Why is this medication prescribed?

Amantadine is prescribed for several medical conditions, primarily because of its effects on the central nervous system and its antiviral properties. Here are the main reasons it’s prescribed:

• Parkinson’s Disease and Parkinsonism: Amantadine is used to treat symptoms of Parkinson’s disease and other conditions that cause similar symptoms (like drug-induced parkinsonism). It helps to improve muscle control and reduce stiffness, shakiness, and difficulty moving.
• Influenza A Treatment and Prevention: Amantadine has antiviral properties and was initially used to prevent and treat infections caused by the influenza A virus. However, due to the development of resistance by many strains of the flu virus, its use for this purpose has decreased.
• Fatigue in Multiple Sclerosis (MS): Amantadine is sometimes prescribed to help reduce fatigue in people with multiple sclerosis, a neurological condition that can cause significant tiredness and lethargy.
• Off-Label Uses: Occasionally, amantadine is used off-label for other conditions, such as treating attention deficit hyperactivity disorder (ADHD), depression, or to manage side effects from other medications.

Amantadine works by increasing the levels of dopamine in the brain, which helps to improve movement in Parkinson’s disease, and by preventing the virus from multiplying in the case of influenza.

How should this medicine be used?

Amantadine is a medication that is primarily used to treat and manage certain conditions, including Parkinson’s disease, drug-induced extrapyramidal symptoms (movement disorders), and sometimes influenza A. Here’s a detailed guide on how Amantadine should be used:

• Parkinson’s Disease and Extrapyramidal Symptoms: The usual starting dose is 100 mg once daily. Depending on the patient’s response and tolerance, the dose may be increased to 100 mg twice daily. Some patients may require higher doses, up to 400 mg per day, divided into multiple doses.
• Influenza A Treatment: For adults, the recommended dose is 200 mg per day, taken as either one 200 mg dose or two 100 mg doses for 5 to 10 days. In elderly patients or those with renal impairment, the dose may be reduced to 100 mg per day to reduce the risk of side effects.
• Influenza A Prophylaxis: The dose is typically 200 mg per day for adults, continued throughout the flu season or until the risk of exposure has ended.
• Extended-Release Formulations: If using an extended-release form, it is usually taken once daily, and the dosage may differ. Always follow the specific instructions provided by the healthcare provider.
• Method of Administration: Amantadine is taken orally, usually with or without food. However, taking it with food can help reduce stomach upset. The medication should be swallowed whole with a glass of water. Extended-release capsules or tablets should not be crushed or chewed, as this can release the drug all at once, increasing the risk of side effects.
• Timing: It’s important to take Amantadine at the same time(s) every day to maintain a consistent level in the bloodstream. If you miss a dose, take it as soon as you remember. If it is almost time for the next dose, skip the missed dose and resume your regular dosing schedule. Do not double the dose to catch up.
• Kidney Function: Amantadine is excreted by the kidneys, so dose adjustments are often required for patients with renal impairment.
• Elderly Patients: Older adults may be more sensitive to the effects of Amantadine, particularly its side effects, and often require lower doses.
• Avoid Abrupt Discontinuation: Do not suddenly stop taking Amantadine, especially if you have been on high doses, as it may lead to withdrawal symptoms or worsening of Parkinson’s disease symptoms. Gradual dose reduction is recommended under medical supervision.
• Interactions: Amantadine can interact with other medications, so it’s important to inform your healthcare provider of all medications, supplements, or herbal products you are taking. Combining Amantadine with central nervous system (CNS) stimulants, anticholinergic drugs, or other medications that affect dopamine levels can increase the risk of side effects.

Always follow the specific instructions provided by your healthcare provider, as individual needs and responses to the medication can vary.

Other uses for this medicine

In addition to its primary uses, amantadine can also be prescribed for:

• Traumatic Brain Injury: It may help with cognitive and motor function recovery following brain injury.
• Certain Drug-Induced Conditions: It can be used to manage symptoms induced by antipsychotic drugs, such as drug-induced Parkinsonism.

What special precautions should I follow?

Special Precautions:

• Kidney Disease: Amantadine is excreted through the kidneys, so dose adjustments may be necessary if you have impaired kidney function.
• Heart Disease: If you have a history of heart problems, such as heart failure or arrhythmias, inform your doctor. Amantadine can cause or exacerbate heart issues.
• Mental Health Conditions: Amantadine can cause or worsen psychiatric symptoms such as depression, anxiety, or hallucinations. Tell your doctor if you have a history of mental health disorders.
• Seizure Disorders: If you have epilepsy or a history of seizures, use amantadine with caution, as it may increase the risk of seizures.
• Drowsiness and Dizziness: Amantadine can cause drowsiness or dizziness. Avoid driving or operating heavy machinery until you know how the medication affects you.
• Orthostatic Hypotension: This medication can cause a drop in blood pressure when standing up, leading to dizziness or fainting. Stand up slowly to prevent this.
• Blurred Vision: Some people experience blurred vision while taking amantadine. If this occurs, avoid tasks that require clear vision.
• Psychiatric Effects: Watch for mood changes, confusion, or hallucinations, especially in older adults. Contact your doctor if these symptoms occur.
• Other Anticholinergics: Amantadine has anticholinergic effects, which can be enhanced when taken with other medications with similar properties, increasing the risk of side effects like dry mouth, constipation, or urinary retention.
• Dopamine Agonists: If you are taking other dopamine-related medications (e.g., for Parkinson’s disease), be aware of the potential for increased side effects.
• Alcohol: Alcohol can exacerbate the side effects of amantadine, such as dizziness and drowsiness. It’s advisable to limit alcohol consumption while taking this medication.
• Pregnancy and Breastfeeding:  If you are pregnant or planning to become pregnant, discuss the risks and benefits of taking amantadine with your doctor. The effects of amantadine on the unborn baby are not fully understood. Amantadine can pass into breast milk, so consult your doctor before breastfeeding.
• Regular Monitoring: Regular follow-up appointments with your doctor are important to monitor your response to the medication and to adjust the dosage if necessary.

Always consult with your healthcare provider for personalized advice and follow their recommendations closely.

What special dietary instructions should I follow?

There are no specific dietary restrictions for amantadine. However, maintaining a balanced diet and staying hydrated can support overall health and help manage potential side effects. It’s always good to follow any additional dietary advice provided by your healthcare provider.

What should I do if I forget a dose?

• Missed Dose: If you forget a dose of amantadine, take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose; do not double up to make up for it.
• Regular Schedule: To help remember your doses, try to take amantadine at the same time each day.

What side effects can this medication cause?

Amantadine can cause a variety of side effects, ranging from mild to severe. Not everyone will experience these side effects, but it’s important to be aware of them. Here are some of the potential side effects:

Common Side Effects:

• Nausea: Feeling sick to your stomach is one of the most common side effects.
• Dizziness: A common side effect, particularly when standing up quickly.
• Insomnia: Difficulty sleeping or disturbed sleep patterns.
• Dry Mouth: A frequent side effect that can be managed with sugarless gum or candy.
• Constipation: Some people may experience difficulty with bowel movements.
• Blurred Vision: Visual disturbances can occur, which might affect activities like driving.
• Loss of Appetite: Some people may experience a decrease in appetite.
• Swelling: Particularly of the ankles or feet (peripheral edema).
• Headache: Mild to moderate headaches can occur.

Less Common but Serious Side Effects:

• Orthostatic Hypotension: A significant drop in blood pressure when standing up, leading to dizziness or fainting.
• Hallucinations: Seeing or hearing things that are not there, more common in older adults or people with a history of psychiatric disorders.
• Confusion: Difficulty thinking clearly or remembering things.
• Mood Changes: Depression, anxiety, irritability, or agitation.
• Urinary Retention: Difficulty urinating, particularly in men with prostate problems.
• Tremors: Shaking or trembling, particularly in the hands.
• Livedo Reticularis: A condition characterized by a mottled purplish discoloration of the skin, usually on the legs.
• Seizures: Although rare, amantadine can increase the risk of seizures, especially in people with a history of epilepsy.
• Heart Problems: Such as arrhythmias (irregular heartbeats) or heart failure.
• Neuroleptic Malignant Syndrome (NMS): A rare but life-threatening condition that can occur if amantadine is stopped suddenly. Symptoms include high fever, muscle stiffness, confusion, and irregular pulse or blood pressure.
• Suicidal Thoughts: Particularly in people with a history of depression or other mental health disorders.

Allergic Reactions:

• Rash, Itching, or Hives: Signs of an allergic reaction.
• Swelling: Especially of the face, lips, tongue, or throat.
• Difficulty Breathing: A sign of a severe allergic reaction (anaphylaxis), which requires immediate medical attention.

If you experience mild side effects, such as nausea or dizziness, they may improve as your body adjusts to the medication. However, you should still report them to your doctor. If you experience severe side effects, such as hallucinations, confusion, or any signs of an allergic reaction, contact your healthcare provider immediately. Do not stop taking amantadine suddenly without consulting your doctor, as this can lead to withdrawal symptoms or worsening of your condition.

It’s important to have regular check-ups with your doctor while taking amantadine so that any side effects can be monitored and managed appropriately.

What should I know about storage and disposal of this medication?

Storage of Amantadine:

• Store Amantadine at room temperature, typically between 68°F to 77°F (20°C to 25°C).
• Keep the medication in its original container, tightly closed, and away from light and moisture.
• Do not store in the bathroom or any area with high humidity.
• Keep out of reach of children and pets.

Disposal of Amantadine:

• Do not flush Amantadine down the toilet or pour it into a drain unless instructed to do so by a pharmacist.
• When the medication is no longer needed or has expired, follow proper drug disposal methods, such as returning it to a pharmacy take-back program or following FDA guidelines for disposing of medications in household trash (mix with unappealing substances like dirt, cat litter, or coffee grounds, place in a sealed plastic bag, and then dispose of it in the trash).

In case of emergency/overdose

• Symptoms of Amantadine overdose may include severe drowsiness, confusion, agitation, hallucinations, irregular heartbeat, difficulty breathing, fainting, and seizures.
• If you suspect an overdose, seek emergency medical help immediately.
• Call your local emergency number (e.g., 911 in the U.S.) or the Poison Control Center at 1-800-222-1222.
• Provide as much information as possible about the amount of medication taken and the time of ingestion.

What other information should I know?

• Missed Dose: If you miss a dose of Amantadine, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. Do not take a double dose to make up for the missed one.
• Drug Interactions: Inform your healthcare provider about all other medications, supplements, and herbal products you are taking, as Amantadine can interact with other drugs, leading to increased side effects or reduced effectiveness.
• Side Effects: Common side effects include dizziness, lightheadedness, dry mouth, constipation, and blurred vision. Serious side effects can include mood changes, difficulty urinating, and swelling in the legs or feet. If these occur, contact your doctor promptly.
• Precautions: Inform your doctor if you have any medical conditions, especially those related to the kidneys, heart, or mental health. Be cautious when performing tasks that require alertness (e.g., driving), as Amantadine may cause dizziness or blurred vision.
• Alcohol and Amantadine: Avoid consuming alcohol while taking Amantadine, as it can increase the risk of side effects like dizziness and confusion.

Always follow your healthcare provider’s instructions regarding the use of Amantadine and consult them with any concerns or questions.