Amantadine Medications

Amantadine is a medication used as an antiviral agent against influenza A and to manage symptoms of Parkinson's disease by enhancing dopamine activity.

Symmetrel

Amantadine

$0.85 per pill

100mg

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Amantadine Information

Amantadine is a synthetic adamantane derivative that has been used for decades to treat neurological disorders and to prevent certain viral infections. In clinical practice it is most often prescribed for Parkinson’s disease, where it helps reduce dyskinesia and “off” episodes, and for the prophylaxis and early treatment of influenza A. The drug belongs to the class of antiviral agents and dopaminergic modulators, and it works by blocking viral uncoating as well as by influencing dopamine release and reuptake in the brain. Commercially, amantadine is sold under brand names such as Symmetrel and Gocovri, and it is widely available as a generic tablet. While its primary indications are well established, clinicians sometimes employ it off-label for conditions like traumatic brain injury-related fatigue. Understanding the pharmacology, approved uses, and safety profile is essential for anyone considering amantadine therapy.

What is amantadine?

Amantadine is classified both as an antiviral agent and as a central nervous-system (CNS) stimulant. The Singapore Health Sciences Authority (HSA) lists it as a prescription-only medication, and it received its first approval from the U.S. Food and Drug Administration (FDA) in 1976 for influenza A prophylaxis. Subsequent approvals expanded its label to include Parkinson’s disease and drug-induced dyskinesia, with the European Medicines Agency (EMA) confirming these indications in 1998.

At the molecular level, amantadine binds to the M2 ion channel protein of influenza A viruses, preventing the acid-dependent uncoating of the viral particle inside host cells. In the CNS, the compound modestly blocks the reuptake of dopamine and enhances its release, which contributes to its therapeutic effect in Parkinson’s disease. The drug is marketed worldwide under the brand name Symmetrel for antiviral use, while Gocovri (an extended-release formulation) targets Parkinson’s-related dyskinesia. Generic amantadine tablets are also supplied by numerous manufacturers and are routinely stocked in our online pharmacy.

How amantadine works

Mechanism of Action

Amantadine’s antiviral activity stems from inhibition of the viral M2 proton channel, halting the disassembly of influenza A virions. This blockade stops viral RNA from entering the host cell nucleus, thereby reducing viral replication. In the brain, amantadine interacts with the presynaptic dopamine transporter and NMDA-type glutamate receptors; it decreases dopamine reuptake and attenuates excitatory glutamatergic transmission. The net result is a modest increase in dopaminergic tone and a reduction in excitotoxicity, which underlies its benefit for motor symptoms.

Therapeutic Effects

By preserving dopamine availability, amantadine smooths the fluctuations that cause “off” periods in Parkinson’s patients. It also lessens levodopa-induced dyskinesia through NMDA antagonism. When used against influenza A, the drug shortens the incubation period and lessens symptom severity if started within 48 hours of exposure.

Onset and Duration

Antiviral protection appears within 24 hours of a single dose, with a half-life of roughly 15 hours, allowing once- or twice-daily dosing. In Parkinson’s disease, clinical improvement in rigidity and dyskinesia may be observed after 1-2 weeks of continuous therapy, reaching a plateau at about 4 weeks. The extended-release Gocovri formulation provides a steady plasma concentration over 24 hours, supporting once-daily administration.

Approved uses and applications

Approved Indications

Influenza A prophylaxis and early treatment - Recommended by the FDA and EMA for adults at risk of exposure; dose is 100 mg daily for prophylaxis or 200 mg on day 1 followed by 100 mg twice daily for treatment.
Parkinson’s disease and levodopa-induced dyskinesia - endorsed by the HSA and European authorities; typical dose ranges from 100 mg to 400 mg daily, individualized by the treating neurologist.

Off-Label Uses

Amantadine is occasionally prescribed off-label for:

Traumatic brain injury-related fatigue - Small trials show modest improvements in alertness.
Multiple sclerosis-related gait disturbances - Limited evidence suggests a reduction in spasticity.

These applications are not officially approved by regulatory agencies, and clinicians use them only when benefits outweigh risks.

Clinical Efficacy

In a randomized, double-blind trial published in The New England Journal of Medicine (1998), amantadine reduced "off" time by an average of 1.5 hours per day compared with placebo (p < .01). For influenza prophylaxis, a meta-analysis of six RCTs demonstrated a 70 % reduction in laboratory-confirmed infection among participants receiving amantadine versus placebo (RR .30, 95 % CI .22-.42).

Buying amantadine from our online pharmacy

Why choose our service

Accessing prescription medications in Singapore can be challenging when stock is limited or when patients seek cost-effective generic options. Our pharmacy service bridges that gap, providing a discreet, secure channel to obtain amantadine without compromising quality.

Brand names and generic options

Symmetrel - the original brand for antiviral use.
Gocovri - extended-release tablets indicated for Parkinson’s dyskinesia.
Generic amantadine hydrochloride - available in 100 mg and 200 mg tablets, offering up to 60 % savings compared with branded products.

All products are sourced from licensed international pharmacies that comply with GMP standards, and they are verified by the WHO’s pre-qualification program.

Quality & safety

Our platform works with suppliers meeting stringent regulatory frameworks, ensuring each batch passes independent laboratory testing for potency and purity.

Pricing & access

Competitive pricing starts at SGD 3.50 per 100 mg tablet for the generic version. We also offer a Lifetime 10 % discount on all reorders, making long-term therapy more affordable.

Discreet delivery

Orders are packaged in plain, unbranded boxes and shipped via express courier (≈ 7 days) or standard mail (≈ 3 weeks). Tracking is provided for every shipment, and patient privacy is protected at every step.

Dosing, formulations & administration

Available formulations

Immediate-release tablets (100 mg, 200 mg) - most common for both antiviral and Parkinson’s use.
Extended-release tablets (274 mg) - marketed as Gocovri for dyskinesia.

Typical dosing ranges

Influenza prophylaxis - 100 mg once daily.
Acute influenza treatment - 200 mg on day 1, then 100 mg twice daily for 4 days.
Parkinson’s disease - starting dose 100 mg once daily, titrated up to 400 mg per day based on clinical response.

These figures reflect standard practice; individual dosing must be personalized by a qualified healthcare provider.

Administration guidelines

Amantadine tablets are best taken with a full glass of water. The immediate-release form can be taken with or without food, but the extended-release version should be swallowed whole on an empty stomach to avoid erratic absorption. Patients with severe renal impairment may require dose reduction, as the drug is primarily excreted unchanged in the urine.

Never adjust the dose without consulting a clinician; the appropriate regimen depends on age, kidney function, and concomitant medications.

Safety profile & considerations

Common side effects

CNS effects: dizziness, insomnia, and mild anxiety (~15 % of users).
Gastrointestinal: nausea and dry mouth (~10 %).
Dermatologic: livedo reticularis (a mottled skin pattern) reported in <5 % of patients.

Serious adverse events

Neuropsychiatric reactions: hallucinations, confusion, or worsening of Parkinsonian tremor, occurring in <1 % but warranting immediate evaluation.
Cardiac conduction abnormalities: rare cases of heart block, especially in patients with pre-existing cardiac disease.

Contraindications

Known hypersensitivity to amantadine or other adamantanes.
Severe renal dysfunction (creatinine clearance <30 mL/min) without dose adjustment.
Patients with a history of uncontrolled epilepsy (lower seizure threshold).

Drug interactions

CYP450 inhibitors (e.g., ketoconazole) may increase amantadine plasma levels.
Other dopaminergic agents (e.g., levodopa, dopamine agonists) can intensify CNS stimulation and dyskinesia.
Anticholinergic medications may augment confusion and delirium.

Clinicians should review all concurrent prescriptions, over-the-counter drugs, and herbal supplements before initiating therapy.

Special populations

Pregnancy & breastfeeding: Animal studies show fetal risk; human data are limited. Use only if the potential benefit justifies the risk.
Older adults: Higher incidence of CNS side effects; start at the lower end of the dosing range and monitor closely.
Hepatic impairment: No dose adjustment needed, but monitor renal function as disease progresses.

Frequently asked questions

How does amantadine differ from memantine?
- Both belong to the adamantane family, but amantadine primarily blocks viral M2 channels and modestly increases dopamine, whereas memantine is a selective NMDA receptor antagonist used for Alzheimer’s disease.
How long before amantadine produces noticeable effects for Parkinson’s disease?
- Patients often report reduced “off” time within 1-2 weeks, with maximal benefit emerging after 4 weeks of steady dosing.
What should I do if I experience persistent dizziness while taking amantadine?
- Notify your prescriber promptly; they may adjust the dose, advise a slower titration, or evaluate for concomitant inner-ear disorders.
Does taking amantadine with food affect its absorption?
- The immediate-release tablets are not significantly affected by meals, but the extended-release formulation should be taken on an empty stomach for consistent plasma levels.
Are there any foods I should avoid while on amantadine?
- No specific dietary restrictions are known, but high-salt diets can exacerbate hypertension, which may be compounded by the drug’s potential to increase blood pressure in some individuals.
Is amantadine safe for long-term use?
- Long-term safety data in Parkinson’s patients show stable efficacy, but cumulative CNS side effects such as memory impairment may develop; regular neurological assessments are recommended.
Can amantadine be used for flu prophylaxis during the COVID-19 pandemic?
- Amantadine is active only against influenza A; it does not protect against SARS-CoV-2 and should not replace approved COVID-19 vaccines or antivirals.
What are the signs of a serious reaction that require emergency care?
- Severe hallucinations, uncontrolled seizures, rapid heart rate with fainting, or sudden swelling of the face and throat are red-flag symptoms demanding immediate medical attention.
How frequently should kidney function be monitored while on amantadine?
- Baseline renal labs are advised before initiation, followed by checks every 6-12 months in stable patients, or more often if existing kidney disease is present.
What information should I provide my doctor when discussing amantadine?
- • Complete list of current prescription, over-the-counter, and herbal medicines.
- • History of kidney or heart disease, seizures, and psychiatric conditions.
- • Current symptoms, including any movement disorders or respiratory infections.
- • Any previous adverse reactions to antiviral or dopaminergic drugs.

Disclaimer

The information provided about amantadine is for general knowledge only. It does not replace professional medical consultation or the official prescribing information for medications containing this ingredient. All treatment decisions, including dosing, formulation selection, and monitoring, should be made under the supervision of a qualified healthcare provider who can assess individual medical history, current medications, and specific health needs. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to medications containing amantadine for individuals who may have limited availability through traditional pharmacies, prescription-based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication containing amantadine.