Been there many times on different consulting gigs.

I presume you are not part of the executive suite. If so -- get out!

When in the trenches, I have found the best approach is to recognize that you can't change "them". It is not personal and you certainly need to look upon it all as absurdist theatre. Read some Albert Camus or Jean Paul Sartre to realize that your experience if far from unique.

You don't need medication; just shift your viewpoint.