Symmetrel 100mg

Symmetrel(Amantadine Hydrochloride, USP) is designated generically as amantadine hydrochloride and chemically as 1-adamantanamine hydrochloride.
Symmetrel (Amantadine) is used to treat Parkinson's disease and conditions similar to those of Parkinson's disease. It also is used to prevent and treat respiratory infections caused by influenza A virus.
Amantadine comes as a capsule and liquid to take by mouth. It is usually taken once or twice a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take amantadine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Do not stop taking amantadine without talking to your doctor.

How it works:
It is known that Symmetrel helps release dopamine (a neurotransmitter which is similar to adrenaline in action and affects brain processes that control movement, emotional response, and ability to experience pleasure and pain) from the basal ganglia in the brain. However, it is not entirely understood why MS patients experience such an improvement in their fatigue when taking this drug.

Patients taking this drug are reported to experience a definite improvement in energy. Often their general outlook also improves, possibly because they are feeling so much better and able to do more.

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 (ED50) in tissue culture vary greatly (from 0.1μg/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.

Side effects:
Amantadine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• blurred vision
• dizziness
• lightheadedness
• faintness
• trouble sleeping

If you experience any of the following side effects, call your doctor immediately:

• depression or anxiety
• swelling of the hands, legs, or feet
• difficulty urinating
• shortness of breath
• rash