Loading...
Loading...
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Amantadine Hydrochloride
Brand Name
Amantadine Hydrochloride
Generic Name
Amantadine Hydrochloride
Active Ingredient
AmantadineCategory
Influenza A M2 Protein Inhibitor [EPC]
Salt Form
Hydrochloride
Variants
40
References used for this content
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Amantadine Hydrochloride, you must consult a qualified healthcare professional.
| 100 mg/1 | CAPSULE | ORAL | 71335-0469 |
| 100 mg/1 | CAPSULE | ORAL | 71335-2664 |
| 50 mg/5mL | SOLUTION | ORAL | 55154-9444 |
| 100 mg/1 | CAPSULE | ORAL | 62135-609 |
| 100 mg/1 | CAPSULE | ORAL | 0904-7042 |
| 50 mg/5mL | SOLUTION | ORAL | 60687-797 |
| 100 mg/10mL | SOLUTION | ORAL | 68999-011 |
| 100 mg/1 | CAPSULE | ORAL | 71205-223 |
| 50 mg/5mL | SOLUTION | ORAL | 17856-0646 |
+ 28 more variants
Detailed information about Amantadine Hydrochloride
Amantadine is a unique pharmacological agent functioning as both an antiviral and a dopaminergic medication. It is primarily utilized in the management of Parkinson's disease, drug-induced extrapyramidal symptoms, and historically, the prophylaxis and treatment of Influenza A virus infections.
Dosage for Amantadine is highly individualized and depends on the specific condition being treated, as well as the patient's age and kidney function.
Amantadine is FDA-approved for use in children for the treatment of Influenza A, though it is rarely used for this purpose today due to viral resistance.
Because Amantadine is cleared by the kidneys, dosage adjustments are mandatory for anyone with a reduced Glomerular Filtration Rate (GFR).
Failure to adjust the dose in these patients can lead to severe neurotoxicity, including seizures and coma.
No specific dosage adjustments are typically required for patients with liver disease, as the drug is not significantly metabolized by the liver. However, caution is advised as these patients may have secondary renal issues.
Patients over the age of 65 are at a higher risk of side effects due to age-related declines in kidney function. Healthcare providers usually start elderly patients at the lowest possible dose (100 mg once daily) and monitor closely for confusion or hallucinations.
To ensure the best results and minimize side effects, follow these guidelines:
If you miss a dose, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and return to your regular schedule. Never double the dose to catch up, as this significantly increases the risk of adverse neurological effects.
Amantadine overdose is a medical emergency and can be fatal. Signs of overdose include:
In the event of a suspected overdose, call 911 or your local emergency services immediately. Treatment typically involves supportive care, intravenous fluids, and sometimes the administration of physostigmine to reverse central nervous system toxicity. Hemodialysis is not effective in removing Amantadine from the system.
> Important: Follow your healthcare provider's dosing instructions precisely. Do not adjust your dose or stop taking the medication without medical guidance, as sudden discontinuation can lead to a worsening of symptoms or a withdrawal syndrome.
Most patients taking Amantadine will experience some mild to moderate side effects as their body adjusts to the medication. These often diminish over time but should be monitored.
Amantadine is a potent medication that affects the central nervous system. Patients must be aware that its benefits come with significant responsibilities regarding monitoring and safety. It is not suitable for everyone, particularly those with certain underlying psychiatric or renal conditions. Patients should never share this medication with others, even if they have similar symptoms.
At this time, there are no FDA black box warnings for Amantadine. However, this does not mean the drug is without risk. Clinicians treat the warnings for suicidality and CNS toxicity with the highest level of clinical priority.
While rare, serious allergic reactions can occur. Symptoms include hives, difficulty breathing, and swelling of the face, lips, or throat. If these occur, seek emergency care immediately and do not take the medication again.
Amantadine must NEVER be used in the following circumstances:
Amantadine is classified as FDA Pregnancy Category C. This means that animal studies have shown evidence of teratogenicity (birth defects) at high doses, but there are no adequate, well-controlled studies in humans.
Amantadine is known to be excreted in human milk. Because it is a dopaminergic agent, it may also suppress prolactin secretion, potentially reducing the mother's milk supply. There is a risk of side effects in the nursing infant, such as vomiting, urinary retention, and skin rashes. Breastfeeding while taking Amantadine is generally not recommended. If the medication is essential for the mother's health, an alternative feeding method for the infant should be considered.
Amantadine's pharmacological profile is unique because it acts on multiple systems simultaneously.
Common questions about Amantadine Hydrochloride
Amantadine is a versatile medication primarily used to treat Parkinson's disease and drug-induced movement disorders. It helps reduce tremors, muscle stiffness, and the 'jerky' involuntary movements (dyskinesia) that often occur with long-term levodopa use. Additionally, it is FDA-approved as an antiviral to prevent or treat Influenza A infections, though this use has become less common due to viral resistance. Some doctors also prescribe it off-label for fatigue in multiple sclerosis or to aid recovery after a traumatic brain injury. It works by increasing dopamine levels in the brain and blocking certain glutamate receptors. Always take it exactly as prescribed by your healthcare provider for your specific condition.
The most common side effects of Amantadine include nausea, dizziness, lightheadedness, and insomnia. Many patients also experience a unique skin condition called livedo reticularis, which is a purplish, net-like mottling of the skin, usually on the legs. Other frequent issues include dry mouth, constipation, and swelling of the ankles or feet (peripheral edema). These side effects are often mild and may improve as your body adjusts to the medication. However, if they become bothersome or persistent, you should contact your doctor. It is important to rise slowly from a sitting position to avoid dizziness caused by blood pressure changes.
No, you should strictly avoid alcohol while taking Amantadine. Alcohol can significantly worsen the central nervous system side effects of the medication, such as dizziness, confusion, and drowsiness. Combining the two increases your risk of fainting, falling, and experiencing severe lightheadedness upon standing. In some cases, alcohol can even trigger serious psychiatric reactions or hallucinations when mixed with Amantadine. To ensure your safety and the effectiveness of the treatment, it is best to abstain from all alcoholic beverages. Discuss any concerns about alcohol use with your healthcare provider before starting the drug.
Amantadine is generally not recommended during pregnancy unless the potential benefits clearly outweigh the risks to the fetus. It is classified as FDA Pregnancy Category C, meaning animal studies have shown it can cause birth defects, including heart and bone malformations, but human data is limited. The drug is known to cross the placenta and reach the developing baby. If you are pregnant, planning to become pregnant, or suspect you might be pregnant, you must inform your doctor immediately. They will help you weigh the risks of the medication against the necessity of treating your condition. Effective contraception is usually advised for women of childbearing age while on this drug.
The time it takes for Amantadine to work depends on the condition being treated. For Parkinson's disease symptoms, many patients begin to notice an improvement in tremors and stiffness within 48 to 72 hours, though it can sometimes take up to two weeks for the full effect. If being used for the flu, it should be started within 24 to 48 hours of the first symptoms to be effective in shortening the illness. If you do not notice any improvement after two weeks of consistent use for movement issues, consult your doctor. They may need to adjust your dosage or re-evaluate your treatment plan. Do not stop taking the medication just because you don't feel immediate results.
You should never stop taking Amantadine suddenly without consulting your healthcare provider. Abruptly discontinuing the drug can cause a rapid worsening of Parkinson's symptoms, making it very difficult to move or perform daily tasks. More seriously, sudden withdrawal can trigger a life-threatening condition called Neuroleptic Malignant Syndrome (NMS), which causes high fever, severe muscle rigidity, and mental confusion. If you need to stop the medication, your doctor will provide a schedule to gradually taper your dose over several days or weeks. This allows your brain chemistry to adjust safely. Always follow the professional tapering plan provided by your clinic.
If you miss a dose of Amantadine, take it as soon as you remember. However, if it is nearly time for your next scheduled dose, skip the missed one and continue with your regular dosing schedule. Do not take two doses at once to make up for the one you missed, as this can increase the risk of serious side effects like hallucinations or seizures. If you frequently forget your doses, consider using a pill organizer or setting an alarm on your phone. Consistency is key to maintaining stable levels of the drug in your system. If you miss several doses in a row, contact your doctor for advice on how to restart.
Weight gain is not a common side effect of Amantadine; in fact, some patients report a loss of appetite (anorexia) and slight weight loss when they first start the medication. However, Amantadine can cause peripheral edema, which is fluid retention that leads to swelling in the ankles and feet. This fluid buildup can sometimes look like weight gain on a scale. If you notice a sudden, significant increase in weight accompanied by shortness of breath or severe swelling, you should contact your doctor immediately. This could be a sign of congestive heart failure rather than simple weight gain. Most patients do not experience significant changes in body fat while on this drug.
Amantadine can interact with several other medications, so it is vital to provide your doctor with a full list of everything you take. It is often taken alongside levodopa for Parkinson's, but it can interact poorly with anticholinergic drugs (like certain allergy or bladder medications), leading to confusion and dry mouth. It also interacts with certain 'water pills' (thiazide diuretics) and the live flu vaccine. Because it is cleared by the kidneys, any drug that affects kidney function can change how Amantadine works. Always check with a pharmacist or doctor before starting any new over-the-counter supplements or prescriptions. They will ensure that the combination is safe for your specific health profile.
Yes, Amantadine is widely available as a generic medication in both capsule and tablet forms, which is typically much more affordable than brand-name versions. The immediate-release 100 mg capsules and tablets, as well as the oral syrup, are all available generically. However, some specific extended-release versions used for dyskinesia, such as Gocovri, may still be under patent and only available as brand-name products. Generic Amantadine is required by the FDA to have the same active ingredient and the same efficacy as the original brand-name version (Symmetrel). Check with your insurance provider and pharmacist to see which version is most cost-effective for you.
Other drugs with the same active ingredient (Amantadine)
> Warning: Stop taking Amantadine and call your doctor immediately if you experience any of these serious reactions.
Prolonged use of Amantadine may lead to certain 'wearing off' effects where the drug becomes less effective for Parkinson's symptoms. Additionally, the skin mottling (livedo reticularis) may become more pronounced over years of use. There is also a risk of developing corneal deposits or chronic edema in the eyes, necessitating regular eye exams for long-term users.
No FDA black box warnings currently exist for Amantadine. However, the FDA does require prominent warnings regarding the risk of suicide, CNS depression, and the dangers of abrupt discontinuation.
Report any unusual symptoms or changes in behavior to your healthcare provider immediately. Side effects can often be managed by adjusting the dose rather than stopping the medication entirely.
Amantadine can cause significant changes in mental status. Patients with a history of schizophrenia, bipolar disorder, or severe depression must be monitored closely. There is a documented risk of increased suicidality and the development of 'impulse control disorders,' where patients cannot resist the urge to gamble, spend money, or engage in other risky behaviors.
Amantadine may increase the frequency or severity of seizures in patients with a history of epilepsy. Healthcare providers will weigh the benefits against the risks in these individuals.
Because Amantadine can cause fluid retention and peripheral edema, it may worsen pre-existing heart failure. Patients should report any sudden swelling or shortness of breath to their doctor immediately.
Amantadine has mild anticholinergic properties, which can increase intraocular pressure. Patients with narrow-angle glaucoma should use this medication with extreme caution.
To ensure safe use, your healthcare provider may require the following:
Amantadine can cause dizziness, blurred vision, and 'sleep attacks' (sudden onset of sleepiness). Do not drive, operate heavy machinery, or engage in dangerous activities until you know how this medication affects you. This is especially important when first starting the drug or after a dose increase.
Avoid alcohol while taking Amantadine. Alcohol can increase the central nervous system side effects of the drug, leading to extreme dizziness, confusion, and a higher risk of fainting or falls. In some cases, alcohol can trigger a toxic psychiatric reaction when combined with Amantadine.
Do not stop taking Amantadine suddenly. Abruptly stopping the medication can lead to a 'rebound' effect where Parkinson's symptoms become severely worse. More dangerously, it can trigger a condition similar to Neuroleptic Malignant Syndrome (NMS), characterized by high fever, rigid muscles, and mental confusion. If the drug needs to be stopped, your doctor will provide a tapering schedule to slowly reduce the dose.
> Important: Discuss all your medical conditions, especially kidney disease, seizure disorders, and mental health history, with your healthcare provider before starting Amantadine.
Amantadine is not known to interfere significantly with most common laboratory tests. However, it may rarely cause elevations in liver enzymes (AST/ALT) or bilirubin. Always inform the laboratory staff and your doctor that you are taking Amantadine before undergoing blood or urine tests.
For each major interaction, the primary management strategy is dose adjustment or increased monitoring. If you must take a drug that interacts with Amantadine, your doctor may lower your Amantadine dose or schedule more frequent blood tests to check your kidney function.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. This includes over-the-counter cold medicines, which often contain antihistamines with anticholinergic properties.
In these cases, a healthcare provider will perform a careful risk-benefit analysis:
There is a potential for cross-sensitivity with other adamantane derivatives, such as Rimantadine (another antiviral). If you have had an allergic reaction to Rimantadine, you should inform your doctor, as you are likely to be allergic to Amantadine as well.
> Important: Your healthcare provider will evaluate your complete medical history, including your kidney function and mental health status, before prescribing Amantadine. Always provide a full list of your current medical conditions.
Elderly patients (aged 65 and older) represent the largest group of Amantadine users, yet they are also at the highest risk for toxicity.
This is the most critical special population for Amantadine. Dose adjustments are required for any CrCl below 50 mL/min.
While the liver does not clear Amantadine, patients with severe liver disease (Child-Pugh Class C) often have 'hepatorenal syndrome' or other kidney issues. Caution is advised, and clinicians should monitor renal function closely in these patients.
> Important: Special populations require individualized medical assessment. Never start Amantadine if you are pregnant or breastfeeding without a detailed consultation with your specialist.
| Parameter | Value |
|---|---|
| Bioavailability | 86% - 94% |
| Protein Binding | ~67% |
| Half-life | 12 - 17 hours (Normal Renal Function) |
| Tmax | 2 - 4 hours (Immediate Release) |
| Metabolism | Minimal (<10% Acetylated) |
| Excretion | Renal 90% (Unchanged) |
Amantadine is classified as an Influenza A M2 Protein Inhibitor and a Dopaminergic/Antiglutamatergic Agent. It is related to Rimantadine (antiviral) and Memantine (an NMDA antagonist used in Alzheimer's disease).