Symmetrel® (amantadine hydrochloride)

Alliance Pharmaceuticals Ltd.

Symmetrel® information courtesy of Alliance Pharmaceuticals Ltd.

Last updated 15 March 2011

This section provides a summary of the drug information for Symmetrel® (amantadine hydrochloride).

If you have any further questions about your Parkinson's Disease (PD) medication, or other aspects of your PD treatment, you should discuss these with your doctor or other healthcare professional.

  • Symmetrel® 100mg capsules

    Symmetrel®
    100mg capsules

  • Symmetrel® 50mg/5ml syrup

    Symmetrel®
    50mg/5ml syrup

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Amantadine is a weak indirect dopaminergic agonist, used as an antiparkinsonian agent, to treat extrapyramidal reactions, and for postherpetic neuralgia1.

Symmetrel® has been shown to be a low affinity antagonist at the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors. Overactivity of glutamatergic neurotransmission has been implicated in the generation of parkinsonian symptoms. The clinical efficacy of amantadine is thought to be mediated through its antagonism at the NMDA subtype of glutamate receptors. In addition, amantadine may also exert some anticholinergic activity2.

Symmetrel® acts within a few days, but may appear to lose efficacy within a few months of continuous treatment. Its effectiveness may be prolonged by withdrawal for three to four weeks, which seems to restore activity. During this time, existing concomitant antiparkinsonian therapy should be continued, or low dose L-dopa treatment initiated if clinically necessary2.

References

  1. Therapeutic Drugs. Dollery. 2nd Ed.
  2. Symmetrel SmPC

 

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Product information downloads

The information on this page printout is a general summary of the Symmetrel® medication product.

Please click on the links below to download more detailed information on the specific Symmetrel® medication, its handling and use.

Links go to the electronic Medicines Compendium (eMC) website.

Further detailed information on the specific Symmetrel® medication, its handling and use can be downloaded via the electronic Medicines Compendium (eMC) website (http://emc.medicines.org.uk/):

UK Patient Information Leaflets

UK Summary of Product Characteristics

Please note that SPCs are designed for healthcare professionals.

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Useful Links & References

 

Further Information

Alliance Pharmaceuticals Ltd
Avonbridge House
Chippenham
Wiltshire
SN15 2BB
United Kingdom