I also know that age can effect medication. Recently I had similar problems with some medication that was too strong for me, and I had to reduce the dose until I found the right strength to work without disagreeing with me. The genetic pharaclogy idea sounds good but I don't know how much it costs. I'd also like to try stem cells especially for my knee which is now bone on bone, to see if cartilage would regenerate. The same might work on my back. I did sign up will 23andme, a genetic testing group for research and family history. I got some information from them on drugs and medicines that could work for me. This was years ago but the data is still good. They had an issue with the FDA and had to stop giving out medical information until the last couple years when the FDA approved some of their results. 23andme now charges $199 for a test, but I do not know what kind of medical information you can get from them now. 19lin