From the FDA Drug Label
Amantadine hydrochloride is indicated in the treatment of idiopathic Parkinson's disease (Paralysis Agitans), postencephalitic parkinsonism, and symptomatic parkinsonism which may follow injury to the nervous system by carbon monoxide intoxication. In the treatment of Parkinson's disease, amantadine hydrochloride is less effective than levodopa, (-)-3-(3,4-dihydroxyphenyl)-L-alanine, and its efficacy in comparison with the anticholinergic antiparkinson drugs has not yet been established.
Amantadine is indicated for the treatment of Parkinson's disease (PD), including idiopathic Parkinson's disease, postencephalitic parkinsonism, and symptomatic parkinsonism. However, it is less effective than levodopa in treating PD. The efficacy of amantadine compared to anticholinergic antiparkinson drugs has not been established 1.
From the Research
Amantadine is a viable treatment option for Parkinson's disease, particularly for managing refractory tremor and levodopa-induced dyskinesias, as evidenced by a recent chart review with long-term follow-up 2.
Key Points
- Amantadine can be used as adjunctive therapy in Parkinson's disease patients with refractory tremor and levodopa-induced dyskinesias.
- The typical starting dose is 100 mg once daily, which can be gradually increased to 100 mg twice daily if needed and tolerated.
- For extended-release formulations, the recommended dose is 274 mg once daily at bedtime.
- Common side effects include livedo reticularis, ankle edema, hallucinations, confusion, and dry mouth.
- Amantadine should be used cautiously in patients with renal impairment, and the dose should be reduced accordingly.
Efficacy and Safety
A recent study found that 62% of tremor patients improved and tolerated amantadine, while 74% of those with levodopa-induced dyskinesias improved and tolerated the drug 2. However, hallucinations occurred in 23% of patients, highlighting the need for careful monitoring and dose adjustment.
Clinical Considerations
Amantadine may be a valuable option for patients experiencing dyskinesias or those who have plateaued on levodopa therapy, as it has been shown to improve motor symptoms and reduce dyskinesias 3. The medication typically begins working within 1-2 weeks, and benefits should be reassessed periodically to determine if continued treatment is warranted.
Recommendation
Based on the most recent and highest quality study, amantadine should be considered as adjunctive therapy in Parkinson's disease patients with refractory tremor and levodopa-induced dyskinesias 2.