Common use

Symmetrel is a versatile medication containing the active ingredient amantadine, prescribed as both an antiviral agent for the prevention and treatment of influenza A infections and as a Parkinson treatment to manage symptoms of Parkinson's disease and drug-induced movement disorders. This dual-action medication has been a cornerstone of neurological and antiviral therapy for decades.

As an antiviral, Symmetrel works by blocking the actions of influenza A viruses in the body, preventing viral replication and reducing the severity and duration of symptoms when taken early in the course of infection. As a dopamine-enhancing agent for Parkinson treatment, amantadine helps alleviate characteristic symptoms including muscle stiffness, tremors, poor muscle control, and involuntary movements (dyskinesia). By increasing dopamine release and blocking its reuptake in the brain, Symmetrel helps restore more normal movement patterns and improve quality of life for patients with movement disorders.

When you buy Symmetrel online, you receive a medication that addresses two distinct medical needs. Symmetrel generic amantadine provides the same clinical benefits as the brand-name product, making effective treatment for both influenza A and Parkinson's disease more affordable and accessible.



Dosage and direction

Take Symmetrel orally with a full glass of water, with food or milk to minimize stomach upset. Swallow the tablet or capsule whole — do not crush it. For best results, take amantadine at the same time each day to maintain consistent blood levels. The usual dosage range is 100 to 200 mg daily, adjusted according to body weight and the specific condition being treated.

The recommended dosing varies by indication:

1. Parkinson treatment:

The starting dose for adults is typically 100 mg once daily. After one to several weeks of assessment, your doctor may increase this to 100 mg twice daily based on your response and tolerability.

2. Treatment and prevention of influenza A infections:

For adults and children aged 13 years and older, the recommended antiviral dose is 200 mg daily. Children aged 9-12 years should take 100 mg twice daily. For children aged 1-12 years, the dose is calculated based on body weight as determined by the prescribing physician.

3. Prevention of influenza A after exposure:

Symmetrel should be started before or immediately after contact with an infected person and continued for at least 10 days following exposure.

Note: These dosing guidelines are provided for informational reference only. It is essential to consult with your healthcare provider before starting amantadine to determine the optimal dose for your individual needs and to achieve the best therapeutic results.



Precautions

Important safety information: Suicide attempts and deaths have been reported in patients treated with Symmetrel. Suicidal ideation has occurred in patients both with and without a prior history of psychiatric illness. Amantadine can exacerbate symptoms in patients with existing psychiatric disorders or a history of substance abuse, requiring careful monitoring throughout treatment.

Patients with a history of epilepsy should be closely monitored during Symmetrel therapy, as should those with congestive heart failure, peripheral edema, eczematoid dermatitis, or renal impairment. Do not use this medication in patients with untreated angle-closure glaucoma.

Careful observation is essential upon discontinuation or dose reduction of Symmetrel, as cases of Neuroleptic Malignant Syndrome (NMS) have been reported during withdrawal. NMS is a potentially life-threatening condition characterized by high fever, severe muscle rigidity, involuntary movements, altered consciousness, mental status changes, rapid heart rate, and blood pressure instability.

Do not consume alcohol during treatment with amantadine. Symmetrel should not be used during pregnancy or while breastfeeding without explicit medical guidance from your doctor. If you buy amantadine, always discuss your complete medical history with your healthcare provider first.



Contraindications

Symmetrel is contraindicated in individuals with known hypersensitivity to amantadine or any component of the formulation. It is also contraindicated in patients with a history of seizures or convulsions, gastric ulceration, severe renal disease, and during pregnancy. If you have any of these conditions, do not buy Symmetrel online without first consulting your physician.



Possible side effect

Symmetrel may cause a range of side effects. Serious adverse reactions requiring immediate medical attention include:

shortness of breath, even with mild physical exertion;

swelling or rapid weight gain;

feelings of depression, agitation, or aggression;

behavioral changes, hallucinations, or thoughts of self-harm;

decreased urination or inability to urinate;

high fever, muscle stiffness, confusion, sweating, rapid or irregular heartbeat, rapid breathing, or feeling faint (signs of NMS);

restless involuntary movements of the eyes, tongue, jaw, or neck; or

uncontrolled tremor or shaking.

Less serious side effects that may occur during Parkinson treatment or antiviral therapy include:

dizziness, drowsiness, or headache;

insomnia or unusual dreams;

nervousness or anxiety;

nausea, diarrhea, constipation, or loss of appetite;

dry mouth or dry nose; or

loss of balance or coordination.

If you experience any of these symptoms, discontinue use and contact your doctor promptly. Report any unusual side effects to your healthcare provider for proper evaluation.



Drug interaction

Symmetrel may interact with several classes of medications. Notable interactions include anticholinergic drugs such as atropine, dicyclomine, glycopyrrolate, hyoscyamine, mepenzolate, methscopolamine, propantheline, and scopolamine. Amantadine may also interact with quinine, quinidine, diuretics (such as triamterene and hydrochlorothiazide), and phenothiazines (such as prochlorperazine and thioridazine).

Interaction between two medications does not necessarily mean one must be discontinued. However, the combined effects may alter the therapeutic action of either drug. Consult your doctor for guidance on how these interactions should be managed during your treatment with this dopamine-enhancing movement disorder medication.



Missed dose

If you forget to take your dose of Symmetrel, take it as soon as you remember. If it is nearly time for your next dose or too late in the day, skip the missed dose and continue with your regular schedule. Do not increase or double your dose to compensate. Resume your usual dosing the next day at your regular time.



Overdose

Amantadine overdose can be life-threatening — deaths have been reported in overdose cases. Symptoms of Symmetrel overdose may include high fever, severe anxiety, intense headache, confusion, hallucinations, agitation, aggression, personality changes, tremor, balance and walking difficulties, rapid or irregular heartbeat, severely decreased urination, breathing difficulties, seizures, or loss of consciousness. If you experience any of these symptoms, call emergency medical services immediately.



Storage

Store Symmetrel at room temperature between 59-77 degrees F (15-25 degrees C), protected from light and moisture. Keep this medication out of reach of children and pets. Do not use after the expiration date printed on the packaging.



Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.