In my geriatrics rotation in my Family Medicine residency, our main activity was seeing each other's patients on referral and going through all their meds, to reduce them to the absolute minimum. After I retired, my neighbor's elderly mother was having some difficulties and I told that same story. They asked her doctor to do that, and she improved. I think it's a huge issue, even now, with databases that can cross-reference known interactions. People who go to various specialists and don't have one doc who knows them and thinks about them are at particular risk for the 'add another med' problem.