- Flu Slideshow: 10 Foods to Eat When You Have the Flu
- Natural Cold & Flu Remedies Slideshow
- Take the Cold & Flu Quiz
- What is amantadine, and how does it work (mechanism of action)?
- Is amantadine available as a generic drug?
- Do I need a prescription for amantadine?
- What are the side effects of amantadine?
- What is the dosage for amantadine?
- Which drugs or supplements interact with amantadine?
- Is amantadine safe to take if I'm pregnant or breastfeeding?
- What else should I know about amantadine?
What is amantadine, and how does it work (mechanism of action)?
Amantadine is a synthetic (man-made) anti-viral drug that can inhibit the replication of viruses in cells. To prevent a viral infection, the drug should be present before exposure to the virus. Clearly, this is not practical for most viral infections. It was initially used to prevent influenza A during flu season, and, if given within 24 to 48 hours of the onset of flu symptoms, to decrease the severity of the flu. Later amantadine was found to cause improvement in the symptoms of Parkinson's disease. Amantadine's mechanism of action in Parkinson's disease is not fully understood. Its effects may be related to its ability to augment (amplify) the effects of dopamine, a neurotransmitter in the brain, that is reduced in Parkinson's disease. Amantadine is less effective than levodopa in Parkinson's disease but can offer additional benefit when taken with levodopa. Amantadine was approved by the FDA in 1966.
What are the side effects of amantadine?
The most frequent side effects associated with amantadine that can appear after a few hours or several days of therapy include:
Less common side effects include:
Quick Guide10 Foods to Eat When You Have the Flu in Pictures
What is the dosage for amantadine?
Amantadine is taken once or twice daily with or without food. If it causes an upset stomach, it can be taken with food. The dosage for prevention and treatment of influenza A infections in adults is 200 mg daily. For treatment of influenza, amantadine should be started within 24 to 48 hours after the onset of signs or symptoms and should be continued for 24 to 48 hours after the disappearance of signs or symptoms. To prevent influenza, amantadine should be started as soon as possible after exposure to the influenza virus and continued for at least 10 days. Persons with reduced kidney function and elderly persons may need lower doses (or less frequent doses).
The dosage for treating Parkinson's or extrapyramidal symptoms is 100 mg twice daily.
Which drugs or supplements interact with amantadine?
- The benzodiazepine class of anti-anxiety drugs, for example:
- The tricyclic class of antidepressants, for example:
- dicyclomine (Bentyl)
- Certain antihistamines, for example:
- Opiate agonists, for example:
- Certain antihypertensive medications, for example:
Since amantadine amplifies the actions of dopamine in the brain, drugs which block the effects of dopamine should be avoided in persons taking amantadine when amantadine is used for the treatment of Parkinson's disease. Such drugs include haloperidol (Haldol), metoclopramide (Reglan), and phenothiazines, for example, thioridazine (Mellaril) or triflupromazine (Stelazine).
The use of the diuretics hydrochlorothiazide or triamterene (Dyazide; Maxzide) with amantadine can reduce the kidney's ability to eliminate amantadine. This can lead to high levels of amantadine in the blood and amantadine-associated toxicity.
Is amantadine safe to take if I'm pregnant or breastfeeding?
No well-controlled studies have been done in pregnant women to evaluate amantadine's safety. Physicians may choose to use amantadine during pregnancy when the potential benefits outweigh the potential but unknown risks to the fetus.
Amantadine is excreted into breast milk in low concentrations. Although no information is available on the effects in infants, the manufacturer recommends that amantadine be used cautiously in women who are breastfeeding.
What else should I know about amantadine?
What preparations of amantadine are available?
Capsule: 100 mg. Syrup: 50 mg/5 ml (teaspoon).
How should I keep amantadine stored?
Amantadine should be stored at room temperature between 15 C - 30 C (59 F - 86 F).
Reference: FDA Prescribing Information
Quick Guide10 Foods to Eat When You Have the Flu in Pictures
Multimedia: Slideshows, Images & Quizzes
Related Disease Conditions
Parkinson's disease is a slowly progressive neurological disease characterized by a fixed inexpressive face, a tremor at rest,...
Multiple Sclerosis Symptoms (Early, Body Areas Affected)
Multiple sclerosis (MS) symptoms vary from person to person, and can last for days to months without periods of remission....
Influenza (flu) is a respiratory illness caused by a virus. Flu symptoms include fever, cough, sore throat, runny nose, headache,...
Post-polio syndrome (PPS) is a group of signs and symptoms that show up two to four decades after the initial polio infection....
Fragile X Syndrome
Fragile X syndrome is the most common inherited form of mental retardation. It's caused by a mutation on the X chromosome. People...
Bird Flu (Avian Influenza, Avian Flu)
Bird flu (avian flu, avian influenza) infection in humans may result from contact with infected poultry. There is a vaccine to...
Treatment & Diagnosis
- Parkinsons Disease FAQs
- Flu: What to Do if You Get the Flu
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Generic Drugs, Are They as Good as Brand-Names?
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- Medication Disposal - What to Do with Old or Unusable Medication
- Dangers of Mixing Medications
Medications & Supplements
Prevention & Wellness
Daily Health News
Subscribe to MedicineNet's General Health Newsletter
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Top amantadine Related ArticlesComplete List
Avian Influenza (Bird Flu)Bird flu (avian flu, avian influenza) infection in humans may result from contact with infected poultry. There is a vaccine to prevent human infection with the H5N1 strain of the avian flu virus.
dimethyl fumarateDimethyl fumarate (Tecfidera) is a prescription medication used to treat adults with relapsing forms of multiple sclerosis. Side effects, drug interactions, dosage, storage, and pregnancy safety information should be reviewed prior to taking this medication.
Drug InteractionsDrug interactions occur frequently. Get facts about the types of drug interactions, what substances or other things that may interact with drugs such as OTC drug and prescription drugs, vitamins, food(s) (grapefruit), and laboratory tests. Find out how to protect yourself from potential drug interactions.
Drugs: What You Should Know About Your DrugsImportant information about your drugs should be reviewed prior to taking any prescription drug. Side effects, drug interactions, warnings and precauctions, dosage, what the drug is used for, what to do if you miss a dose, how the drug is to be stored, and generic vs. brand names.
Fragile X SyndromeFragile X syndrome is the most common inherited form of mental retardation. It's caused by a mutation on the X chromosome. People with Fragile X syndrome suffer from physical, social, emotional, speech, language, sensory, intelligence, and learning impairments. There is no definitive treatment for Fragile X, though there are ways to minimize the symptoms.
InfluenzaInfluenza (flu) is a respiratory illness caused by a virus. Flu symptoms include fever, cough, sore throat, runny nose, headache, fatigue, and muscle aches. The flu may be prevented with an annual influenza vaccination.
MS (Multiple Sclerosis) Symptoms and Treatments
Multiple sclerosis (MS) symptoms vary from person to person, and can last for days to months without periods of remission. Symptoms of MS include problems with the:
- Eyes (vision)
- Brain and nervous system
- Sexual problems
Treatment options vary depending on the type and severity of symptoms. Medications may be prescribed to manage MS symptoms.
Parkinson's DiseaseParkinson's disease is a slowly progressive neurological disease characterized by a fixed inexpressive face, a tremor at rest, slowing of voluntary movements, a gait with short accelerating steps, peculiar posture and muscle weakness, caused by degeneration of an area of the brain called the basal ganglia, and by low production of the neurotransmitter dopamine. Most patients are over 50, but at least 10 percent are under 40.
Parkinson's QuizParkinson's disease is common among neurodegenerative disorders. Do you know how it works? The causes? The symptoms? Take the Parkinsonâ€™s Disease Quiz to Test your knowledge of Parkinson's.
Post-Polio SyndromePost-polio syndrome (PPS) is a group of signs and symptoms that show up two to four decades after the initial polio infection. Symptoms of PPS include fatigue, pain, sleep disorders, muscle twitching, gastrointestinal problems, and weakness. Treatment focuses on slowing down to conserve energy and relieving symptoms with pain relievers.
rimantadinerimantadine (Flumadine) is a medication prescribed for the treatment and prevention of influenza A in adults, and for the prevention of the influenza A virus in children older than one year of age. Side effects, drug interactions, and pregnancy safety information should be reviewed prior to taking this medication.
teriflunomideteriflunomide (Aubagio) is a prescription drug prescribed to treat relapsing forms of multiple sclerosis (MS) in individuals with MS. Side effects, drug interactions, dosage, storage, and pregnancy safety information should be reviewed prior to taking this medication.