The mechanism of action of amantadine in Parkinsonism: a review.

Studies of the mechanism of action of amantadine are reviewed. Data from pharmacological, behavioural and neurochemical experiments seem to indicate that the most likely effects of amantadine to be important in the alleviation of Parkinsonian symptoms are an indirect dopamine-releasing action and a direct stimulation of dopamine receptors. These effects may have a relative importance of approximately 4 : 1. Evidence favouring inhibition of dopamine uptake does exist, but the balance of opinion seems to be that this action is far too weak to contribute substantially to amantadine's action in vivo.