Amantadine
Drug class: Dopaminergic Antiparkinsonian Agent
Amantadine（中文：金鋼烷胺）
Common Strengths[edit]
- Tablets: 100 mg
Drug Usage[edit]
Amantadine is utilized for:
- Treating dyskinesia associated with Parkinson's disease.
- Managing drug-induced extrapyramidal symptoms.
Mechanism of Action[edit]
The exact mechanism is not fully understood, but it is believed to:
- Increase dopamine release and inhibit its reuptake.
- Act as a weak NMDA receptor antagonist, which helps in reducing dyskinesia.
Route of Administration[edit]
Amantadine is administered orally.
Dosages[edit]
- Initial Dose: 100 mg once daily; may be increased based on response.
Side Effects[edit]
| Frequency | Adverse reactions |
|---|---|
| Common Side Effects | Dizziness |
| Nausea | |
| Insonia | |
| Serious Side Effects | Congestive heary failure exacerbation |
| Severe skin reactions (e.g. rash) | |
| Neuroleptic malignant syndrome |
Pharmacokinetics[edit]
- Onset Time: Effects may begin within 2 days, but full benefits can take up to 2 weeks.
- Duration: gnerally lasting 12 to 24 hours.
Drug Precautions[edit]
Pregnancy
Amantadine should be used during pregnancy only if clearly needed, as risks vs. benefits must be evaluated.
Breastfeeding
Excretion in breast milk is unknown; caution is advised.
Drug Monitoring Items
- Renal Function
- Regular assessment of renal function is critical, especially in elderly patients or those with pre-existing renal impairment. Amantadine is predominantly excreted unchanged through the kidneys, and impaired renal function can lead to increased plasma concentrations and prolonged half-life of the drug. Monitoring should include:
- Serum creatinine and blood urea nitrogen (BUN) levels.
- Estimated glomerular filtration rate (eGFR).
- Regular assessment of renal function is critical, especially in elderly patients or those with pre-existing renal impairment. Amantadine is predominantly excreted unchanged through the kidneys, and impaired renal function can lead to increased plasma concentrations and prolonged half-life of the drug. Monitoring should include:
- Mental Status
- Patients should be monitored for changes in mental status, including:
- Hallucinations, delusions, depression, and suicidality.
- Increased risk of neuroleptic malignant syndrome (NMS) symptoms upon abrupt discontinuation.
- Patients should be monitored for changes in mental status, including:
- Blood Pressure
- Blood pressure should be monitored regularly due to the risk of orthostatic hypotension, particularly in older adults.
- Liver Function
- Liver enzymes (AST and ALT should be checked periodically, especially in patients with liver disease or those experiencing symptoms suggestive of hepatic impairment.
- Seizure Activity
- For patients with a history of seizures, monitoring for seizure activity is advised as amantadine can lower the seizure threshold.
Drug Interactions
Amantadine may interact with:
- Anticholinergic drugs (increased side effects).
- Dopaminergic agents (potentially enhanced effects).
FAQ[edit]
How Should I Take the Tablet?
Take amantadine exactly as prescribed by your healthcare provider, typically with or without food.
What Should I Avoid While Taking?
Avoid alcohol and other CNS depressants while taking amantadine due to increased risk of drowsiness.
What Happens if I Miss a Dose?
Take the missed dose as soon as you remember unless it is close to the time of your next dose. Do not double up on doses.
