Amantadine Hydrochloride 50 mg/5mL Solution, 473 mL
Other active recalls for Amantadine Hydrochloride (different manufacturers) — 1 · tap to view
🆔 Identity & classification
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🏷️ RxNorm drug class
This medicine belongs to the Influenza A M2 Protein Inhibitor class.
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🏭 Manufacturer & labeler
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🩺 Clinical
Amantadine is used to treat the symptoms of Parkinson's disease (PD; a disorder of the nervous system that causes difficulties with movement, muscle control, and balance) and other similar conditions. It is also used to control movement problems that are a side effect of certain medications used to treat Parkinson's disease. Amantadine extended-release capsules (Gocovri®) are used along with the combination of levodopa and carbidopa (Rytary®, Sinemet®) to treat ''off'' episodes (times of difficulty moving, walking, and speaking that may happen when other medications wear off) in people with Pa...
Read the full MedlinePlus article ↗- 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?
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💊 What it looks like
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🧪 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.
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UNII XF417D3PSL
Anhydrous citric acid is a sour, crystalline powder derived from citric acid with water removed. In medicines, it acts as a buffer to control pH, adds tartness to improve taste, and helps tablets disintegrate.
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UNII A2I8C7HI9T
Methylparaben is a preservative derived from benzoic acid that prevents growth of bacteria, fungi, and mold in medicines. It extends the product's shelf life and maintains safety during storage.
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UNII 6DC9Q167V3
Propylene glycol is a clear liquid derived from petroleum or vegetable sources. It acts as a solvent, humectant, and preservative in medicines, helping dissolve active ingredients and maintain product stability.
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UNII Z8IX2SC1OH
Propylparaben is a chemical preservative used to prevent bacterial and fungal growth in medicines and personal care products. It helps extend shelf life and maintain product safety during storage.
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UNII 8KW3E207O2
A liquid sweetener made from sorbitol, a sugar alcohol derived from glucose. It sweetens the medicine and also acts as a humectant to help retain moisture and improve texture in liquid formulations.
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UNII 059QF0KO0R
Water is a liquid solvent that dissolves and mixes ingredients together in liquid medicines, syrups, and injections. It helps distribute the active drug evenly throughout the product.
6 inactive ingredients listed in the exact product block matched to this NDC.
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ingredient 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
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💲 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 system | Per mL | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $0.049 | $23.27 / 473 ml |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $0.0714 | $33.77 / 473 ml |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Amantadine 50 mg/5mL 00116-4010-16 | Xttrium | 473 ml | $0.049 | AA | Availability likely | — |
| Amantadine Hydrochloride 50 mg/5mLthis 62135-0010-47 | Chartwell | 473 ml | $0.049 | AA | Availability likely | — |
| Amantadine Hydrochloride 50 mg/5mL 00121-0646-10 | PAI | 10 cups | — | AA | FDA listed | — |
| Amantadine Hydrochloride 50 mg/5mL 17856-0646-01 | ATLANTIC | 72 cups | — | AA | FDA listed | — |
| Amantadine Hydrochloride 50 mg/5mL 39328-0530-10 | Patrin | 10 cups | — | AA | FDA listed | — |
| Amantadine 50 mg/5mL 50268-0036-14 | AvPAK | 10 cups | — | AA | FDA listed | — |
| Amantadine Hydrochloride 50 mg/5mL 55154-9444-05 | Cardinal | 5 cups | — | AA | FDA listed | — |
| Amantadine Hydrochloride 50 mg/5mL 60687-0797-56 | American | 10 cups | — | AA | FDA listed | — |
| Amantadine Hydrochloride 50 mg/5mL 61037-0484-03 | BAJAJ | 473 ml | — | — | FDA listed | — |
| Amantadine Hydrochloride 100 mg/10mL 62135-0011-24 | Chartwell | 10 cups | — | AA | FDA listed | — |
| Amantadine Hydrochloride 100 mg/10mL 68999-0011-24 | Chartwell | 10 cups | — | AA | FDA listed | — |
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⏳ Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
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🔬 Reported adverse events (FAERS)
Top reported reactions
Age at onset
Reporter sex
Serious outcomes
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📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 62135-0010-47 You're viewing this | 473 mL in 1 BOTTLE (62135-010-47) | 2022-12-13 | Active |
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS AND USAGE Amantadine hydrochloride oral solution is indicated for the prophylaxis and treatment of signs and symptoms of infection caused by various strains of influenza A virus. Amantadine hydrochloride oral solution is also indicated in the treatment of parkinsonism and drug-induced extrapyramidal reactions. Influenza A Prophylaxis Amantadine hydrochloride oral solution is indicated for chemoprophylaxis against signs and symptoms of influenza A virus infection.
Because amantadine hydrochloride oral solution does 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 oral solution prophylaxis should be considered for the 2 to 4 week time period required to develop an antibody response. Influenza A Treatment Amantadine hydrochloride oral solution is 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 oral solution 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 oral solution is 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 oral solution: Amantadine hydrochloride oral solution is 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 oral solution. Parkinson’s Disease/Syndrome Amantadine hydrochloride oral solution is 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 oral solution is 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 oral solution is indicated in the treatment of drug-induced extrapyramidal reactions. Although anticholinergic-type side effects have been noted with amantadine hydrochloride oral solution 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 ▾
DOSAGE AND ADMINISTRATION The dose of amantadine hydrochloride oral solution 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 oral solution is 200 mg (four teaspoonfuls of oral solution) as a single daily dose. The daily dosage may be split into two teaspoonfuls of oral solution 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 oral solution 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 oral solution 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 two teaspoonfuls of oral solution 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 oral solution should be continued daily for at least 10 days following a known exposure.
If amantadine hydrochloride oral solution is 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 oral solution 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 oral solution is 100 mg twice a day when used alone. Amantadine hydrochloride oral solution has an onset of action usually within 48 hours. The initial dose of amantadine hydrochloride oral solution 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 oral solution 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 oral solution not uncommonly experience a fall-off of effectiveness after a few months. Benefit may be regained by increasing the do…
⛔ Contraindications ▾
CONTRAINDICATIONS Amantadine hydrochloride is contraindicated in patients with known hypersensitivity to amantadine hydrochloride or to any of the other ingredients in amantadine hydrochloride.
⚠️ Warnings ▾
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 ). 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 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 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. Patients with Parkinson’s disease improving on amantadine hydrochloride should resume normal activities gradually and cautiously, consistent with other medical considerations, such as the presence of osteoporosis or phlebothrombosis.
Because amantadine hydrochloride has 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.
If corneal edema occurs, taper and discontinue amantadine [see Dosage and Administration ].
🤒 Adverse Reactions ▾
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, fever, pathological gambling, increased libido including hypersexuality, and impulse control symptoms.
Laboratory Test elevated: CPK, BUN, serum creatinine, alkaline phosphatase, LDH, bilirubin, GGT, SGOT, and SGPT.
🔄 Drug Interactions ▾
Drug Interactions Careful observation is required when amantadine hydrochloride is administered concurrently with central nervous system stimulants. Agents with anticholinergic properties may potentiate the anticholinergic-like side effects of amantadine. Coadministration of thioridazine has been reported to worsen the tremor in elderly patients with Parkinson’s disease, however, it is not known if other phenothiazines produce a similar response.
Coadministration of Dyazide (triamterene/hydrochlorothiazide) resulted in a higher plasma amantadine concentration in a 61-year-old man receiving amantadine hydrochloride (Amantadine Hydrochloride, USP) 100 mg TID for Parkinson’s disease. 1 It is not known which of the components of Dyazide contributed to the observation or if related drugs produce a similar response. Coadministration of quinine or quinidine with amantadine was shown to reduce the renal clearance of amantadine by about 30%.
The concurrent use of amantadine hydrochloride with live attenuated influenza vaccine (LAIV) intranasal has not been evaluated. However, because of the potential for interference between these products, LAIV should not be administered within 2 weeks before or 48 hours after administration of amantadine hydrochloride, unless medically indicated. The concern about possible interference arises from the potential for antiviral drugs to inhibit replication of live vaccine virus.
Trivalent inactivated influenza vaccine can be administered at any time relative to use of amantadine hydrochloride. Carcinogenesis and Mutagenesis Long-term in vivo animal studies designed to evaluate the carcinogenic potential of amantadine hydrochloride have not been performed. In several in vitro assays for gene mutation, amantadine hydrochloride did not increase the number of spontaneously observed mutations in four strains of Salmonella typhimurium (Ames Test) or in a mammalian cell line (Chinese Hamster Ovary cells) when incubations were performed either with or without a liver metabolic activation extract.
Further, there was no evidence of chromosome damage observed in an in vitro test using freshly derived and stimulated human peripheral blood lymphocytes (with and without metabolic activation) or in an in vivo mouse bone marrow micronucleus test (140 to 550 mg/kg; estimated human equivalent doses of 11.7 to 45.8 mg/kg based on body surface area conversion). Impairment of Fertility The effect of amantadine on fertility has not been adequately tested, that is, in a study conducted under Good Laboratory Practice (GLP) and according to current recommended methodology.
In a three litter, non-GLP, reproduction study in rats, amantadine hydrochloride at a dose of 32 mg/kg/day (equal to the maximum recommended human dose on a mg/m 2 basis) administered to both males and females slightly impaired fertility. There were no effects on fertility at a dose level of 10 mg/kg/day (or 0.3 times the maximum recommended human dose on a mg/m 2 basis); intermediate doses were not tested. Failed fertility has been reported during human in vitro fertilization (IVF) when the sperm donor ingested amantadine 2 weeks prior to, and during the IVF cycle.
Pregnancy The effect of amantadine on embryofetal and peri-postnatal development has not been adequately tested, that is, in studies conducted under Good Laboratory Practice (GLP) and according to current recommended methodology. However, in two non-GLP studies in rats in which females were dosed from 5 days prior to mating to Day 6 of gestation or on Days 7 to 14 of gestation, Symmetrel produced increases in embryonic death at an oral dose of 100 mg/kg (or 3 times the maximum recommended human dose on a mg/m 2 basis).
In the non-GLP rat study in which females were dosed on Days 7 to 14 of gestation, there was a marked increase in severe visceral and skeletal malformations at oral doses of 50 and 100 mg/kg (or 1.5 and 3 times, respectively, the maximum recommended human dose on a mg/m 2 basis). Th…
🆘 Overdosage ▾
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 a 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 ▾
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 µg/mL to 25.0 µg/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 µg/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 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 (K i = 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 µg/mL (range: 0.18 to 0.32 µg/mL). The time to peak concentration was 3.3 ± 1.5 hours (range: 1.5 to 8.0 hours).
The apparent oral clearance was 0.28 ±
0.11 L/hr/kg (r…
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED Amantadine Hydrochloride Oral Solution, USP 50 mg/5 mL is available as clear solution with cherry flavor [each 5 mL (1 teaspoonful) contains 50 mg amantadine hydrochloride] in: 16 oz. ( 473 mL) bottles NDC 62135-010-47 10 mL Unit Dose Cup NDC 62135-011-59 20 Unit Dose Cups of 10 mL each NDC 62135-011-24 Store at controlled room temperature 20° to 25°C (68° to 77°F) [see USP]. Dispense in a tight container as defined in the USP, with a child-resistant closure (as required).
REFERENCES 1 W.W. Wilson and A.H. Rajput, Amantadine-Dyazide Interaction, Can.
Med. Assoc. J.
129:974-975, 1983. 2 D.F. Casey, N.
Engl. J. Med.
298:516, 1978. 3 C.D. Berkowitz, J.
Pediatr. 95:144, 1979. Manufactured for: Chartwell RX, LLC Congers, NY 10920 L71163 Rev.
12/2025
📋 Description ▾
Amantadine Hydrochloride Oral Solution, USP Rx only DESCRIPTION Amantadine Hydrochloride Oral Solution, USP is designated generically as amantadine hydrochloride and chemically as 1-adamantanamine hydrochloride. Amantadine hydrochloride is a stable white or nearly white crystalline powder, freely soluble in water and soluble in alcohol and in chloroform. Amantadine hydrochloride has pharmacological actions as both an anti-Parkinson and an antiviral drug.
Amantadine Hydrochloride Oral Solution, USP is available in oral solution. Amantadine Hydrochloride Oral Solution, USP contains 50 mg of amantadine hydrochloride per 5 mL and has the following inactive ingredients: sorbitol solution, anhydrous citric acid, methylparaben, propylparaben, propylene glycol, purified water, and wild cherry flavor. image description
💬 Information for Patients ▾
Information for Patients Patients should be advised of the following information: Blurry vision, eye pain, loss of vision, and/or impaired mental acuity may occur. Gradually increase physical activity as the symptoms of Parkinson’s disease improve. Avoid excessive alcohol usage, since it may increase the potential for CNS effects such as dizziness, confusion, lightheadedness and orthostatic hypotension.
Avoid getting up suddenly from a sitting or lying position. If dizziness or lightheadedness occurs, notify physician. Notify physician if mood/mental changes, swelling of extremities, difficulty urinating and/or shortness of breath occur.
Do not take more medication than prescribed because of the risk of overdose. If there is no improvement in a few days, or if medication appears less effective after a few weeks, discuss with a physician. Consult physician before discontinuing medication.
Seek medical attention immediately if it is suspected that an overdose of medication has been taken. There have been reports of patients experiencing intense urges to gamble, increased sexual urges, and other intense urges, and the inability to control these urges while taking one or more of the medications that increase central dopaminergic tone and that are generally used for the treatment of Parkinson’s disease, including amantadine hydrochloride. Although it is not proven that the medications caused these events, these urges were reported to have stopped in some cases when the dose was reduced or the medication was stopped.
Prescribers should ask patients about the development of new or increased gambling urges, sexual urges or other urges while being treated with amantadine hydrochloride. Patients should inform their physician if they experience new or increased gambling urges, increased sexual urges or other intense urges while taking amantadine hydrochloride. Physicians should consider dose reduction or stopping the medication if a patient develops such urges while taking amantadine hydrochloride.