symmetrel

How long does Amantadine Hydrochloride stay in your body?

The elimination half-life of amantadine hydrochloride 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 — the time it takes the body to clear about half of it. As a rule of thumb, a medicine is mostly gone after roughly 4 to 5 half-lives, though this varies from person to person with age and kidney or liver function. 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.

This is general information, not medical advice. It doesn’t tell you when a drug test would read negative (tests detect substances for different, often longer, windows) or when it’s safe to take another dose — ask your pharmacist or prescriber. Source: Amantadine Hydrochloride FDA label (DailyMed) — Clinical Pharmacology, Pharmacokinetics.

Frequently asked questions

What does Symmetrel treat?

Symmetrel (Amantadine Hydrochloride) may be used to treat drug-induced dyskinesia, dystonia, human influenza, parkinson disease, secondary parkinson disease, drug-induced akathisia, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.

How is Symmetrel rated?

pharmaranks gives Symmetrel a composite score of 3.6 out of 5, currently based on 1 weighted source (FDA regulatory recall-safety data weighted highest). See our methodology at /how-we-rate.

How much does Symmetrel cost?

Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $4.67 for 30, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins.

Is there a coupon or discount for Symmetrel?

pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Symmetrel. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.

Who makes Symmetrel?

Symmetrel is marketed by Endo Pharms. You can see Endo Pharms's full profile, rating, and other products on pharmaranks.

Is Symmetrel a brand-name or generic drug?

Symmetrel is a brand-name product with the active ingredient Amantadine Hydrochloride. Lower-cost generic equivalents containing Amantadine Hydrochloride are available — ask your pharmacist.

Is Symmetrel available over the counter?

No. Symmetrel is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.

What forms does Symmetrel come in?

Symmetrel is currently marketed as syrup, tablet and capsule, per the FDA's National Drug Code Directory.

What class of drug is Symmetrel?

Symmetrel is classified as influenza a m2 protein inhibitor, per the FDA's Established Pharmacologic Class.

Is Symmetrel FDA-registered?

Symmetrel is on record with the U.S. FDA under application number NDA016020. You can verify this on its official FDA label.

Has Symmetrel been recalled by the FDA?

Symmetrel has no FDA recalls recorded under its own application in the openFDA enforcement database. Its recall-safety score reflects its manufacturer's overall recall record. This is general reference, not medical advice — check the FDA recall database for the latest alerts.

Is Symmetrel safe?

There's no single safe-or-not verdict. pharmaranks gives Symmetrel a recall-safety score of 72/100, based on its FDA recall history (no recalls under its own FDA application) — not an efficacy or side-effect rating. Review its FDA-label side effects and warnings before use, and always consult a licensed professional.