Meds and you

Updated 11 February 2013

Amantadine

Amantadine is an antiviral drug used for the prevention of flu infections in high-risk patients. It is not recommended for the treatment of a flu infection that is already present.

0

Amantadine is the active ingredient of Symmetrel.

General information

Amantadine is an antiviral drug used for the prevention of flu infections in high-risk patients. It is not recommended for the treatment of a flu infection that is already present.

Amantadine also has some anti-Parkinsonian effects and is particularly effective if used in the early stages of the infection. By taking this drug twice a day, side effects of the disease may be reduced.

How does it work?

Flu : How amantadine works against the flu virus is not known. It may block reproduction of the virus and reduce its ability to enter cells.

Parkinson's disease: Parkinson's disease is associated with reduced levels of the neurotransmitter dopamine in the brain. Amantadine increase dopamine in the brain and/or inhibits the elimination of dopamine.

Fast facts

Drug schedule: Schedule 4

Available as: Capsules

What does it do? Amantadine has an anti-Parkinsonism and anti-viral effect

Overdose risk: Medium

Dependence risk: Low

Is Amantadine available as a generic? No

Is Amantadine available on prescription only? Yes

User information

Dietary advice: Amantadine can be taken with or without food

Stopping this medicine: If you are taking amantadine for flu, be sure to complete the full course. Amantadine must not be stopped abruptly when used for the treatment of Parkinson's disease as it can worsen the symptoms of the disease. Withdrawal symptoms may also be experienced. These include agitation, paranoia, anxiety, depression and confusion.

Prolonged use: When used for extended periods, your doctor may need to perform occasional tests to evaluate your liver and kidney function.

Special precautions

Consult your doctor before using this drug if:

  • you have liver or kidney disease,
  • you have a history of congestive heart failure or heart disease,
  • you have eczema,
  • you have mental or mood problems,
  • you are pregnant or plan to get pregnant,
  • you have glaucoma,
  • you have epilepsy,
  • you have a stomach ulcer, or
  • you are taking other medication.

Pregnancy: Avoid. Potential risk to the foetus has been reported. See above.

Breastfeeding: Avoid. This medication is passed through breast milk and may affect your baby adversely. Consult your doctor before use.

Porphyria: This medication is safe to use.

Infants and children: This medication is not intended for use in children under the age of 1 year.

Elderly: Caution is advised in the elderly as they may be more susceptible to unwanted side effects. An adjustment in dosage may be needed.

Driving and hazardous work: Caution is advised as use of this medication may lead to dizziness, light-headedness and/or sedation. Avoid such activities until you know how it affects you.

Alcohol: Avoid concomitant use of alcohol with this medication as it may add to the side-effects of the drug and may cause impaired coordination.

Possible side effects

Side effect

Frequency

Consult your doctor

Common

Rare

Only if severe

In all cases

Constipation/ urinary retention

x

x

Dry mouth

x

x

Headache

x

x

Skin discoloration

x

x

Swelling of legs

x

x

Psychotic episodes

x

x

Convulsions

x

x

Nausea

x

x

Insomnia

x

x

Nervousness

x

x

Blurred vision

x

x

Skin rash

x

x

Interactions

Drug interactions

Alcohol

Possible Impaired coordination

Other stimulants of the central nervous system (CNS)

Increased CNS stimulation

Co-trimoxazole

Possible increased toxicity of amantadine

Drugs with anticholinergic effects (antihistamines, tricyclic antidepressants, etc)

Increased anticholinergic effects: Dry mouth, constipation, blurred vision, urinary retention

Levodopa

Increased risk of levodopa toxicity

Quinine

Increased risk of amantadine toxicity

Overdose action

An overdose of this medication can be serious. Seek immediate emergency medical attention.

Recommended dosage

Adults:

Parkinson's disease: 100-200mg as 1-2 doses (maximum 400mg/day)

Antiviral: 100mg twice a day

Children:

Antiviral: 1-9 years: 4-8mg/kg/day (maximum 150mg/day)

> 9 years: (or over 45 kg) 100mg twice a day

This material is not intended to substitute medical advice, but is for informational purposes only. Please consult a physician for specific treatment and recommendations.

 

Read Health24’s Comments Policy

Comment on this story
0 comments
Comments have been closed for this article.