HomeNDC LookupIngredientsAmantadine Hydrochloride › 42543-0497-05
Amantadine Hydrochloride 100 mg Tablet, 500-count — NDC 42543-0497-05 package photo

Amantadine Hydrochloride 100 mg Tablet, 500-count

by Strides Pharma Inc. · 500 TABLET in 1 BOTTLE (42543-497-05)
NDC 42543-0497-05
🏷️ FDA NDC (as labeled) 42543-497-05 billing pads the product segment with a zero
This package
Contains500-count Cost per ea$0.3115 NADAC Per package$155.75 / 500 tablets Pack sizes2 compare ↓
Also priced by: Medicaid pays $0.3860/unit · Part D plans $0.5201/unit — full pricing hub ↓
Also comes in: 100 tablets 42543-0497-01
Rx only Generic On market Non-controlled
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →
⚠️
Other active recalls for Amantadine Hydrochloride (different manufacturers) — 1 · tap to view
These affect other manufacturers’ products for the same ingredient — not necessarily the exact NDC on this page.
Class II · Feb 13, 2026 — Failed Dissolution Specifications: This recall has been initiated due to an Out of Specification finding in dissolution. (AvKARE) · FDA recall D-0341-2026
Each entry is an official FDA enforcement report — look up any recall number in the FDA recall database ↗

🆔 Identity & classification

FDA NDC (as labeled) 42543-497-05
Product NDC 42543-497
11-digit billing NDC 42543049705
NCPDP billing unit EA — each (per item)
RxCUI 849395
UNII M6Q1EO9TD0
UPC 0342543497016
Application # ANDA209035
SPL Set ID 9a99bb98-82a4-4b9e-9216-554dade72a3c
Established class (EPC) Influenza A M2 Protein Inhibitor
Mechanism of action M2 Protein Inhibitors
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2017-08-04
Route ORAL
Dosage form TABLET
Substance AMANTADINE HYDROCHLORIDE
GPI-14 73200010100310
GPI class Amantadine HCl
GCN Seq No 027637
GCN 17521
HICL code 001898
Ingredient (HICL) Amantadine Hcl
HIC1 code H
Therapeutic class — broad (HIC1) Nervous System (Except Autonomic)
HIC2 code H6
Therapeutic class — intermediate (HIC2) Drugs Acting Principally On The Midbrain
HIC3 code H6A
Therapeutic class — specific (HIC3) Antiparkinsonism Drugs,Other
AHFS code 08:18.04.00
AHFS class Adamantane Antivirals
FDB label name AMANTADINE 100 MG TABLET
FDB brand name Amantadine
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 42543-497-05 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 42543-0497-05. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Influenza A M2 Protein Inhibitor class.

Pharmacologic class Influenza A M2 Protein Inhibitor
Drug family (ATC) Adamantane derivatives
How it works M2 Protein Inhibitors
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerStrides Pharma Inc.
Application holderSTRIDES PHARMA GLOBAL PTE LTD
FDA applicationANDA209035 (ANDA)
Labeler code42543
First marketedAug 2017
Product typeHuman Prescription Drug
Portfolio21 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

Label name AMANTADINE 100 MG TABLET Ingredient Amantadine Hcl
📗 Our plain-language guide HelloPharmacist
  • Amantadine only works against influenza A — it won't help with influenza B, COVID-19, colds, or stomach bugs. And it works best for the flu when you start it early in the illness....
  • Can I take amantadine to treat a regular flu or a stomach bug?
  • The ones that matter most are hallucinations (seeing or hearing things that aren't there), significant dizziness — especially when you stand up — and any vision changes like sudden...
  • I take amantadine for Parkinson's — what side effects should I actually watch for?
📖 Read our full Amantadine guide →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

💊 What it looks like

Color Orange
ShapeRound
ImprintS;502
Size7 mm
ScoringNot scored
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII OP1R32D61U
    Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
  • UNII H77VEI93A8
    A synthetic yellow dye used to color medications. It helps identify the drug and make it visually distinctive, with no effect on how the medicine works.
  • UNII 70097M6I30
    Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
  • UNII U725QWY32X
    Povidone K30 is a synthetic polymer made from petroleum. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in the stomach so the medicine can be absorbed.
  • UNII ETJ7Z6XBU4
    Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
  • UNII 5856J3G2A2
    A starch-based powder made from potatoes and processed with sodium. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the medicine can be absorbed.

6 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMedingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer eaPer package
Retail pharmacies payNADAC · weekly $0.312 $155.75 / 500 tablets
Medicaid paysCMS SDUD · 12 mo $0.3860 $193.00 / 500 tablets
Medicare drug plans payPart D · Q2 2026 $0.5201 $260.05 / 500 tablets
NADAC price history (per ea) — tap or hover for the price & month
Dec 2021 Jul 2022 Dec 2025 Aug 2026 $0.819 $0.295
▼ Down 55% over the last 24 months.
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Amantadine Hydrochloride 100 mg 00832-0111-00 Upsher-Smith 100 tablets $0.311 AB Availability likely
Amantadine Hydrochloride 100 mgthis 42543-0497-05 Strides 500 tablets $0.311 AB Availability likely
Amantadine 100 mg 62332-0586-31 Alembic 100 tablets $0.311 AB Availability likely
Amantadine Hydrochloride 100 mg 00591-4920-01 Actavis 100 tablets $0.315 Discontinued +1%
Amantadine 100 mg 00615-8605-39 NCS 30 tablets AB FDA listed
Amantadine Hydrochloride 100 mg 10135-0692-01 Marlex 100 tablets AB FDA listed
Amantadine 100 mg 46708-0586-31 Alembic 100 tablets AB FDA listed
Amantadine Hydrochloride 100 mg 67046-1452-03 Coupler 30 tablets AB FDA listed
Amantadine 100 mg 67046-1531-03 Coupler 30 tablets AB FDA listed
Amantadine Hydrochloride 100 mg 71765-0009-01 Zhejiang 24 tablets AB FDA listed
Amantadine HCL 100 mg 72189-0535-30 Direct_Rx 30 tablets AB FDA listed
Amantadine 100 mg 82804-0267-20 Proficient 20 tablets AB FDA listed
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2017
On the market since
Aug 2017
📍
2026
Currently FDA-listed
9 years listed
🔓
·
Generic on the market
this product is a generic
This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

🗺️ Medicaid utilization & spend

📍 This exact package only: Medicaid data is reported per full 11-digit NDC — labeler, product and pack size — so every number here is for 42543-0497-05, not the drug overall. Other pack sizes report separately.
💊 Pharmacy benefit only: These are Medicaid outpatient pharmacy claims, billed by NDC. They exclude the medical benefit — clinic- or hospital-administered drugs billed under HCPCS J-codes — so drugs used mostly that way (e.g. Avastin, Lucentis, Keytruda) can look low or missing here. That’s expected, not an error.
📅 Q1 2025 – Q4 2025 · 4 quarters of data
ⓘ The newest quarter is usually incomplete when first published; states restate recent quarters in later CMS releases, so the latest figures typically revise upward. State coverage-policy changes can also shift quarter-to-quarter totals.
Prescriptions last 4 qtrs
29K
Units reimbursed last 4 qtrs
2.4M
Gross reimbursed last 4 qtrs
$933.4K
Avg / prescription
$32.14
Avg / unit
$0.3860
Latest quarter Q4 2025
7.8KRx
Medicaid pays / ea
$0.3860
gross reimbursed
vs
NADAC / ea
$0.3115
acquisition cost
=
Spread
+$0.0745
+24% vs cost
What Medicaid paid per ea (before rebates; includes the pharmacy’s dispensing fee) compared with NADAC — the average price pharmacies pay to buy the drug. A positive spread means Medicaid reimbursed more than the purchase price, before manufacturer rebates.
Fee-for-service vs managed care
89% MCO
Fee-for-service · 3,217 Rx Managed care · 25,820 Rx
State Medicaid map
Alaska: no data reported AK Maine: no data reported ME Washington: no data reported WA Idaho: no data reported ID Montana: no data reported MT North Dakota: no data reported ND Minnesota: no data reported MN Wisconsin: 5,144 units · 87.0 per 100k residents WI Michigan: 708 units · 7.1 per 100k residents MI New York: 30,460 units · 156 per 100k residents NY Vermont: no data reported VT New Hampshire: no data reported NH Oregon: 12,560 units · 297 per 100k residents OR Nevada: no data reported NV Wyoming: no data reported WY South Dakota: no data reported SD Iowa: no data reported IA Illinois: 26,654 units · 212 per 100k residents IL Indiana: 202,676 units · 2,954 per 100k residents IN Ohio: 15,849 units · 134 per 100k residents OH Pennsylvania: 9,280 units · 71.6 per 100k residents PA New Jersey: 5,837 units · 62.8 per 100k residents NJ Massachusetts: 1,918 units · 27.4 per 100k residents MA California: 18,348 units · 47.1 per 100k residents CA Utah: no data reported UT Colorado: no data reported CO Nebraska: 8,024 units · 406 per 100k residents NE Missouri: 5,215 units · 84.2 per 100k residents MO Kentucky: 2,002,651 units · 44,248 per 100k residents KY West Virginia: no data reported WV Virginia: no data reported VA Maryland: 2,221 units · 35.9 per 100k residents MD Connecticut: 3,316 units · 91.7 per 100k residents CT Rhode Island: no data reported RI Arizona: no data reported AZ New Mexico: no data reported NM Kansas: 2,500 units · 85.0 per 100k residents KS Arkansas: no data reported AR Tennessee: 420 units · 5.9 per 100k residents TN North Carolina: 2,917 units · 26.9 per 100k residents NC South Carolina: no data reported SC Delaware: no data reported DE Oklahoma: 7,816 units · 193 per 100k residents OK Louisiana: no data reported LA Mississippi: no data reported MS Alabama: no data reported AL Georgia: no data reported GA D.C.: no data reported DC Hawaii: no data reported HI Texas: 43,518 units · 143 per 100k residents TX Florida: 10,143 units · 44.9 per 100k residents FL
Units reimbursed · per 100k residents
5.944,248
gray = no data reported
Colors are per 100,000 residents, so big states don’t automatically dominate. Tap or hover a state for its actual totals.
Tap or hover a state
…for its Medicaid breakdown
🏆 Top states by units · per 100k residents
1 Kentucky 44,248 /100k
2 Indiana 2,954 /100k
3 Nebraska 406 /100k
4 Oregon 297 /100k
5 Illinois 212 /100k
6 Oklahoma 193 /100k
7 New York 156 /100k
8 Texas 143 /100k
National units — by quarter
💵 About the dollar figures: “reimbursed” is what Medicaid paid pharmacies before confidential manufacturer rebates, so the program’s real net cost is lower than these numbers. Fee-for-service and managed-care claims are combined unless split above. Source: CMS State Drug Utilization Data; per-100k rates use 2023 Census population estimates.

💊 Medicaid utilization by pack size

Medicaid (SDUD) totals over the four most recent reported quarters for every package size of this drug — handy when a specific package (e.g. a starter/titration pack) carries little or no Medicaid volume on its own.
500 tablets this page42543-0497-05 29,037 Rx · $933,371
100 tablets42543-0497-01 14,561 Rx · $467,478
Drug total (last 4 qtrs): 43,598 Rx · 3,290,598 units · $1,400,849 gross reimbursed
Tap a pack size to open its page. Source: CMS State Drug Utilization Data, last 4 quarters.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for AMANTADINE HYDROCHLORIDE — the ingredient across all brands.

Top reported reactions

Fall394
Fatigue312
Gait Disturbance288
Hallucination254
Tremor222
Asthenia213
Depression213

Age at onset

Child2
Adolescent3
Adult195
Elderly128

Reporter sex

4,861 reports
Male · 40%
Female · 60%
Unknown · 0%

Serious outcomes

Hospitalization1,915
Disabling155
Life-threatening151
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 249 0
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startStatus
42543-0497-01 100 TABLET in 1 BOTTLE (42543-497-01) $0.3115 / ea $31.15 2017-08-04 Active
42543-0497-05 You're viewing this 500 TABLET in 1 BOTTLE (42543-497-05) $0.3115 / ea $155.74 2017-08-08 Active

You're viewing the largest of 2 pack sizes for this product.

This pack effectively ties for the lowest per-ea cost of the 2 priced pack sizes ($0.3115 NADAC).

In Medicaid, this is the most-dispensed pack of this product — about 67% of fills over the last four reported quarters. See all packs ↓

Pack size FAQ

What quantity is in NDC 42543-0497-05?
NDC 42543-0497-05 is a 500-count package — 500 tablet in 1 bottle.
What is the difference between NDC 42543-0497-05 and NDC 42543-0497-01?
Both are Amantadine Hydrochloride 100 mg Tablet — the drug itself is identical. NDC 42543-0497-05 is the 500-count package, while NDC 42543-0497-01 is the 100 tablets package.
What NDC number is used to bill for this package of Amantadine Hydrochloride 100 mg Tablet?
Bill NDC 42543-0497-05 — the 11-digit billing format is 42543049705. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage ~2 min read

INDICATIONS AND USAGE Amantadine Hydrochloride Tablets are indicated for the prophylaxis and treatment of signs and symptoms of infection caused by various strains of influenza A virus. Amantadine Hydrochloride Tablets are also indicated in the treatment of parkinsonism and drug-induced extrapyramidal reactions. Influenza A Prophylaxis Amantadine Hydrochloride Tablets are indicated for chemoprophylaxis against signs and symptoms of influenza A virus infection.

Because Amantadine Hydrochloride Tablets do not completely prevent the host immune response to influenza A infection, individuals who take this drug may still develop immune responses to natural disease or vaccination and may be protected when later exposed to antigenically related viruses. Following vaccination during an influenza A outbreak, Amantadine Hydrochloride Tablets prophylaxis should be considered for the 2- to 4-week time period required to develop an antibody response. Influenza A Treatment Amantadine Hydrochloride Tablets are also indicated in the treatment of uncomplicated respiratory tract illness caused by influenza A virus strains especially when administered early in the course of illness.

There are no well-controlled clinical studies demonstrating that treatment with Amantadine Hydrochloride Tablets will avoid the development of influenza A virus pneumonitis or other complications in high risk patients. There is no clinical evidence indicating that Amantadine Hydrochloride Tablets are effective in the prophylaxis or treatment of viral respiratory tract illnesses other than those caused by influenza A virus strains. The following points should be considered before initiating treatment or prophylaxis with Amantadine Hydrochloride Tablets: • Amantadine Hydrochloride Tablets are not a substitute for early vaccination on an annual basis as recommended by the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices. • Influenza viruses change over time.

Emergence of resistance mutations could decrease drug effectiveness. Other factors (for example, changes in viral virulence) might also diminish clinical benefit of antiviral drugs. Prescribers should consider available information on influenza drug susceptibility patterns and treatment effects when deciding whether to use Amantadine Hydrochloride Tablets.

Parkinson's Disease/Syndrome Amantadine Hydrochloride Tablets are indicated in the treatment of idiopathic Parkinson's disease (Paralysis Agitans), postencephalitic parkinsonism, and symptomatic parkinsonism which may follow injury to the nervous system by carbon monoxide intoxication. It is indicated in those elderly patients believed to develop parkinsonism in association with cerebral arteriosclerosis. In the treatment of Parkinson's disease, Amantadine Hydrochloride Tablets are less effective than levodopa, (-)-3-(3,4-dihydroxyphenyl)-L-alanine, and its efficacy in comparison with the anticholinergic antiparkinson drugs has not yet been established.

Drug-Induced Extrapyramidal Reactions Amantadine Hydrochloride Tablets are indicated in the treatment of drug-induced extrapyramidal reactions. Although anticholinergic-type side effects have been noted with Amantadine Hydrochloride Tablets when used in patients with drug-induced extrapyramidal reactions, there is a lower incidence of these side effects than that observed with the anticholinergic antiparkinson drugs.

⏱️ Dosage and Administration ~3 min read

DOSAGE AND ADMINISTRATION The dose of Amantadine Hydrochloride Tablets may need reduction in patients with congestive heart failure, peripheral edema, orthostatic hypotension, or impaired renal function (see Dosage for Impaired Renal Function). Dosage for Prophylaxis and Treatment of Uncomplicated Influenza A Virus Illness Adult The adult daily dosage of Amantadine Hydrochloride Tablets is 200 mg; two 100 mg tablets as a single daily dose. The daily dosage may be split into one tablet of 100 mg twice a day.

If central nervous system effects develop in once-a-day dosage, a split dosage schedule may reduce such complaints. In persons 65 years of age or older, the daily dosage of Amantadine Hydrochloride Tablets is 100 mg. A 100 mg daily dose has also been shown in experimental challenge studies to be effective as prophylaxis in healthy adults who are not at high risk for influenza-related complications.

However, it has not been demonstrated that a 100 mg daily dose is as effective as a 200 mg daily dose for prophylaxis, nor has the 100 mg daily dose been studied in the treatment of acute influenza illness. In recent clinical trials, the incidence of central nervous system (CNS) side effects associated with the 100 mg daily dose was at or near the level of placebo. The 100 mg dose is recommended for persons who have demonstrated intolerance to 200 mg of Amantadine Hydrochloride Tablets daily because of CNS or other toxicities.

Pediatric Patients 1 yr. to 9 yrs. of age The total daily dose should be calculated on the basis of 2 to 4 mg/lb/day (4.4 to 8.8 mg/kg/day), but not to exceed 150 mg per day. 9 yrs. to 12 yrs. of age The total daily dose is 200 mg given as one tablet of 100 mg twice a day. The 100 mg daily dose has not been studied in this pediatric population.

Therefore, there are no data which demonstrate that this dose is as effective as or is safer than the 200 mg daily dose in this patient population. Prophylactic dosing should be started in anticipation of an influenza A outbreak and before or after contact with individuals with influenza A virus respiratory tract illness. Amantadine Hydrochloride Tablets should be continued daily for at least 10 days following a known exposure.

If Amantadine Hydrochloride Tablets are used chemoprophylactically in conjunction with inactivated influenza A virus vaccine until protective antibody responses develop, then it should be administered for 2 to 4 weeks after the vaccine has been given. When inactivated influenza A virus vaccine is unavailable or contraindicated, Amantadine Hydrochloride Tablets should be administered for the duration of known influenza A in the community because of repeated and unknown exposure. Treatment of influenza A virus illness should be started as soon as possible, preferably within 24 to 48 hours after onset of signs and symptoms, and should be continued for 24 to 48 hours after the disappearance of signs and symptoms.

Dosage for Parkinsonism Adult The usual dose of Amantadine Hydrochloride Tablets is 100 mg twice a day when used alone. Amantadine Hydrochloride Tablets have an onset of action usually within 48 hours. The initial dose of Amantadine Hydrochloride Tablets is 100 mg daily for patients with serious associated medical illnesses or who are receiving high doses of other antiparkinson drugs.

After one to several weeks at 100 mg once daily, the dose may be increased to 100 mg twice daily, if necessary. Occasionally, patients whose responses are not optimal with Amantadine Hydrochloride Tablets at 200 mg daily may benefit from an increase up to 400 mg daily in divided doses. However, such patients should be supervised closely by their physicians.

Patients initially deriving benefit from Amantadine Hydrochloride Tablets not uncommonly experience a fall-off of effectiveness after a few months. Benefit may be regained by increasing the dose to 300 mg daily. Alternatively, temporary discontinuation of Amantadine Hydrochloride Tablets for several weeks…

Contraindications 25 words

CONTRAINDICATIONS Amantadine Hydrochloride Tablets are contraindicated in patients with known hypersensitivity to amantadine hydrochloride or to any of the other ingredients in Amantadine Hydrochloride Tablets.

⚠️ Warnings ~2 min read

WARNINGS Deaths Deaths have been reported from overdose with amantadine hydrochloride. The lowest reported acute lethal dose was 1 gram. Acute toxicity may be attributable to the anticholinergic effects of amantadine.

Drug overdose has resulted in cardiac, respiratory, renal or central nervous system toxicity. Cardiac dysfunction includes arrhythmia, tachycardia and hypertension (see OVERDOSAGE ). Deaths due to drug accumulation (overdosage) have been reported in patients with renal impairment, who were prescribed higher than recommended doses of Amantadine Hydrochloride Capsules, USP for their level of renal function (see DOSAGE AND ADMINISTRATION; Dosage of Impaired Renal Function and OVERDOSAGE).

Suicide Attempts Suicide attempts, some of which have been fatal, have been reported in patients treated with amantadine hydrochloride, many of whom received short courses for influenza treatment or prophylaxis. The incidence of suicide attempts is not known and the pathophysiologic mechanism is not understood. Suicide attempts and suicidal ideation have been reported in patients with and without prior history of psychiatric illness.

Amantadine hydrochloride can exacerbate mental problems in patients with a history of psychiatric disorders or substance abuse. Patients who attempt suicide may exhibit abnormal mental states which include disorientation, confusion, depression, personality changes, agitation, aggressive behavior, hallucinations, paranoia, other psychotic reactions, and somnolence or insomnia. Because of the possibility of serious adverse effects, caution should be observed when prescribing Amantadine Hydrochloride Tablets to patients being treated with drugs having CNS effects, or for whom the potential risks outweigh the benefit of treatment.

CNS Effects Patients with a history of epilepsy or other "seizures" should be observed closely for possible increased seizure activity. Patients receiving Amantadine Hydrochloride Tablets who note central nervous system effects or blurring of vision should be cautioned against driving or working in situations where alertness and adequate motor coordination are important. Other Patients with a history of congestive heart failure or peripheral edema should be followed closely as there are patients who developed congestive heart failure while receiving Amantadine Hydrochloride Tablets.

Patients with Parkinson's disease improving on Amantadine Hydrochloride Tablets should resume normal activities gradually and cautiously, consistent with other medical considerations, such as the presence of osteoporosis or phlebothrombosis. Because Amantadine Hydrochloride Tablets have anticholinergic effects and may cause mydriasis, it should not be given to patients with untreated angle closure glaucoma. Corneal Edema Corneal edema has been reported in patients taking amantadine.

Symptoms include sudden onset of blurry vision, or progressive vision loss, with or without eye pain. Corneal involvement is usually bilateral. Onset can occur from a few weeks to several years after starting amantadine.

Resolution of symptoms typically begins within weeks of amantadine cessation. However, corneal grafts have been required in some patients when the condition is not recognized. Permanent damage can occur if amantadine is continued.

Ask patients if their vision has changed and obtain ophthalmologic examinations to rule out corneal edema should vision changes occur after initiation of therapy with amantadine hydrochloride tablets. If corneal edema occurs, taper and discontinue amantadine hydrochloride tablets [see Dosage and Administration] .

🤒 Adverse Reactions ~1 min read

ADVERSE REACTIONS The adverse reactions reported most frequently at the recommended dose of amantadine hydrochloride (5 to 10%) are: nausea, dizziness (lightheadedness), and insomnia. Less frequently (1 to 5%) reported adverse reactions are: depression, anxiety and irritability, hallucinations, confusion, anorexia, dry mouth, constipation, ataxia, livedo reticularis, peripheral edema, orthostatic hypotension, headache, somnolence, nervousness, dream abnormality, agitation, dry nose, diarrhea and fatigue. Infrequently (0.1 to 1%) occurring adverse reactions are: congestive heart failure, psychosis, urinary retention, dyspnea, skin rash, vomiting, weakness, slurred speech, euphoria, thinking abnormality, amnesia, hyperkinesia, hypertension, decreased libido, and visual disturbance, including punctate subepithelial or other corneal opacity, corneal edema, decreased visual acuity, sensitivity to light, and optic nerve palsy.

Rare (less than 0.1%) occurring adverse reactions are: instances of convulsion, leukopenia, neutropenia, eczematoid dermatitis, oculogyric episodes, suicidal attempt, suicide, and suicidal ideation ( see WARNINGS ). Other adverse reactions reported during postmarketing experience with amantadine hydrochloride usage include: Nervous System/Psychiatric - coma, stupor, delirium, hypokinesia, hypertonia, delusions, aggressive behavior, paranoid reaction, manic reaction, involuntary muscle contractions, gait abnormalities, paresthesia, EEG changes, and tremor.

Abrupt discontinuation may also precipitate delirium, agitation, delusions, hallucinations, paranoid reaction, stupor, anxiety, depression and slurred speech; Cardiovascular cardiac arrest, arrhythmias including malignant arrhythmias, hypotension and tachycardia; Respiratory acute respiratory failure, pulmonary edema, and tachypnea; Gastrointestinal dysphagia; Hematologic leukocytosis, agranulocytosis; Special Senses keratitis, mydriasis, and corneal edema; Skin and Appendages pruritus and diaphoresis; Miscellaneous neuroleptic malignant syndrome (see WARNINGS ), allergic reactions including anaphylactic reactions, edema and fever.

Laboratory Test elevated: CPK, BUN, serum creatinine, alkaline phosphatase, LDH, bilirubin, GGT, SGOT, and SGPT. To report SUSPECTED ADVERSE REACTIONS, contact Strides Pharma Inc. at 1-877-244-9825 or go to www.strides.com or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

🆘 Overdosage ~2 min read

OVERDOSAGE Deaths have been reported from overdose with amantadine hydrochloride. The lowest reported acute lethal dose was 1 gram. Because some patients have attempted suicide by overdosing with amantadine, prescriptions should be written for the smallest quantity consistent with good patient management.

Acute toxicity may be attributable to the anticholinergic effects of amantadine. Drug overdose has resulted in cardiac, respiratory, renal or central nervous system toxicity. Cardiac dysfunction includes arrhythmia, tachycardia and hypertension.

Pulmonary edema and respiratory distress (including adult respiratory distress syndrome – ARDS) have been reported; renal dysfunction including increased BUN, decreased creatinine clearance and renal insufficiency can occur. Central nervous system effects that have been reported include insomnia, anxiety, agitation, aggressive behavior, hypertonia, hyperkinesia, ataxia, gait abnormality, tremor, confusion, disorientation, depersonalization, fear, delirium, hallucinations, psychotic reactions, lethargy, somnolence and coma.

Seizures may be exacerbated in patients with prior history of seizure disorders. Hyperthermia has also been observed in cases where a drug overdose has occurred. There is no specific antidote for an overdose of amantadine hydrochloride.

However, slowly administered intravenous physostigmine in 1 and 2 mg doses in an adult 2 at 1- to 2-hour intervals and 0.5 mg doses in a child 3 at 5- to 10-minute intervals up to a maximum of 2 mg/hour have been reported to be effective in the control of central nervous system toxicity caused by amantadine hydrochloride. For acute overdosing, general supportive measures should be employed along with immediate gastric lavage or induction of emesis. Fluids should be forced, and if necessary, given intravenously.

The pH of the urine has been reported to influence the excretion rate of amantadine hydrochloride. Since the excretion rate of amantadine hydrochloride increases rapidly when the urine is acidic, the administration of urine acidifying drugs may increase the elimination of the drug from the body. The blood pressure, pulse, respiration and temperature should be monitored.

The patient should be observed for hyperactivity and convulsions; if required, sedation, and anticonvulsant therapy should be administered. The patient should be observed for the possible development of arrhythmias and hypotension; if required, appropriate antiarrhythmic and antihypotensive therapy should be given. Electrocardiographic monitoring may be required after ingestion, since malignant tachyarrhythmias can appear after overdose.

Care should be exercised when administering adrenergic agents, such as isoproterenol, to patients with an amantadine hydrochloride overdose, since the dopaminergic activity of amantadine hydrochloride has been reported to induce malignant arrhythmias. The blood electrolytes, urine pH and urinary output should be monitored. If there is no record of recent voiding, catheterization should be done.

🧬 Clinical Pharmacology ~3 min read

CLINICAL PHARMACOLOGY Pharmacodynamics Mechanism of Action Antiviral The mechanism by which amantadine exerts its antiviral activity is not clearly understood. It appears to mainly prevent the release of infectious viral nucleic acid into the host cell by interfering with the function of the transmembrane domain of the viral M2 protein. In certain cases, amantadine is also known to prevent virus assembly during virus replication.

It does not appear to interfere with the immunogenicity of inactivated influenza A virus vaccine. Antiviral Activity Amantadine inhibits the replication of influenza A virus isolates from each of the subtypes, i.e., H1N1, H2N2 and H3N2. It has very little or no activity against influenza B virus isolates.

A quantitative relationship between the in vitro susceptibility of influenza A virus to amantadine and the clinical response to therapy has not been established in man. Sensitivity test results, expressed as the concentration of amantadine required to inhibit by 50% the growth of virus (ED 50 ) in tissue culture vary greatly (from 0.1 mcg/mL to 25 mcg/mL) depending upon the assay protocol used, size of virus inoculum, isolates of influenza A virus strains tested, and the cell type used. Host cells in tissue culture readily tolerated amantadine up to a concentration of 100 mcg/mL.

Drug Resistance Influenza A variants with reduced in vitro sensitivity to amantadine have been isolated from epidemic strains in areas where adamantane derivatives are being used. Influenza viruses with reduced in vitro sensitivity have been shown to be transmissible and to cause typical influenza illness. The quantitative relationship between the in vitro sensitivity of influenza A variants to amantadine and the clinical response to therapy has not been established.

Mechanism of Action Parkinson's Disease The mechanism of action of amantadine hydrochloride in the treatment of Parkinson's disease and drug-induced extrapyramidal reactions is not known. Data from earlier animal studies suggest that amantadine hydrochloride may have direct and indirect effects on dopamine neurons. More recent studies have demonstrated that amantadine is a weak, non-competitive NMDA receptor antagonist (Ki = 10μM).

Although amantadine has not been shown to possess direct anticholinergic activity in animal studies, clinically, it exhibits anticholinergic-like side effects such as dry mouth, urinary retention, and constipation. Pharmacokinetics Amantadine Hydrochloride is well absorbed orally. Maximum plasma concentrations are directly related to dose for doses up to 200 mg/day.

Doses above 200 mg/day may result in a greater than proportional increase in maximum plasma concentrations. It is primarily excreted unchanged in the urine by glomerular filtration and tubular secretion. Eight metabolites of amantadine have been identified in human urine.

One metabolite, an N-acetylated compound, was quantified in human urine and accounted for 5 to 15% of the administered dose. Plasma acetylamantadine accounted for up to 80% of the concurrent amantadine plasma concentration in 5 of 12 healthy volunteers following the ingestion of a 200 mg dose of amantadine. Acetylamantadine was not detected in the plasma of the remaining seven volunteers.

The contribution of this metabolite to efficacy or toxicity is not known. There appears to be a relationship between plasma amantadine concentrations and toxicity. As concentration increases, toxicity seems to be more prevalent, however, absolute values of amantadine concentrations associated with adverse effects have not been fully defined.

Amantadine pharmacokinetics were determined in 24 normal adult male volunteers after the oral administration of a single amantadine hydrochloride 100 mg soft gel capsule. The mean ± SD maximum plasma concentration was 0.22 ± 0.03 mcg/mL (range: 0.18 to 0.32 mcg/mL). The time to peak concentration was 3.3 ± 1.5 hours (range 1.5 to 8 hours).

The apparent oral clearance was 0.28 ± 0.11…

📦 How Supplied / Storage and Handling 86 words

HOW SUPPLIED Amantadine Hydrochloride Tablets 100 mg are available as Peach colored, round shaped, flat, beveled edge tablet, debossed as "S" on one side and "502" on other side as follow: NDC 42543-497-01: Bottles of 100 tablets NDC 42543-497-05: Bottles of 500 tablets Store at 20°C to 25°C (68°F to 77°F). Excursions permitted to 15°C to 30°C (59°F to 86°F). [See USP Controlled Room Temperature.] Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure Keep out of reach of children.

📋 Description 98 words

DESCRIPTION Amantadine hydrochloride USP is designated generically as amantadine hydrochloride and chemically as 1-adamantanamine hydrochloride. C 10 H 17 N.HCl Amantadine hydrochloride USP is a white or practically white crystalline powder, freely soluble in water and soluble in alcohol and in chloroform. Amantadine hydrochloride USP has pharmacological actions as both an anti-Parkinson and an antiviral drug.

Each tablet intended for oral administration contains 100 mg amantadine hydrochloride USP and has the following inactive ingredients: microcrystalline cellulose, povidone, sodium starch glycolate (Potato), magnesium stearate, colloidal silicon dioxide, FD&C Yellow No. 6 /Sunset Yellow FCF Al 38% to 42%. amantadine-hcl

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.