Symmetrel 100mg (Amantadine)

Symmetrel general information

What is Symmetrel used for?

Symmetrel capsules 100mg are used to treat Parkinson's disease, a neurological disorder that is either idiopathic, which means that its cause is unknown or secondary to a known cause such as stroke, head trauma or as a side effect of medication, particularly neuroleptic antipsychotics. Symmetrel 100 may be used alone as monotherapy, or in combination with other medications, like anticholinergic drugs or levodopa and helps relieve symptoms of Parkinsonism and Parkinson's disease, including tremor, bradykinesia (slowness of movement) and loss of balance. Symmetrel capsules 100mg are also used as prophylaxis to prevent signs and symptoms of infection caused by influenza A virus, particularly for those at high risk of infection, if vaccination is unavailable or contraindicated, and for those at risk of serious illness if they were to become infected, such as being immunocompromised or having lung problems; also to treat flu-like symptoms if administered within 48 hours.

How does Symmetrel work?

Symmetrel capsules 100mg contain amantadine, which is an antiparkinsonian drug with virostatic properties. The abnormal movements associated with Parkinsonism and Parkinson's disease are caused by low levels of dopamine, a neurotransmitter (chemical that allows communication between nerve cells) produced by certain neurons (nerve cells) in the brain and plays an important role in controlling muscle function and movement; it is important to have the correct levels of dopamine. The loss of dopamine seen in Parkinson's disease is due to slow and progressive destruction of the neurons that produce the dopamine in a certain area of the brain called the substantia nigra. Amantadine in Symmetrel 100 is thought to increase the amount of dopamine in the brain by enhancing the release of dopamine from central neurons and by delaying its re-uptake from the synapse, the gap between nerve cells across which chemical messages are sent from one nerve cell to another. The increase in dopamine levels helps the brain control muscle function and restore normal movement. Amantadine in Symmetrel 100 is also thought to exert some anticholinergic activity, which means that it blocks the binding of the neurotransmitter acetylcholine to its receptor in nerve cells and this action helps prevent the involuntary movements associated with Parkinsonism. The mechanism of action by which Symmetrel 100 prevents the growth of influenza A virus is not known but it is thought to be due to interference with a viral protein needed for the virus to infect the host cell and this inhibits the early stage of replication of the influenza A virus and checks the growth of virus.

What does Symmetrel contain?

Symmetrel capsules 100mg contain the active ingredient amantadine hydrochloride, used to treat Parkinson's disease and to treat and prevent symptoms of influenza A virus. They also contain: rape seed oil, lecithin, a wax blend composed of white beeswax and hydrogenated soya and vegetable oils, sodium ethyl hydroxybenzoate, gelatin, glycerol, iron oxide red CI 77491, sorbitol, sodium propyl hydroxybenzoate, titanium dioxide.

Treating Parkinson's disease with Symmetrel

Symmetrel capsules 100mg contain amantadine, which is an antiparkinsonian drug used to treat neurological symptoms that cause the abnormal movements associated Parkinsonism and Parkinson's disease. Parkinson's disease is a neurological disorder that is either idiopathic, which means that its cause is unknown, or secondary to a known cause such as stroke, head trauma or as a side effect of medication, particularly neuroleptic antipsychotics. Parkinsonism is caused by low levels of dopamine, a neurotransmitter (chemical that allows communication between nerve cells) produced by certain neurons (nerve cells) in the brain that plays an important role in controlling muscle function and movement. This loss of dopamine is due to slow and progressive destruction of the dopamine-producing neurons in the substantia nigra area of the brain. Amantadine in Symmetrel 100 is thought to increase the amount of dopamine in the brain by enhancing the release of dopamine from central neurons and by delaying its re-uptake from the synapse, the gap between nerve cells across which chemical messages are sent from one nerve cell to another. The increase in dopamine levels helps the brain control muscle function and restore normal movement. Amantadine in Symmetrel 100 is also thought to exert some anticholinergic activity, which means that it blocks the binding of the neurotransmitter acetylcholine to its receptor in nerve cells and this action helps prevent the involuntary movements associated with Parkinsonism. Symmetrel 100 may be used alone (monotherapy), or in combination with other medications, like anticholinergic drugs or levodopa and helps relieve symptoms of Parkinsonism and Parkinson's disease, including tremor, bradykinesia (slowness of movement) and loss of balance.

Treating symptoms of influenza A infection with Symmetrel

Symmetrel capsules 100mg contain amantadine, which is an antiparkinsonian drug with influenzal virostatic properties, which means that it specifically blocks the growth of the Influenza A virus. Although the mechanism of action by which Symmetrel 100 prevents the growth of influenza A virus is not known it is thought to be due to interference with a viral protein needed for the virus to infect the host cell and this inhibits the early stage of replication of the influenza A virus. Symmetrel capsules 100mg are used as prophylaxis to prevent signs and symptoms of infection caused by influenza A virus, particularly for those at high risk of infection, if vaccination is unavailable or contraindicated, and for those at risk of serious illness if they were to become infected, such as being immunocompromised or having lung problems; also to treat flu-like symptoms if administered within 48 hours.

What are the side effects of Symmetrel?

The most commonly reported side effects when taking Symmetrel capsules 100mg include: depression, anxiety, elevation of mood, agitation, nervousness, difficulty in concentrating, dizziness, light-headedness, headache, insomnia, lethargy, hallucinations, nightmares, ataxia, slurred speech, blurred vision, oedema of ankles, livedo reticularis (purplish-red blotchy spots on the skin), dry mouth, anorexia, nausea, vomiting, constipation, palpitations, orthostatic hypotension, excessive sweating.

When should Symmetrel not be used?

You should not use Symmetrel capsules 100mg if you:

• are allergic to amantadine or any ingredients in Symmetrel
• are pregnant or are breastfeeding
• have kidney or liver disease
• have or have had recurrent eczema, stomach ulcers, or cardiovascular disorders
• suffer from convulsions or psychiatric disorders
• are taking medicines that interact with Symmetrel, including: other antiparkinsonian drugs, like anticholinergics or levodopa (without discussion with your doctor), other medicines that act on the central nervous system, like sedatives, analgesics and alcohol, combination diuretics, like hydrochlorothiazide + potassium-sparing diuretics

What medications interact with Symmetrel?

Several medications interact with Symmetrel capsules 100mg and should either not be taken while you are taking Symmetrel or only after discussion and instruction from your doctor:

• Drugs that increase side effects with Symmetrel: other antiparkinsonian drugs, like anticholinergics or levodopa,
• Drugs that cause dangerous reactions with Symmetrel: other medicines that act on the central nervous system, like sedatives, analgesics and alcohol
• Drugs that affect Symmetrel: combination diuretics, like hydrochlorothiazide + potassium-sparing diuretics

How should Symmetrel be taken for Parkinson's disease?

You should take your Symmetrel capsules 100mg with a glass of water once daily and preferably with food to prevent stomach problems. Your doctor may increase the dose to one capsule twice daily, depending on your condition. You should see some benefit within a few days and should continue to take your Symmetrel 100 for as long as recommended by your doctor, which may be for a long time depending on your condition. For some people the effectiveness of Symmetrel 100 wears off after a few months of continuous treatment, if this is the case your doctor may recommend that you gradually reduce the dose and stop it for a few weeks, then start again.

How should Symmetrel be taken for influenza A?

You should take your Symmetrel capsules 100mg with a glass of water twice daily and preferably with food to prevent stomach problems, or once daily for children or adults over 65. For prophylaxis you should start taking Symmetrel as soon as possible after you have been exposed to the flu and keep taking it through outbreak for at least 10 days or until the outbreak of influenza A is over. For treatment you should start taking Symmetrel 100 within 48 hours of the first symptoms onset and then for 4-5 days.

How long should you take Symmetrel?

For Parkinson's disease you should continue to take your Symmetrel capsules 100mg for as long as recommended by your doctor, which may be for a long time depending on your condition. For prophylaxis against influenza A, you should start taking Symmetrel capsules 100mg as soon as possible after you have been exposed to the flu and keep taking it through outbreak for at least 10 days or until the outbreak of influenza is over. For treatment you should start taking Symmetrel 100 within 48 hours of the first symptoms onset and then for 4-5 days.

Missed dose of Symmetrel

If you miss a dose of Symmetrel capsules 100mg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose. Do not take a double dose.

How should Symmetrel be stored?

You should store your Symmetrel below 25°C in a cool dry place. Protect from moisture and heat.