I wonder if you can find doctors like Gerald Windler, MD in any of the social media sites. Come to think of it, when everybody has taken advantage of social media, the others can't just do it yet. For medicine per se, there are some caluses that should be followed. Rules of medicines: confidentiality and truthfullness. After all, we are talking of human lives and not just sharing of food, clothes and places, right?
We cannot exempt the fact though that in terms of communication, social networks are doing great. That is the reason why many can get some ideas from it. There is now Doximity which can be used by real doctors. I say real because only certified doctors can log there and actually use it.