Amantadine – Dose, ROA, MOA, PK, PD, Indications & More

Dose and Dosage: The usual adult dose of amantadine for Parkinson’s disease is 100 mg twice daily, with the dosage sometimes increased gradually up to 400 mg daily if needed. For the treatment of influenza A, the recommended dose for adults is 200 mg per day, divided into two doses, for 3 to 5 days.

Frequency: Amantadine is typically taken orally once or twice daily, as prescribed by a healthcare professional.

Route of Administration (ROA): Amantadine is administered orally in the form of tablets or oral solution. In some cases, it may also be given intravenously in a hospital setting.

Mechanism of Action (MOA): The exact mechanism of action of amantadine is not fully understood. However, it is believed to exert its effects primarily by blocking the action of the neurotransmitter glutamate, thereby reducing excessive stimulation of the N-methyl-D-aspartate (NMDA) receptors in the brain. It may also enhance the release of dopamine and inhibit the reuptake of dopamine, leading to increased dopamine levels in the brain.

Pharmacokinetics (PK): After oral administration, amantadine is rapidly absorbed from the gastrointestinal tract and reaches peak plasma concentrations within 2 to 4 hours. It is primarily excreted unchanged in the urine, with a half-life of approximately 10 to 15 hours in adults.

Pharmacodynamics (PD): The pharmacodynamic effects of amantadine include its ability to modulate the activity of dopamine and glutamate neurotransmission in the brain. This results in improved motor function in Parkinson’s disease and reduced symptoms of influenza A infection.

Pathophysiology: Amantadine is indicated for the treatment of Parkinson’s disease and for the prevention and treatment of influenza A virus infections.

Indications: Amantadine is primarily indicated for the treatment of Parkinson’s disease and for the prevention and treatment of influenza A virus infections. It may also be used off-label for other conditions, such as fatigue associated with multiple sclerosis or traumatic brain injury.

Contraindications: Amantadine is contraindicated in patients with a known hypersensitivity to the drug or its components. It should also be avoided in patients with severe renal impairment or congestive heart failure. Caution is advised in patients with a history of seizure disorders, as amantadine may lower the seizure threshold.

Drug Interactions: Amantadine may interact with other medications, particularly those that affect the central nervous system or have anticholinergic effects. Concomitant use of amantadine with other anticholinergic drugs may increase the risk of side effects such as dry mouth, blurred vision, and urinary retention. Close monitoring and dose adjustments may be necessary when combining amantadine with other medications.

Monitoring and Laboratory Tests: Before initiating treatment with amantadine, healthcare providers may perform baseline assessments, including a review of medical history, physical examination, and laboratory tests (e.g., renal function tests). During treatment, regular monitoring of motor function, symptom control, and potential adverse effects is recommended to assess treatment response and detect any complications.

Always consult with a healthcare professional for personalized medical advice and recommendations regarding the use of amantadine or any other medications.


Why is this medication prescribed?
Amantadine is prescribed for two main purposes:

  1. Parkinson’s Disease: It is used to treat symptoms of Parkinson’s disease, such as stiffness, tremors, muscle spasms, and poor muscle control.
  2. Influenza A: Amantadine is also prescribed to prevent or treat certain types of influenza A virus infections.

How should this medicine be used?
For Parkinson’s disease, the usual dose is taken orally once or twice daily, with or without food. For influenza A, it’s typically taken as directed by the healthcare provider, usually for a specific duration of treatment.

Other uses for this medicine
In addition to its primary uses, Amantadine is sometimes used off-label to treat symptoms of fatigue associated with multiple sclerosis (MS) and traumatic brain injury (TBI). However, this usage should be under the guidance of a healthcare professional.

What special precautions should I follow?
Before taking Amantadine, inform your doctor about any allergies you have, especially to medications. Also, let your doctor know about any medical conditions you have, particularly kidney problems or seizure disorders. Use caution when driving or operating machinery, as Amantadine may cause dizziness or drowsiness.

What special dietary instructions should I follow?
There are no specific dietary restrictions associated with Amantadine use. However, maintaining a healthy diet and staying hydrated is always recommended.

What should I do if I forget a dose?
If you miss a dose of Amantadine, take it as soon as you remember. However, if it’s almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not double the dose to catch up.

What side effects can this medication cause?
Common side effects of Amantadine may include dizziness, drowsiness, headache, nausea, insomnia, and dry mouth. Less common but more severe side effects may include hallucinations, confusion, agitation, difficulty urinating, and worsening of Parkinson’s symptoms. Seek medical attention if you experience any severe or persistent side effects.

What should I know about storage and disposal of this medication?
Store Amantadine at room temperature away from moisture and heat. Keep it out of reach of children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard any unused medication or expired prescriptions.

In case of emergency/overdose
If you suspect an overdose of Amantadine or experience symptoms such as severe dizziness, difficulty breathing, or loss of consciousness, seek immediate medical attention or contact a poison control center right away.

Always consult your healthcare provider or pharmacist if you have any questions or concerns about Amantadine or its use.