Your father-in-laws problem is probably his kidneys. When your kidneys aren't functioning at 100% it raises your BP. I know how frustrating this is, my husband had the same problem, but once his kidneys got back to normal, his BP has remained within normal range. I don't have an answer, but I would allow the docs to do whatever they feel is necessary to figure this out, as it's not healthy. Good luck to all of you.....
Yes the kidneys play a big role in controlling blood pressure with chemicals they release into the blood stream.
it sounds to me more like the blood pressure caused the kidney problem, and not the other way around
perhaps he should not rely totally on medication, but instead do all the lifestyle modifications that he can - especially losing weight, and aerobic exercise to induce vasodilation