Its not as open as that but its in the doctors best intrest to promote a certain brand. They always throwing samples at you even if you dont need them, and also have a particular drug they like to prescribe all the time. An example is when I go to one doctor she would always unload the same exact samples on me saying"I might need them later" even after I told her I still have a bunch left from when she gave me last time, and as far as scripts go she had one favorite drug she would write out no matter if I had a cold, flu, or an ear infection. If I asked for a differant drug I knew worked better for me from a differant doc she wouldnt budge for shit. When I go to a differant doc he has his favorite set of drugs and does the same. One time I asked for some generic vicodin for my ear infection, I mentioned a name I knew, he would insist on a differant generic. I asked him why but he wouldnt give a stright awnser, if it made no differance to him why couldnt he write the name I mentioned.
Im sure something similar has happend to most of you. And if that doesnt convince you my friends wife is a general doctor, she told me that some (not all) doctors get some sort of commision on the side based on how well they promote samples they give out , also little things like paid trips so long as they agree to use this drug "A" made by them instead of "B" which another pharmecutical produces.