Interesting drug called Dilantin.  A book by Jack Dreyfus, founder of the 
Dreyfus Fund and a multimillionaire, called  : "A Remarkable Medicine Has Been 
Overlooked" reports on different conditions for which this drug has proved 
effective.  Parkinson's is one of them.  Another name for the drug is 
phenotoin.  Mr. Dreyfus was so impressed and so humane that he spent 80 million 
dollars and 30 years researching and writing about the drug and its beneficial 
effects.  The drug appears to be rather benign--not completely but much better 
than such as Zoloft, etc.   Best wishes,  pj