrently. 7.2 Drugs Affecting Urinary pH The pH of the urine has been reported to influence the excretion rate of amantadine. Urine pH is altered by diet, drugs (e.g., carbonic anhydrase inhibitors, sodium bicarbonate), and clinical state of the patient (e.g., renal tubular acidosis or severe infections of the urinary tract). Since the excretion rate of amantadine increases rapidly when the urine is acidic, the administration of urine acidifying drugs may increase the elimination of the drug from the body. Alterations of urine pH towards the alkaline condition may lead to an accumulation of the drug with a possible increase in adverse reactions. Monitor for efficacy or adverse reactions under conditions that alter the urine pH to more acidic or alkaline, respectively. 7.3 Live Attenuated Influenza Vaccines Because of its antiviral properties, amantadine may interfere with the efficacy of live attenuated influenza vaccines. Therefore, live vaccines are not recommended during treatment with GOCOVRI. Inactivated influenza vaccines may be used, as appropriate. 7.4 Alcohol Concomitant use with alcohol is not recommended, as it may increase the potential for CNS effects such as dizziness, confusion, lightheadedness, and orthostatic hypotension [see Warnings and Precautions ( 5.4 )] , and may result in dose-dumping [see Clinical Pharmacology ( 12.3 )] .
Every amantadine product we track (4)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 72/100 | Prescription | Syrup | Generic | $5 | View → | |
| 2 | Not yet rated | Prescription | Solution | Generic | $5 | View → | |
| 3 | Not yet rated | Prescription | Capsule | Generic | $5 | View → | |
| 4 | Not yet rated | Prescription | Tablet | Generic | $5 | View → |
What amantadine pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Amantadine recalls
From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.
Can you crush or split amantadine?
At least one amantadineproduct is labelled to be swallowed whole — crushing an extended-release tablet releases the whole day’s dose at once. Which applies depends on the form you were given.
What each amantadine label says about crushing, splitting and chewingHow long amantadine keeps
No amantadine label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does amantadine expire? The in-use limits and storage rules from its labelsAmantadine and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for amantadine: levels in milk, effects in breastfed infants, and the drugs it would consider insteadIt is probably best to avoid amantadine during breastfeeding because of its potential negative effect on lactation. An alternative medication is recommended.
National Institute of Child Health and Human Development, record revised August 15, 2025. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about amantadine
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 2,174 reports naming amantadine, and the FDA flagged 75% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- fall175 reports
- gait disturbance154 reports
- fatigue136 reports
- hallucination134 reports
- speech disorder120 reports
- dyskinesia114 reports
- tremor102 reports
- constipation99 reports
Read these as a signal, not a rate. A report does not mean amantadine caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved August 25, 2026.
How long amantadine stays in your system
The elimination half-life of amantadine is about 17 hours (range roughly 10 to 25 hours); across studies it has averaged about 16 hours (range 9 to 31 hours) in healthy adults. Amantadine is excreted mostly unchanged in urine, so its half-life depends heavily on kidney function and age. In healthy elderly adults (age 60+) the half-life rises to about 29 hours (range 20 to 41 hours) as clearance falls. In renal impairment the elimination half-life increases two- to threefold or more when creatinine clearance is below 40 mL/min/1.73 m2, and averages about 8 days in patients on chronic maintenance hemodialysis (amantadine is removed only negligibly by hemodialysis). The label describes no active metabolite that outlasts the parent: the main metabolite, N-acetylamantadine (acetylamantadine), has an unknown contribution to efficacy or toxicity, and amantadine is not a prodrug. The label does not separate a distinct distribution phase, so the reported value is the terminal/elimination half-life.
Amantadine Hydrochloride FDA label (DailyMed) — Clinical Pharmacology, Pharmacokinetics ↗Half-life is how long the body takes to clear half a dose. It is not the same as how long a drug test can detect it, and it varies with age, kidney and liver function.
Related calculators
Frequently asked questions
What is Gocovri?
GOCOVRI contains amantadine in an extended-release formulation. The active ingredient in GOCOVRI is amantadine hydrochloride.
What kind of drug is amantadine?
The FDA classifies amantadine as an influenza a m2 protein inhibitor. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
How long does amantadine stay in your system?
The elimination half-life of amantadine is about 17 hours (range roughly 10 to 25 hours); across studies it has averaged about 16 hours (range 9 to 31 hours) in healthy adults — that is how long the body takes to clear half of a dose. Amantadine is excreted mostly unchanged in urine, so its half-life depends heavily on kidney function and age. In healthy elderly adults (age 60+) the half-life rises to about 29 hours (range 20 to 41 hours) as clearance falls. In renal impairment the elimination half-life increases two- to threefold or more when creatinine clearance is below 40 mL/min/1.73 m2, and averages about 8 days in patients on chronic maintenance hemodialysis (amantadine is removed only negligibly by hemodialysis). The label describes no active metabolite that outlasts the parent: the main metabolite, N-acetylamantadine (acetylamantadine), has an unknown contribution to efficacy or toxicity, and amantadine is not a prodrug. The label does not separate a distinct distribution phase, so the reported value is the terminal/elimination half-life. Half-life is not the same as how long a drug test can detect the drug, and it varies with age, kidney and liver function.
Can you take amantadine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run amantadine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is amantadine sold under?
We track 4 amantadine-containing products in the U.S.: Symmetrel, Amantadine Hydrochloride, Gocovri and Osmolex ER. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does amantadine come in?
Across the brands we track, amantadine is currently marketed as syrup, tablet, capsule, solution, oral pellets and tablet, extended release, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic amantadine?
Yes. Our catalog lists 1 generic amantadine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Has amantadine been recalled?
The FDA's Enforcement database lists 1 recall record whose product description mentions amantadine. The most recent: Amantadine HCl (Feb 13, 2026). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Amantadine: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/amantadine
- MLA
- “Amantadine: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/amantadine.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for amantadine on DailyMed (NIH) ↗.