Anasin

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Anasin

What is Anasin? (Amantadine Hydrochloride)

Property Description
Active ingredient Amantadine Hydrochloride
Form Tablets and capsules (oral)
Pharmacological class Antiviral agent and Dopaminergic agent
General purpose Modulation of nerve signals and interference with viral processes
Origin Synthetic compound

What Type of Medicine is Anasin?

Anasin is a synthetic prescription medication whose singular active component is Amantadine Hydrochloride. This compound is formally recognized as belonging to two distinct pharmacological categories: it functions as an Antiviral agent and is concurrently classified as a Dopaminergic agent. This dual classification is a unique attribute defining the medicine's identity. The active substance, Amantadine, is a tricyclic amine derivative and is structurally identified as an Adamantane derivative due to its unique chemical structure. The compound is synthesized for systemic delivery, differentiating it from topically applied products and allowing it to influence brain chemistry and viral replication.

Composition, Form, and General Purpose

The formulation of Anasin is a single-entity product, consisting solely of the active substance, Amantadine Hydrochloride, combined with inert pharmaceutical excipients necessary for preparation. It is typically supplied for oral administration in solid dosage forms, specifically as tablets and capsules. The general purpose of this medicine is related to its capacity to address two distinct physiological requirements. As a dopaminergic agent, its function involves the ability to potentiate dopamine release in the brain. In this capacity, it helps to stabilize neurochemical balance by influencing key nerve signals in the central nervous system. Separately, as an antiviral agent, its properties are employed to interfere with the replication process of certain viruses, contributing to the body’s defense against specific infections.

What side effects are possible with Anasin?

Possible Side Effects and Safety Information

The safety profile of Anasin (Amantadine Hydrochloride) is officially documented and categorized by regulatory bodies based on the frequency and the organ systems potentially affected. The manifestation of possible adverse reactions is often transient and typically occurs within the first few days of starting treatment.

Frequency-Classified Adverse Reactions

Adverse reactions documented as Very Common (may affect more than 1 in 10 people) include peripheral oedema (swelling) and the skin condition livedo reticularis. Reactions classified as Common (may affect up to 1 in 10 people) often involve the Nervous System (e.g., dizziness, insomnia, confusion) and the Gastrointestinal System (e.g., dry mouth, nausea, constipation).

Clinically Significant Safety Patterns

The official labeling highlights the potential for serious adverse reactions, including seizure, psychotic disorder, and suicidal ideation or attempt. A symptom complex resembling Neuroleptic Malignant Syndrome (NMS) has been reported following the abrupt discontinuation or rapid dose reduction of the medicine. Furthermore, the label notes the risk of impulse control disorders, such as pathological gambling, associated with dopaminergic agents like Amantadine.

Population and Duration-Related Safety

Certain safety considerations are specific to patient groups. Older adults and individuals with renal impairment require caution, as higher plasma concentrations and associated central nervous system effects are more likely in these populations. Monitoring for effects like orthostatic hypotension is advised at treatment initiation and following dose increases. The medication is generally restricted for use during pregnancy and breastfeeding.

Overdose and Emergency Response

Overdose and when to seek help

Overdose of Anasin (Amantadine Hydrochloride) is associated with severe, documented effects on the central nervous system (CNS) and the cardiovascular system, with reported outcomes that can be life-threatening.

Documented Overdose Presentations:

  • CNS Manifestations: Confusion, agitation, disorientation, visual or auditory hallucinations, delirium, acute psychosis, slurred speech, myoclonus, tremor, and seizures are among the clinical signs documented in official labeling.
  • Cardiovascular Effects: Manifestations include fast or irregular heartbeats (arrhythmias, sinus tachycardia), hypertension, QTc interval prolongation, QRS widening, and the risk of ventricular arrhythmias, including Torsade de pointes.
  • Other Severe Signs: Difficulty breathing, decreased urination (potentially leading to acute renal failure), and peripheral edema are also noted in the overdose context.

Emergency Actions and Help-Seeking:

  • No specific antidote is known for Anasin overdose; management is strictly symptomatic and supportive treatment, including continuous monitoring of the patient.
  • Immediate medical attention is required for an overdose. You must call emergency services immediately if the victim has collapsed, had a seizure, has trouble breathing, or cannot be awakened.
  • Increased severity and risk of death are documented in individuals with renal impairment, as amantadine is primarily eliminated by the kidneys.

Therapeutic Uses of Anasin

What Anasin Treats: Main Uses and Benefits

Anasin (Amantadine Hydrochloride) is applied in contexts where additional symptomatic support is needed to address two distinct, challenging symptom domains: symptoms related to increased neurological or muscular activity and symptoms associated with acute or episodic changes. These applications define the medication's core therapeutic domains.

Motor Symptom Management

The medication is commonly used across conditions involving episodic or fluctuating manifestations, including Parkinsonism and drug-induced extrapyramidal reactions. Anasin is relevant for managing symptom clusters that interfere with daily comfort. It is commonly used to help manage the slowness of movement (bradykinesia), muscle stiffness (rigidity), uncontrolled, excessive motions (dyskinesia), and sudden periods of decreased mobility (motor 'off' episodes). This medication generally provides support that helps ease the overall symptom burden of these difficult episodes, supporting maintaining a sense of stability when symptoms are more noticeable.

Support for Acute Illness

In a separate context, Anasin is applied in clinical settings that involve acute or unstable symptom patterns related to the specific Influenza A virus infection, both for treatment and prevention. It is used to help address the systemic symptoms, providing temporary functional support that assists in easing the impact of the viral symptoms on routine activities.


Therapeutic Focus: Managing Slowness of Movement (Bradykinesia)

Anasin is generally used to help manage the slowness of movement and muscle stiffness associated with Parkinson's disease, and may assist with maintaining functional stability during symptomatic periods.

Eligibility and Restrictions for Use

Official Eligibility and Non-Eligibility for Anasin

Regulatory documents define who is eligible to use Anasin (Amantadine Hydrochloride) and who is absolutely prohibited. Eligibility is primarily established for adults for approved indications. Use for Influenza A treatment and prophylaxis is also established for children and adolescents 10 years of age. Safety and efficacy are not established in infants below one year of age.


Classification Population/Condition Constraint Basis (Regulatory)
Contraindicated End-Stage Renal Disease (ESRD) CrCl below 15 mL/ min/1.73 m^2
Hypersensitivity Known allergy to Amantadine or components
Pregnancy Use is either contraindicated or safety is not established
Untreated narrow-angle glaucoma Risk of exacerbation
Restricted Use Renal Impairment (Non-ESRD) Requires dose adjustment due to decreased drug clearance
Hepatic Impairment Use requires caution and monitoring
Older Adults (65 years) Caution advised due to generally lower renal clearance
History of Seizures/Epilepsy Requires close observation
Not Recommended Nursing Mothers Excreted into breast milk; not recommended during lactation

Regulatory documentation also specifies that women of childbearing potential must use effective contraception during treatment. Patients with a major psychotic disorder should ordinarily not be treated with the medicine. These population restrictions are explicitly defined by regulatory agencies to minimize risk to non-eligible groups and ensure use is confined to officially established populations.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory documentation identifies several key domains of interaction for Anasin, primarily driven by its active components, aspirin and caffeine. Co-administration with certain medicinal products and substances requires specific precautions or avoidance.

Documented Interacting Medicines and Substances

Category Specific Examples or Restrictions
Anticoagulants/Blood Thinners Warfarin, Enoxaparin, Dabigatran. Monitoring of blood clotting time (e.g., INR) is required due to increased bleeding risk.
Other NSAIDs Ibuprofen, Naproxen, Ketorolac. Avoid combination due to increased risk of gastrointestinal (GI) bleeding and ulceration.
Specific Medications Methotrexate, Probenecid, Cimetidine, Theophylline. Co-administration may alter drug levels or increase the risk of adverse effects.
Alcohol Avoid entirely due to a significantly increased risk of GI bleeding.
Tobacco/Smoking May increase the clearance of the caffeine component, potentially reducing the overall effectiveness of the product.

Official labeling contains specific timing rules for patients taking this product for cardiovascular prevention: Ibuprofen must be taken at least 8 hours before or 30 minutes after Anasin (non-enteric coated) to ensure the full antiplatelet effect is retained. Combinations with Cidofovir, Defibrotide, and Ketorolac are strictly contraindicated in regulatory documents. These constraints ensure the safe and effective use of the product by managing the risk of pharmacodynamic and pharmacokinetic interactions.

Mechanism of Action

Enzyme-Mediated Signaling Modulation

The primary mechanism involves the non-selective inhibition of cyclooxygenase (COX) enzymes (COX-1 and COX-2). The Aspirin component achieves this by acting as an irreversible acetylating agent. By suppressing the activity of these enzymes, Aspirin inhibits the key signaling sequences that lead to the biosynthesis of prostaglandins and thromboxanes. Modification of these initial molecular steps in the eicosanoid cascade results in the reduction of pro-inflammatory mediator biosynthesis, leading to altered pathway activity.


Central Nervous System and Pathway Augmentation

The secondary mechanism involves the component Caffeine, which acts as a pharmacological adjuvant to the enzyme-inhibiting component. Caffeine functions as a central nervous system stimulant and may also influence the absorption rate of the Aspirin component in the gastrointestinal tract. Furthermore, it engages mechanisms that regulate specific circulatory patterns, leading to vasoconstriction in certain vascular beds. The combination of these distinct actions contributes to a combined pharmacological profile involving altered local and systemic signaling.

Dosage and Administration Information

How Anasin is Used: Administration Guidelines

Anasin (Amantadine Hydrochloride) is indicated for oral administration in both immediate-release (IR) and extended-release (ER) forms. The medicine is typically taken with or without food; however, all ER products, including tablets and capsules, must be swallowed whole and must not be crushed, chewed, or divided.

The administration schedule is dependent upon the specific formulation and indication. Immediate-release dosing generally starts at 100 mg once daily, progressing to a usual maintenance dose of 100 mg twice daily (200 mg/day). Dosing for extended-release forms requires a gradual titration schedule, where the amount is increased in weekly intervals to the established maintenance level. Use for acute conditions, such as Influenza A, must continue for 24 to 48 hours after symptoms have resolved.

Standard guidelines include specific dose adjustments for certain patient populations. For older adults, a reduced starting dose is often applied, and for all patients, a significant dose reduction or extended dosing interval is required when renal function is impaired. This adjustment is calculated based on creatinine clearance. Discontinuation of Anasin after long-term use must be done through a required gradual dose taper to prevent symptom re-emergence.

Recent Clinical Evidence

Research evidence / Overview of studies for Anasin

Studies help show what has been observed so far regarding the compounds and research on Anasin for its studied applications. Research in this area included trials that assessed how symptoms change over time. The findings describe group patterns and provide context, but not individual predictions, for conditions characterized by fluctuating or episodic manifestations.


Evidence for Use in Managing Involuntary Movements (Dyskinesia)

Clinical research for managing involuntary movements was studied for conditions marked by functional limitations. The primary focus of the research was on outcomes reflecting daily functioning or activity level and outcomes related to physical discomfort.

Studies explored whether measured changes in these outcomes related to overall body function were observed in participants receiving Anasin. The findings describe patterns observed in the studies, focusing specifically on how patient-reported outcomes describing perceived discomfort were monitored in the observed populations.

Follow-up durations were limited in many of the core studies. Therefore, long-term effects are not fully established. Comparative evidence is lacking against a full range of other currently available therapeutic approaches, meaning certainty remains low in some comparisons.


Evidence for Use in Managing Core Motor Symptoms (Rigidity and Slowness of Movement)

Research for Anasin's role in addressing fundamental symptoms like rigidity and slowness of movement was evaluated in studies focusing on outcomes capturing phases of heightened symptom activity.

Data show patterns related to outcomes describing episodic or acute changes that were observed in some studies comparing Anasin to control groups. Research focusing on this area has findings that were mixed across some trials.


Evidence for Use Against the Influenza A Virus

Research that examined use against the Influenza A virus was applied in studies examining patient-reported experiences for conditions associated with acute or disruptive episodes. These studies monitored outcomes related to the overall duration of symptomatic illness in the observed populations.

Research indicates that viral resistance to this class of medication was observed in some studies, which means the applicability of historical findings to currently circulating viral strains may be significantly limited.


Research Gaps and Areas of Uncertainty

Evidence quality varies across studies. Research does not determine whether an individual will respond similarly, as findings describe group patterns, not personal outcomes. This synthesis highlights what is known — and what is still uncertain in the evidence landscape.

Key Studies & References

  1. NICE Guideline NG71: Parkinson's disease in adults

Frequently Asked Questions (FAQ)

Common questions about Anasin (FAQ)


Q: Is Anasin considered a pain reliever, or does it work differently?

Official product information classifies the active ingredient, Amantadine, as an antiviral and an agent used for conditions like Parkinson's disease. Its mechanism of action works on nerve signals through the dopaminergic system and NMDA receptors. It is not officially classified as an analgesic or pain reliever.


Q: Can Anasin be taken by people who are sensitive to NSAIDs?

The active ingredient, Amantadine, is not classified as a nonsteroidal anti-inflammatory drug (NSAID). Its primary mechanism of action involves different pathways, focusing on nerve signals rather than cyclooxygenase (COX) enzyme inhibition.


Q: Why do some people say Anasin makes them feel tired?

Regulatory documents list fatigue, drowsiness, and dizziness as commonly reported side effects. Some patients have reported feeling like they might fall asleep while engaging in daily activities. This is noted in the adverse reaction information for the medication.


Q: Is it possible to become reliant on Anasin if I use it frequently?

Regulatory documents note that abrupt discontinuation of the active ingredient should be avoided because it can lead to serious withdrawal-like symptoms, including a syndrome resembling Neuroleptic Malignant Syndrome (NMS). For this reason, official product information specifies that discontinuation should occur through a gradual dose taper.


Q: What is the official classification of Anasin (e.g., controlled substance, prescription only)?

According to official regulatory status, Anasin is a prescription-only medication. It is generally classified as a non-controlled substance in the United States.


Q: What is the difference between taking Anasin with or without food?

Official administration advice states that extended-release dosage forms of the active ingredient can be taken either with or without food. The full regulatory labeling does not specify a functional difference between these two conditions.


Q: What is the most serious side effect reported for Anasin, according to official sources?

Official regulatory documents list several serious potential adverse reactions. These include falling asleep suddenly during routine daily activities, hallucinations, suicidal thoughts or actions, and a Neuroleptic Malignant Syndrome (NMS)-like reaction if the medication is stopped abruptly.


Q: Is Anasin available over the counter in any countries?

Regulatory authorities in major Western jurisdictions classify the active ingredient, Amantadine, as a prescription-only medicine. The official status in these jurisdictions is that of a prescription-only medicine.


Q: What are the potential descriptive effects of Anasin on mood or focus?

Regulatory adverse reaction information indicates the medication can affect the central nervous system. Reported effects include confusion, agitation, paranoia, hallucinations, and anxiety. Suicidal thoughts and trouble concentrating have also been reported.


Q: How quickly does the effect of Anasin usually start?

The regulatory information regarding pharmacokinetics indicates how quickly the drug enters the bloodstream. The time to reach peak concentration ( Tmax) for the active ingredient typically averages about two to four hours after administration.


Q: Does Anasin stay in the system for a long time after taking it?

Official pharmacokinetic data indicates the elimination half-life of the active ingredient averages approximately 16 hours in healthy adults. This half-life is the time it takes for the drug concentration in the body to be reduced by half. The half-life may be longer for older adults or those with impaired kidney function.


Q: Does Anasin interact with common herbal supplements like St. John's Wort?

Drug interaction references indicate that combining the active ingredient with St. John's Wort can increase the risk or severity of a condition called Serotonin Syndrome.


Q: Are there any known interactions between Anasin and common allergy medicines?

Amantadine has anticholinergic effects, meaning it can affect certain nerve signals. Official regulatory warnings note that using it with other medicines that also have anticholinergic properties, such as specific common allergy medicines, may increase the severity of side effects like confusion or dry mouth.


Q: Are there any known side effects that occur only after long-term use of Anasin?

Official product information describes two side effects associated with chronic treatment. These are peripheral edema (swelling, often of the lower legs or feet) and Livedo Reticularis (a purplish, net-like skin pattern), which may not be seen until after four weeks of use.


Q: What should I do if I suspect an unusual or severe reaction to Anasin?

Official patient information indicates that if a person experiences serious symptoms, such as hallucinations, thoughts of self-harm, or significant swelling, seeking immediate medical attention is necessary.


Q: Can Anasin be used by individuals who are taking blood pressure medication?

The active ingredient may cause orthostatic hypotension (a drop in blood pressure when standing up). Official drug interaction information notes that combining it with other blood pressure-lowering medications, such as thiazide diuretics, may have additive effects in lowering blood pressure.


Q: Are there any official recommendations regarding driving or operating machinery while using Anasin?

Official regulatory warnings indicate caution is necessary for activities requiring full alertness. Due to the risk of side effects like drowsiness, dizziness, and blurred vision, patients should be aware of how the medication affects them before driving or operating machinery.


Q: Can Anasin impact lab test results, such as blood tests?

Official adverse reaction information indicates the medication can affect laboratory test results. Specifically, it can inhibit a kidney transport mechanism, which may result in an increase in serum creatinine concentrations and lead to a false impression of mild kidney impairment.


Q: Can Anasin be used by people with specific dietary restrictions (e.g., gluten-free, vegetarian)?

The product's official labeling sometimes lists excipients with known effects, such as lactose. The official patient information leaflet contains the full list of inactive ingredients, which is the necessary source for checking for known dietary or allergen restrictions.


Q: What is the expected duration of the beneficial effects after a single use of Anasin?

Regulatory documents provide the elimination half-life of the active ingredient, which is a measure of how long it stays in the body. The half-life is approximately 17 hours in healthy adults.


Q: Does Anasin interact with common pain creams or topical medications?

Regulatory guidance suggests that topical medicines generally have limited absorption into the body. Therefore, those that are not significantly absorbed are not likely to cause clinically meaningful interactions with the active ingredient.


Q: What is the physical appearance of the Anasin tablet or capsule?

The official labeling for the active ingredient describes the physical appearance of its dosage forms. For example, some formulations are described as brownish-red capsules or peach, round tablets with specific imprints.


Q: Are there specific patient education materials required by regulatory bodies for Anasin?

For prescription products containing the active ingredient, the FDA generally requires that a Medication Guide be provided to the patient. This guide is required due to the risks associated with the drug that need careful patient consideration.

How should Anasin be stored and disposed of?

The official regulatory requirements for the storage and disposal of Anasin are designed to maintain product quality and ensure safety.

Storage Requirements

Classification Official Regulatory Statement
Temperature Store at Controlled Room Temperature, 20 C to 25 C (68 F to 77 F). Do not store above 30 C (86 F).
Protection Keep the product in the original container, tightly closed, and protect from excess moisture.
Child Safety Keep this medicine, and all medicines, strictly out of the reach of children.

Disposal Instructions

Regulatory documents specify that unused or expired Anasin must be disposed of properly. The preferred method is to utilize a drug take-back program or mail-back program when available. If those options are not available, the medicine should be mixed with an undesirable substance (such as dirt or used coffee grounds), placed in a sealed bag or container, and disposed of in household trash. Do not flush the product down a toilet or pour it down a sink unless the drug is explicitly listed on a regulatory authority’s flush list.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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