Joyce, I've used Amantadine (Symmetrel) since 1969, before Levodopa came on the market. It has been helpful to me in ways that are hard to define. First of all, I soon found out I couldn't tolerate more than one pill a day. My ankles would swell up and I couldn't get my shoes on. Also they discolored with red marks. Reducing the dosage from 2 to 1 did the trick. It is never advisable to take more than 3/day because of these side effects. When I have tried to stop taking it I feel so awful I've given up. But I can't say that I know how Amantadine helps me except that I feel better when I take it. Remember, I am one of those young onset patients and we react more favorably to most PD medications than later onset people. Also we do not suffer halllucinations and mental confusion from overdosing with PD meds as much as older onset people. Instead we are more likely to get dyskinesia. Besides helping me cope with PD Amantadine also helps as an anti-cold aid with its anti-flu virus vaccine qualities (that is what it was designed for in the first place. It was only by serendipity that they discovered it helped 60% of those with PD who took it.) That's about all the info I can honestly give you on my experience with Amantadine. Hope it helps. Actually I consider Amantadine one of the most innocuous meds for PD and one that should be tried before more toxic drugs are attempted. Bev 73/1953