I avoid them when I can. When I can't I find it helps me to understand as much as possible why they are behaving as they do. Yesterday a nurse at our local clinic was dismissive of a holistic approach I was using and was explaining to her as a reason for delaying a blood test I was supposed to have. I was really angry - all the anger I have at conventional medicine letting me down and misleading and harming people a lot of the time surfaced in a flash. I didn't handle the situation as well as I'd like to have, but it did help me later in analysing it to recognise that a) she loves power; b) was probably subconsciously anxious about her personal health choice which she recommended to me and c) really wasn't my mother. Anyone in a position of power who abuses it is like a red rag to me, especially if it's a health or teaching practitioner. It gives me just that bit of distance to know that I have that red button, and that what I feared in childhood - being destroyed by someone 'in power' who is behaving unjustly - can no longer happen.
Others will have other strategies which I'll be interested to hear about.