Yes, I've had metallic taste off and on for years, though I've never identified which medication does it. Also, I've had the grundgy problem of my toothbrush turning black and my hands depositing black marks on the bathroom basin when I wash my hands. At the same time my fingernails get a black stain under them. I've noticed it occurs most frequently when I have taken an anti-acid for indigestion along with my Parkinson medications. I think it is a reaction to certain chemicals that get mixed together with the medications we take. At least it keeps us on our toes trying to figure what's going on. (My solution for the longest onslaught of black stain was to wear bright finger nail polish to cover it.) The condition comes and goes. I never decided just exactly which drugs were interacting to cause this disgusting condition. Ugh! Bev