To List Members Written from my own experience, not as a professional. 1) antihistamines and parkinson's Yes, antihistamines can have a small anti-parkinson effect while they go to work on sniffles or itches. . I was prescribed Benadryl for allergies AND its anti-parkinson efffect and for its tendency to cause sleepiness. One tablet in the evening - a much larger quantity than you usually get over-the-counter. I took the Benadryl for a couple of years, but stopped taking it because a) dry mouth was ruining my teeth and b) the family cat died and my itches faded away. It took a while to convince the insurance company to cover my Benadryl. I finally sent them a photocopy of a page from a parkinson text which mentioned that benadryl could improve parkinson symptoms. If you take an antihistamine or over-the-counter cold remedy and you are also taking antiparkinson drugs you may feel a little overdosed. This is something you should discuss with your pharmacist or doctor. Make them look up all the drugs you take in their reference books (don't trust memory). Better still, get a photocopy of the relevant pages for your personal parkinson files. 2) amantadine as diagnostic tool Response to regular Sinemet is sometimes used to confirm a diagnosis of parkinsons and eliminate 'look-alike' conditions. Some of us with parkinsons have had only a very minor improvement or none at all when taking Amantadine --thus it would not give a definite yes or no answer. Hope this helps Amme Rutherford Newfoundland