My 78 year old father is currently taking Lanoxin, Warfarin and glyburide for heart support and diabetes. We are noticing he is now losing strength and mental capacity. His family physician of many years just shrugged when we asked about supplementation. Of course, a second opinion is out of the question, he is so afraid and stubborn about anything new . . . After researching interactions with these drugs, I feel there isn't much of anything he can take, but I was wondering about the B's, and perhaps some form of magnesium.