I am one of several forum members taking DM. I use it in the same way originally recommended for naltrexone by Dr. Bihari. The work referenced by Ashleyk by Dr. Hong and the availability of DM in pediatric cough medicines without a prescription is the basis for my substituting it for LDN.
I have been taking DM (Pedia Care Long Acting; one-half to one-third tsp. every night before bed) for six years now. I was diagnosed by the head of a university neurology department in 2001, and my symptoms have progressed very little in that time. My only other meds are generic regular sinemet, 25/ 100mg and 2X generic sinemet cr 50/200, plus 100mg amantadine.
My neuro calls me his "PD poster boy".